A Noctuid Moth Spodoptera Litura Pertaining to Global Distribution, Crop Losses, Nutritional Needs, Preferred Host Interactive Effects and Anti-Herbivore Defences Evolve

A Noctuid Moth Spodoptera Litura Pertaining to Global Distribution, Crop Losses, Nutritional Needs, Preferred Host Interactive Effects and Anti-Herbivore Defences Evolve

Hamzah, A. A.

Faculty of Applied Sciences, Universiti Teknologi MARA, Perak Branch, Tapah Campus

DOI: https://doi.org/10.51584/IJRIAS.2025.10050003

Received: 12 April 2025; Accepted: 25 April 2025; Published: 27 May 2025

ABSTRACT

Spodoptera litura is a sporadically serious insect pest, being an extremely polyphagous and wide-ranging species. To date, this insect pest is well justified in terms of its polyphagousity on many economically important crops, thus necessitating the need to find effective action strategies to combat the threats of infestations and spreads, as delays can lead to considerable economic losses. Developing effective management strategies can be included to find potent insecticides that are safer for the user and consumer, besides control problem due to the problem of resistance development to several synthetic insecticides. The wider the range of potential candidates, the higher the likelihood of finding top performers as an alternative method to control S. litura infestations, especially on agricultural lands and reduce chemical pesticide over-reliance. This review addresses a brief discussion about a polyphagous lepidopteran, S. litura recovering the global extent of invasion, the damage it causes and host plant preferences. In the following objective is to explore feeding behaviours and the nutritional composition of a preferred host plant that required for S. litura to grow and develop. This review focus also related to identify and describe the role of plant-derived secondary metabolites that could exert toxic effects to S. litura and possibly decipher a serious polyphagous herbivore its uniquely different and crucial strategy types evolved to deal with anti-herbivore defence of host plants. In conducting the literature survey or finding published information for this review, various scientific resources were relied on such as PudMed, ScienceDirect, ResearchGate and Google Scholar. The keywords used for collecting literature were global distribution, economic losses, plant secondary metabolites and defence mechanisms related to S. litura. The chronological period in which the papers were published was not considered during the literature survey and review writing process because the primary focus was on selecting noteworthy works for the topics covered. The occurrence and economic importance of this insect vary from region to region, but commonly found in the Asia-Pacific region and has caused some specific problematic pest population reports in Europe and the United States (US). Different populations of S. litura may demonstrate differences in feeding preference and width of the host range to complete their development but are considered significant for a better chance to survive with wild plants, weeds, shade trees, ornamental, agricultural and horticultural crops as hosts. Looking to the mode of damage, this insect pest emergence is observed to be associated with food availability and climatic conditions during its larval stages and consumption rate varies depending on the instar. Severe damages sometimes can extend to the whole plant dies in field conditions. It is noted that the nutritional difference of the plant hosts significantly induce divergence to the growth performance, reproduction, feeding behaviour, as well as adult oviposition. In association with continuous usage of synthetic pesticides contributing in adverse effects such as pollution, health hazards and loss of biodiversity, while adoption of botanical pesticides leads to a healthy environment and sustainable agriculture. Based on this, the extensive range of chemical variations or notably amazing chemical diversity found in plants offers a wide selection of chemicals that have potential uses as botanical insecticides. Several plant families have been reported to contain plants with bioactive compounds or secondary metabolites effective against S. litura, including Asteraceae, Fabaceace, Meliaceae and others which were rich in flavonoids, alkaloids and terpenoids. As opposed to many secondary metabolites found in plants against herbivores, the insect pest used different mechanisms to resist these toxins or induce defence responses, such as releasing secretory proteins from salivary glands, detoxifying enzyme activities and highly sensitive olfactory sensory systems. Significantly, this review highlights the recent scenarios that explore the global habitats for S. litura, global agricultural impacts due to the damage it causes to various crops, food utilisation and the effects of host plant nutrients on the growth and development of S. litura, the effectiveness of botanical insecticides derived from plant extracts containing a wide variety of defensive secondary metabolites in response to the insect herbivory; and lastly, strategies used by the insect pest that have been utilised to overcome its host plants’ diverse chemical defences.

Keywords: Spodoptera litura, polyphagousity, plant-derived secondary metabolites, botanical insecticides, olfactory sensory systems

INTRODUCTION

In Japan, Spodoptera litura is called ‘night thief’ because it tends to feed voraciously on a wide variety of plants by the night-active last instar larvae to avoid predators that hunt during the daytime such as from a group of birds (Zhang et al., 2021; Shivankar et al., 2008). Its native habitats spread across the globe and it has become one of the most pestiferous insects found worldwide. Exacerbating the longstanding challenges to control the insect pest, owing in part to adaptations of different plants around the world, resistance to insecticides, the extraordinary ability for detoxification and tolerance to many plant secondary metabolites, a great expansion of its detoxification gene families and gustatory receptor genes, long-distance migration contributed to the expansion of its territories and developed genomic uniformity in Asia, high fecundity and so forth (Zhang et al., 2021; Lin et al., 2019; Tong et al., 2004) that could cause so palpably loss to agricultural production.

It is predicted that more than 2,000 plant species from 189 families contain many bioactive secondary metabolites that are present in plant organs such as leaves, stems, roots and flowers, known to have insecticidal properties (Sharma et al., 2012; Isman, 2006; Rao et al., 2005). This is tremendously fruitful as an alternative method to currently use chemical insecticides against S. litura. The principal plant metabolites that impart such activity include flavonoids (Aboshi et al., 2018), terpenoids (Liu et al., 2021), alkaloids (Sun et al., 2012), acetogenins (Leatemia & Isman, 2004) and phenolics (Gautam et al., 2021). Even though plant metabolites can be used to deter or harm insect pests including S. litura larvae but undermined by exhibiting antiherbivory strategies related to the ability to detoxify and sequester toxic compounds in their diet using detoxifying enzymes such as cytochromes P450, carboxyl/cholinesterases, glutathione S-transferases (GST) and transporters such as ATP-binding cassette (ABC) transporters in insecticide resistance development (Hilliou et al., 2021).

Field resistance of S. litura to many chemical insecticides (Tong et al., 2004) caused further studies to be done in the future to understand its life cycle, feeding habits and habitat preferences, which help in identifying vulnerable stages for control and understanding how the insect pest interacts with its environment. Knowing which crops are susceptible to S. litura infestation helps in targeting control efforts as well, thus preventing economic losses. Furthermore, identifying factors influencing population growth and spread such as temperature, humidity and food availability, helps in predicting outbreaks and implementing timely control measures. Lastly, studying the mechanisms by which S. litura develops resistance (e.g., metabolic detoxification, target-site mutations and intestinal bacterial resistance) are important for developing new control strategies that bypass their resistance mechanisms.

Global Distribution and Economic Damages

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is one of the world’s most destructive pests to many agricultural crops in the Asian tropics. Global distribution ranges cover tropical and temperate Asia, Australasia and the Pacific Islands (Kranz et al., 1977). This pest is a transboundary or highly migratory insect capable to spread across the world due to its natural distribution capacity that could migrate over long distances during adulthood to non-indigenous areas and nocturnal habits, which facilitating dispersion and oviposition on different hosts (Tojo et al., 2013). Tu et al. (2009) reported that the flight activity for this insect pest during the 72-hour tethered flight assay for male and female S. litura, respectively could fly for an average duration of 19.6 hours and 24.0 hours, and at a mean distance of 83.3 km and 105.4 km, which proven its great potential to undertake long-distance migratory flights. Thus, the long-distance dispersal of the insect pest could contribute to gene flow, evolutionary potential; and the spread of resistance genes at a regional and large spatial scale (Hu et al., 2023). Next, accidental introduction through international trade, for example, eggs or larvae may be observed on planting materials, cut flowers, or vegetables; or pupal stages residing in soil can be important sources to transfer the pest outside of its native distributional range. Generally, S. litura has a relatively long duration of the pupal stage, therefore it could travel long distances unless are crushed or destroyed. For instance, some sporadic outbreaks of the pest in glasshouses have been reported in the United Kingdom (UK) and Germany after the discovery of S. litura in association with aquatic plants imported from Indonesia and Singapore (Aitkenhead et al., 1974; EPPO, 2004; EPPO, 2010). Likewise, all interception records of S. litura in United States (U.S.) ports of entry on commodities entering the US were found on orchids (Dendrobium, Oncidium) which originated from Thailand and made more than 85% cases in many years, as notified by Gilligan & Passoa (2014). Global distribution of habitats for S. litura has been detected in 52 infected countries as reported by Bragard et al. (2019). Amongst them, Bangladesh, China, India, Japan, Laos, Malaysia and Taiwan have been invaded with the most widespread population of S. litura.

In crop production, this significant pest species has been reported to cause serious damage by larval feeding preference upon many economically important crops worldwide with profound reductions in both yield quantity and quality (Bragard et al., 2019). Severe infestation by this destructive insect pest could impair agricultural production and subsequently threaten the global food supply. Leafworm Spodoptera litura has been shown to be resistant to a wide range of insecticides which led to sporadic and the onset of an outbreak unpredictably; hence the consequences often devastating (Ahmad et al., 2007). To date, there are not much studies available online assessing the substantial economic losses caused by S. litura attacks to numerous agro-economic crops in Southeast Asia. In Malaysia, there are three prominent or publicly available articles reporting S. litura population attacking commercial crops. Firstly, Mamat & soon (1982) stated that one of the major pests faced by tobacco growers in Kelantan and Trengganu was S. litura, which heavily infested in farms where chemical insecticides were not applied. In a subsequent case, outbreak proportions in plantation nurseries of Acacia mangium due to S. litura attacks in Peninsular Malaysia have been highlighted by Intachat & Kirton (1997) and expected to be higher based on the number of pest species, as an intensive survey was not conducted. The folivorous insect also has been reported to cause the most serious in terms of degree of damage on young banana cultivar Pisang Mas (1–2 months after planting) in planted fields at Synergy Farm, Pulau Pinang, Malaysia, which percentage of plants infested and killed by the infestation more than 50% (Okolle et al., 2006). Furthermore, the moth also be found on other host crops, but damage speculated to be minimal or without further comprehensive investigation on its effects (Hamzah & Norsyazwina, 2020).

The case in Indonesia demonstrated reduction of soybean productivity can be reached more than 63% due to the invasion of larval S. litura attacks on leaves in soybean cultivation (Rahayu et al., 2023). Moreover, a survey report by Crop and Horticultural Plant Protection Agency of Lampung Province, Indonesia from 2010 to 2019 in all corn-producing areas at Lampung has denoted that this destructive insect pest only caused a minor impact or less severely effected to the host plant (1 to ≤ 25% of plant damage) (Fitriana et al., 2021). In other Southeast Asian country whereby maize productivity constraints associated with S.litura attacks have been reported in Philippines even though this pest occurs less frequently but results in moderate-to-high yield losses (Gerpacio et al., 2004). In a similar infested country, the common cutworm, S. litura could cause heavy damaged to eggplants (Navasero & Navasero, 2003). On top of the economic impact cases of S. litura worldwide have been reported in India, which turned down the crop production planted in fields and greenhouses, respectively, such as sweet pepper, tomato, capsicum, cucumber and cabbage (Sabir & Singh, 2013; Vashisth et al., 2012).

Diet Breadth for S. litura

The preferences and host range of S. litura encompass a field crops grown for food and fibre, plantation and forestry crops, besides certain noxious weed species (EFSA PLH Panel [EFSA Panel on Plant Health]) et al., 2019; Sushilkumar & Ray, 2018). Lin et al. (2019) reported that the polyphagous pest fed nearly 289 species of plants, which comprising 109 families globally. Of that, 23 species of crops are notable from Malaysia (Hamzah & Norsyazwina, 2020). Figure 1 shows some examples of damaging plant in Malaysia caused by S. litura larvae gregariously eating patterns, frequently leaving the leaves completely destroyed. Divergent selection on host plants, which those economically important crops infested by S. litura in Asia included Colocasia esculenta, cotton, flax, groundnuts, jute, lucerne, maize, rice, soybeans, tea, tobacco, vegetables (aubergines, Brassica, Capsicum, cucurbit vegetables, Phaseolus, potatoes, sweet potatoes, Vigna, etc.) (Natikar & Balikai, 2017). Besides, Mitra et al. (2021) reported that the tobacco caterpillar, S. litura could change or switch its host plant preferences in a similar mixed-crop field purposely to enhance larval digestion and metabolism in different ontogenic stages. The host switch as an advantageous behaviour for the insect pest that could shorten the development time and increase the eclosion success. In addition, the pest has been reported to cause multiple pest attack impacts or to form lepidopteran complexs with others substantial lepidopteran insect pest of crops (Hossain et al., 2021; Rahman et al., 2021; Aiswarya et al., 2018; Okolle et al., 2006). In terms of feeding preference, the effect of different parts of the plant host can be linked to the inconsistent growth and development speed performance of S. litura (Ye et al., 2022; Hu et al., 2020). Moreover, host plant preference during the larval stage also could develop behavioural isolation to S. litura in terms of mate choice and sexual isolation. Di et al. (2021) reported that female S. litura fed on an artificial diet preferred mates with males that were fed on the same diet and occasionally mated with males fed on natural hosts, which were tobacco or Chinese cabbage.

Phytonutrients and chemical plant defences

Plants are major dietary sources of macro- and micro-nutrients for insects, included S. litura that feed on varieties of host plant species, which differ with their quality of nutritional status (Ganguly et al., 2020; Shah et al., 2017). Those nutrients play important roles to support insect larval development, reproduction, fecundity and oviposition (Kang et al., 2021; Xue et al., 2010; Awmack & Leather, 2002). In previous study done by Vengateswari et al. (2020) revealed that host plant nutrients also could enhance immune defence mechanisms for the larvae of S. litura to eliminate the invading pathogenic bacteria such as Bacillus thuringiensis (Bt) infections. Besides, insects also could face great temporal and spatial variation in the quality of leaves that they were tend to eat. By different ways to overcome this obstacles, insects have evolved various intrinsic detoxification mechanisms, feeding behaviours, and/or limited food intake to a specific time of the season (Parry & McCullough, 2004). However, when plant-based and artificial diets have been compared in terms of the growth and development indices of S. litura such as larval and pupal growth index, demonstrably the total developmental index on the modified artificial diet could be higher than some important host plants preferred by S. litura (Ganguly et al., 2020). Nutrient requirement of S. litura from plant hosts also can be enhanced by the present of the potential functions of gut bacteria in S. litura larvae (Xia et al., 2020). These preliminary findings speculated that the gut microbiota of S. litura is important for feeding, digestion and utilisation of food. Moreover, the gut bacterial composition of S. litura can be varied when reared on different food supplies despite that most abundant in the same phylum Proteobacteria but belong at different family levels, such as Enterobacteriaceae when reared on taro leaves, followed by Pseudomonadaceae and Enterobacteriaceae on the artificial larval diet.

According to Lee (2010), the larval armyworm S. litura demonstrated behaviour and pysiological regulation of macro-nutrient intakes in different sexes. The study revealed that when S. litura was fed on two nutritionally complementary foods (a protein-rich diet and a carbohydrate-rich diet, respectively); females shown no difference in carbohydrate intake but regulated to a higher intake of protein than males, purposely to lay eggs. In contrast, males have a higher tendency to accumulate lipids in their body than carbohydrates they eat because they typically spread out in search of females during estrus, thus, lipid accumulation was thought to be an energy reservoir that helped males prepare for migration.

Plants synthesize  a number of chemical compounds, commonly known as secondary metabolites to offset insect attacks but not engage in primary processes such as growth, reproduction, photosynthesis or protein production (War et al., 2012). Its number amounting to more than 2,140,000 have been discovered in the plant kingdom (examples include more than 12,000 alkaloids, 40,000 terpenoids and 8,000 phenyl propanoids (Al-Khayri et al., 2023; Elshafie et al., 2023) and grouped into different classes such as alkaloids, terpenes, amines, glucosinolates, cyanogenic glucosides, quinones, phenolics, peptides and polyacetylenes (Jamwal et al., 2018). Many secondary metabolites demonstrate a number of different mechanisms to control pests (Divya et al., 2024, Ling et al., 2019; Kortbeek et al., 2018). Amongst all, isoprene-derived terpenoids have most often proven effective, followed by alkaloid and phenolic compounds (Boulogne et al., 2012). Meanwhile, a high amount of nitrogen content in plant tissue could boost the growth and development of insect pests (Biswas et al., 2013; Awmack & Leather, 2002).

In a different way upon anti-herbivore defence which is related to the  rational applications of plant growth promoting rhizobacteria (PGPR) that could induce of systemic resistance to overcome insect infestations included S. litura attacks, concisely prevent the use of the agrochemicals besides enhance the plant growth and yield as well (Ling et al., 2022; Kousar et al., 2020; Bano & Muqarab, 2017). Example alleviated defenses stimulated by PGPR against a notorious leaf damaging pest on tomato leaves, S. litura, were raising in proline production, elevated activities of antioxidant enzymes, induction in the activities of protease and polyphenol oxidases, increased contents of phenolics, protein and chlorophyll (Bano & Muqarab, 2017). Further induced defence mechanisms by stimulating the expression levels of defence-related genes encoding allene oxide cyclase (AOC), allene oxide synthase (AOS), lipoxygenase D (LOXD) and proteinase inhibitor (PI-II) in tomato leaves (Ling et al., 2022). In a following study, Cortez Jr. et al. (2024) ascertained corn defence mechanisms against S. litura infestation. Their findings suggested that PGPR could enhance corn resistance to S. litura by feeding and oviposition deterrents for PGPFR-treated plants.

Figure 1:  S. litura Fab. (Lepidoptera: Noctuidae) infesting four different wild plant species in Malaysia which are a) taro (Colocasia esculenta, b) pink lotus (Nelumbo lucifera), c) sawah flowering rush (Limnocharis flava [L.] Buchenau) and d) Unknown plant species.

Some metabolites from plants can inhibit the growth of Spodoptera litura larvae or kill them; for example quercetin negatively affected the mid-gut of S. litura from Euphorbia hirta L (Selin-Rani et al., 2016). Next, β-caryophyllene [(1R,4E,9S)-4,11,11-trimethyl-8-methylene bicyclo [7.2.0]undec-4-ene], a natural sesquiterpene was found as an essential oil in many plants like Syzygium aromaticum, Piper nigrum and Cannabis sativa revealing its insecticidal, genotoxic and cytotoxic potentials against S. litura (Mahajan et al., 2022). Meanwhile, Su et al. (2017) studied the effect of various flavonoids, lectins and phenyl β-D-glucoside on larval survival, weight and activities of digestive (total serine protease and trypsin); and detoxifying (esterase and glutathione-S-transferase) enzymes of S. litura larvae at 7 days after treatment through a diet incorporation assay, convincingly demonstrating various toxic effects against the larvae of targeted insect pest in a laboratory setting. Furthermore, the harmful effects on the growth and development of second instar larvae (6 days old) of S. litura using different phenolic compounds purified from the medicinally important plant, Acacia nilotica, which is rich in polyphenols and may provide proficient alternative ways to control the insect pest in the field have been reported by Gautam et al. (2021). Considerable evidences existed that a synergistic effect of secondary plant metabolites acted as a mixture of bioactive constituents or botanical insecticides derived from a mixture of leaf extracts of Azadirachta indica (neem), Aglaia odorata, and Ageratum conyzoides (in a ratio of 1:1:1) was effective in killing the third instar larvae S. litura through both oral and topical application techniques (Hoesin et al., 2023). However, the topical application has been found to be the most favoured method in inducing mortality due to a higher level of mortality rate and a lower median lethal time (LT₅₀) value. The death of S. litura larvae was predicted because of exposure to toxic properties of active compounds in the plant extract used. For example, the main active compounds in neem (commonly known as azadirachtins) associated to a group of complex tetranortriterpenoids which harboring potent insect growth regulators. On the other side, the leaves of A. odorata reportedly contain several chemical compounds that show insecticidal properties, including germacrene-D, benzyl benzoate, benzyl salicylate, coumarins and alkaloids (Giang & Son, 2016; Sugijanto & Dorra, 2016; Udebuani et al., 2015). Contrarily, essential oils were the main insecticidal compounds present in A. conyzoides that contained several bioactive compounds with insecticidal properties, such as limonene, p-cymene, γ-terpinene and α-pinene as described by Bayala et al. (2014). Other examples of compounds with entomotoxic properties derived from ethanolic extracts of A. conyzoides leaves are flavonoids, alkaloids and coumarins (Chahal et al., 2021).

The more likely potential candidate to exhibit deadly insecticidal properties against S. litura is natural coumarin. Coumarin is a phenolic compound that can be assimilated into a toxic compound and affects insect midgut (Rao et al., 2017). The entomotoxicant has been tested against S.litura through transcriptome- based toxicology analysis, resulting in significantly inhibited effects on the growth and development of S. litura larvae, specifically impaired detoxification enzymes and glycometabolism (Xia et al., 2023). Laterally, essential oils with insecticidal activity belong to Thymus vulgaris and Satureia hortensis, respectively, and could kill more than 90% of S. litura larvae as reported by Isman et al. (2001). Thymol and carvacrol are both monoterpenoid phenols in insecticidal oils were found to be the major components for both assessed plants, ultimately responsible for the death of the insect host. Some binary mixtures like trans-Anethole acted synergistically with thymol, citronellal and α-terpineol, respectively whereby they were efficacious to cause acute toxicity and feeding deterrence against S. litura (Hummerbrunner & Isman, 2001). In view of the complexity of insect-herbivore interactions, there is also the potential for plant secondary metabolites to play an essential role in mediating interaction between S. litura and its natural enemy for indirect defence. Such a citing report by Du et al. (2022) found that Chinese cabbage could emit specific volatile substances (limonene, linalool and hexadecane) to attract the parasitic wasp, Microplitis similis against S. litura larvae.

Another specialised metabolite with insecticidal activity against S. litura larvae with success is octacosane (Ponsankar et al., 2016). The chemical compound was derived from Couroupita guianensis L. flower and showed high mortality against S. litura third instar larvae by damaging the gut epithelial layer and brush border membrane (BBM). A following study by Ponsakar et al. (2020) screened the antifeedant activity of the bioactive compound cucurbitacin E from Citrullus colocynthis L. Schrad (Cucurbitales: Cucurbitaceae) on different instar larvae of S. litura. The sublethal dose at 50 parts per million (ppm) displayed a high mortality rate in a dose-dependent way across all the instars. Besides, Vasantha-Srinivasan et al. (2016) evaluated larvicidal activity, inhibitors of the development and behavioural changes of S. litura, which were induced by the crude volatile oil belong to Piper betle leaves (Pb-CVO) in insecticidal bioassays. The study found that the Pb-CVO caused an acute mortality rate at concentrations of 1.0 and 1.5%, respectively, and its twenty constituents were significant inhibitors to the development and also caused behavioural changes of S. litura larvae. Likewise, a similar observed effect can be seen after S. litura larvae have ingested Db-Precocene I, a highly active bioactive compound from the grass Desmosstachya bipinnata (L.) Stapf. (Sundar et al., 2021). Alongside, Bis (2-ethylhexyl) phthalate (31.5%), a prominent active compound present in the methanolic leaf extract of Swietenia mahagoni Jacq. (Meliaceae) feasible as bio-rational plant product against the lepidopteran pest S. litura (Dinesh-Kumar et al., 2018).

Additional studies appraising on similar topic are catechin that isolated from the ethyl acetate crude stem extract of Artocarpus lacucha which could inflict the prominent toxicity effect against S. litura (24-hour 50% Lethal Dose value [LD50] of ~8.37 µg/larva) (Ruttanaphan et al., 2023); gallic acid at lower concentrations had a deleterious impact to the growth of S. litura but minor effects against its larval parasitoid Bracon hebetor (Hymenoptera: Braconidae) (Punia et al., 2021); bioactive metabolites in n-hexane extracts of Epaltes divaricata (NH-EDx) showed significant mortality rate in a dose-dependent way across all the instars against the A. aegypti and S. litura larvae (Amala et al., 2021); the methanolic flower extract of Nyctanthes arbor-tristis (Mx-Na-t) containing 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (3H-dp) and tyrosol (Ty-ol) showed higher toxicity effect to the third instar S. litura larvae (Divya et al., 2024); and the triterpenoid friedelin extracted from hexane extract of Azima tetracantha leaves showed highly effective larvicide against S. litura (Baskar et al., 2014). Without disregard other important plant secondary metabolites that responsible for various biological effects to S. litura related to the green-derived essential oils comprising of five major bio-active derivatives from Sphaeranthus amaranthoides (EO_Sa) which could activate toxicological responses against both third and fourth instar larvae of S. litura (Murfadunnisa et al., 2019); an essential oil blend from Alpinia galanga Zingiberaceae (Zingiberales) rhizomes and Ocimum basilicum Lamiaceae (Lamiales) leaves was ideal to be implemented with due respect to provide a synergistic on mortality effects for cypermethrin resistance of S. litura (Ruttanaphan et al., 2019); chloroform crude extracts of chick weed Ageratum conyzoides (Linn.) as a promising source of compounds that could cause significant larval mortality rate against pest S. litura (Vasantha-Srinivasan et al., 2024); and the ethanolic leaf extracts of two fig tree species, Ficus lyrata and Ficus auriculata; consisting of 12 and 15 active compounds against S. litura, respectively yielded higher mortality rates (Vasantha-Srinivasan et al., 2023).

More such secondary metabolites against S. litura for example reported by Koul et al. (2013) that found the thymol (5-methyl-2-isopropylphenol) content in thyme oil was thought as a potential acute toxicant, oviposition deterrent, ovicide or feeding deterrent to S. litura. Next. ononitol monohydrate originated from the ethyl acetate extract of Cassia tora L. and showed significant antifeedant, larvicidal and pupicidal activities towards S. litura (Baskar & Ignacimuthu, 2012). Meanwhile, Huang et al. (2014) reported that the essential oil of Pogostemon cablin (Blanco) Benth could exert potent effects such as antifeedant, larvicidal, growth inhibitory and pupicidal activities against S. litura. Similar substantial antifeedant, larvicidal and pupicidal activities and least lethal concentration 50 (LC₅₀) values were observed for chloroform extract of Ceasalpinea bonduc (L.) Roxb seeds (Baskar et al., 2011a).The findings in a study by Jeyasankar et al. (2012) revealed the crude ethyl acetate seed extract of S. pseudocapsicum contained of triterpenoids, flovonoids, alkaloids and quinines that showed higher efficiency of antifeedant activity against S. litura. Besides, the crude root methanolic extract of Aristolochia albida also could demonstrate a strong level of antifeedant activity to S. litura (Lajide et al., 1993). Observing moderate larvicidal effects were recorded for the acetone, chloroform, ethyl acetate, hexane and methanol leaf extracts of Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus against fourth instar larvae of S. litura after 24 hours of exposure (Kamaraj et al., 2008). Connected with that, dichloroethane (DCE) and methanol (Me) extracts of Melia dubia also could inhibit the growth in a dose-dependent manner to S. litura (Koul et al., 2000). Nevertheless, Murraya koenigii miraculin-like protein (MKMLP) was able to inhibit the trypsin-like activity and total protease activity of S.litura gut proteinases (SGP) by 81% and 48%, respectively, thus adversely affecting the growth and development of the insect pest (Gahloth et al., 2011). Baskar et al. (2011b) speculated that ethyl acetate and hexane leaf extracts of Aristolochia tagala Cham., respectively was able to produce higher feeding deterrence against S. litura at 5.0% final concentration. A deleterious effect on S. litura with regard to growth inhibition was reported by Jeyasankar et al. (2011) using a crystal compound (2,5-diacetoxy-2-benzyl-4,4,6,6-tetramethyl-1,3-cyclohexanedione) originated from the leaves of Syzygium lineare. A study on the influence of a trypsin inhibitor from Archidendron ellipticum (AeTI), which could inhibit the growth and serine digestive enzymes during larval development of Spodoptera litura, especially at early larval instars (1^st to 3^rd), has been reported by Bhattacharyya et al. (2007). Feeding deterrence was noticeable for the hexane extracts of Vernonia cinerea (73.44%); Cassia fistula (76.48%); and Vernonia cinerea (78.69%) after 24, 48 and 72 hours of exposure, respectively, due to the plant extracts providing an unpalatable taste to fresh castor leaf discs when fed by S. litura larvae in an antifeedant bioassay (Arivoli & Tennyson, 2020).

Remarkable (100%) antifeedant, larvicidal and pupicidal activities against S. litura were shown by the neem gum nano formulation (NGNF), a new pest control formulation using the aqueous extract of Neem gum (Azadirachta indica) (NGE) (Kamaraj et al., 2018). A similar finding was observed by Safder et al. (2022) when they examined the effectiveness of neem leaf extract (A. indica) against the second and third instar larvae of S. litura, respectively, and reported the mortality percentage received more than 70%, but under laboratory conditions. In addition to successful cases of secondary metabolites, several pure constituents from Wedelia prostrata essential oil, which are camphene (LC₅₀ = 6.28 μg/ml), γ-elemene, (LC₅₀ = 10.64 μg/ml), α-humulene (LC₅₀ = 12.89 μg/ml) and (E,E)-α-farnesene (LC₅₀ = 16.77 μg/ml) could highlight their promising insecticidal effect against larvae of S. litura (Benelli et al., 2018). Various solvents were implied to prepare crude extracts and obtained active fractions from Argemone mexicana L. (Papaveraceae) that could disrupt the growth and development of S. litura, particularly the least pupal weight, arrested pupation, nil fecundity, disturbed moulting, malformed moth and decreased adult life span (Malarvannan et al., 2008). An alternative bioefficacy of ethyl acetate extract of Artemesia nilagrica was studied by Raja et al. (2003) and observed notable amount of mortality activity against S. litura. Then, an anthraquinone aldehyde nordamnacanthal (1,3-dihydroxy-anthraquinone-2-al) found in the hexane extract of Galium aparine L. (bedstraw) and Rubia akane root powder, respectively has been recognised in vitro for its antifeedant propeties against S. litura (Morimoto et al., 2002). Even so, a study by Pavunraj et al. (2006) has shown that a 5% treatment of hexane extract of Excoecaria agallocha (L.) leaf extract resulted in significant antifeedant (73.08%), oviposition deterrent (83.71%) and ovicidal (65%) activities against S. litura. At a concentration of 0.05%, five plant extracts were tested against S. litura, consequently manifested diverse ovicidal activities with the highest in Cleistanthus collinus hexane (85.16%), followed by Murraya koeingii diethyl ether (83.60%), next Aegle marmelos ethyl acetate (76.14%), then hexane extracts of Strychnos nuxvomica (61.00%) and lastly Vitex negundo (52.02%) (Arivoli & Tennyson, 2013b). Afterwards, Cinnamomum zeylanicum hexane and Ocimum americanum ethyl acetate extracts exhibited more than 50% oviposition deterrent activity against S. litura at 1.0% concentration (Arivoli & Tennyson, 2013c).

The first trial report that notified the strong ovicidal and oviposition deterrent activities for Atalanta monophyla (L.) Correa crude leaf extract in hexane and included its active fraction against S. litura was reported by Baskar et al. (2012). Meanwhile, Pavunraj et al. (2012) revealed the ethyl acetate extract of Alangium salviifolium (L.F.) contained alkaloids, diterpenoids and saponins, which could exhibit profound larval mortality for the fourth instar larvae of S. litura under a laboratory setting. The same lead researcher (Pavunraj et al. (2011) explored the use of plant leaf extract of milkweed, Pergularia daemia, that possessed antifeedant activity against S. litura, typically the effect of crude leaf extract prepared in ethyl acetate has shown a convincing evidence of antifeedant activity (71.82%) at one percent concentration included its an active fraction known as 6-(4,7-hydroxy-heptyl) quinone with a similar effect on S. litura (68.31% at 2000 ppm). Despite that, five specific plant extract sources, which were prepared in different solvents at one percent concentration, respectively shown different acute feeding deterrent effect to S. litura, namely ethyl acetate extract of Strychnos nuxvomica (88.98%), hexane extracts of Vitex negundo (86.41%) and Murraya koeingii (81.46%), ethyl acetate extract of Zanthoxylum limonella (80.58%) and hexane extract of Abrus precatorius (78.61%) (Arivoli & Tennyson, 2013a). Then, the bio-efficacy of Lippia javanica as an antifeedant and larvicidal potential against the fourth instar larvae of S. litura at a 5% concentration has been confirmed in a study by Pavunraj et al. (2024), which both prepared in an ethyl acetate solvent. Among all, only one active fraction derived from Melochia corchorifolia leaf extract demonstrated significant antifeedant activity against S.litura either singly or in a co-formulated mixture with neem and karanj oil (Pavunraj et al., 2012).

In a related study on the topic, the insect pest was susceptible to the methanol extract of Sphaeranthus indicus, which caused antifeedant activity and exhibited developmental deformities for larvae and pupae as well (Ignacimuthu et al., 2006). In addition to what precedes, an exploratory study done by Raja et al. (2005) discovered new bioactive compounds isolated from crude ethyl acetate extract of Hyptis suaveolens which showed positive results for both oviposition deterrent activity and antifeedant activity against S. litura after being tested at 1000 ppm and 2000 ppm concentrations, respectively. Eventually, the essential oil from Lantana camara could produce high larval and larval-pupal mortality,whereas Curcuma  oil, the essential oil of Curcuma longa with insect growth regulator properties could cause adverse effects related to a high number of abnormal pupae and adults produced, respectively of S. litura (Javier et al., 2017).

Adaptations of S. litura to host plant secondary metabolites

Insect pests tolerate host plant secondary metabolites via different mechanisms such as detoxifying plant toxins, altering of the toxic compounds into favourable compounds for their growth and development, developing the choice of feeding on the basis of secondary metabolite concentration, quick engrossment and  expulsion as faeces and the participation of symbiotic intestinal microbes in order to tackle the effect of toxic plant secondary metabolites (Afroz et al., 2021; War et al., 2020). In the case of S. litura, behaviourally plastic host plants possesed by its larvae due to their ability to downregulate plant defence across different plants (Prajapati et al., 2020). Examples of adaptive mechanisms employed by S. Litura to downregulate plant defence by releasing oral secretions from salivary glands (such as labial salivary gland, ventral eversible gland and mandibular gland) known as effector proteins (Spitelleret al., 2004). Prajapati et al. (2020) reported that 267 out of 330 proteins were predicted as potential effector proteins from salivary glands of S.litura. Those effector proteins were identified in different families consisting of detoxifying enzymes (esterase, kazal-type serine protease inhibitors, metalloproteases and serine proteinase inhibitors), glucose oxidase, chemosensory proteins (odorant binding proteins and chemosensory proteins), calcium ion binding proteins (calumenin, calreticulin and armet), clip domain serine proteinase, lipases, phospholipases and peroxidase to mediate suppression of host plant defences. Among the effector proteins, employment of chemosensory proteins (CSPs) localised in chemoreceptive organs such as the apoprotein of S. litura CSP8 (SlCSP8) mainly expressed in the head of the S. litura larvae, especially the labrium can be used in identifying secondary metabolites in plants such as anthocyanins; and rhodojaponin III, a non-volatile secondary metabolite (Dong et al., 2024; Jia et al., 2021). Furthermore, findings in genomic studies of S. litura provide its genome information about the gene families encoding receptors for bitter or toxic substances and detoxification enzymes, such as cytochrome P450, carboxylesterase and glutathione-S-transferase, which massively expanded in this polyphagous species, facilitating its extraordinary ability to detect and detoxify many plant secondary metabolites (Cheng et al., 2017).

CONCLUSION

The current review delivers some specific problematic insect pest population reports on S. litura, which can be found in many countries, and is one of the major invasive insect pests globally. Its potential damages can affect crop production, economic returns for smallholder farmers and threaten global food security. Thus, comprehensive research efforts are required to understand its biology, behaviour and management strategies. Besides, the insect pest can adapt to many host plant species, which has caused the difficulty of effectively controlling it. Unveiling its feeding response, larval growth, development, survival and fecundity can be decreased on poor-quality host plants due to nutritional composition and/or secondary plant metabolites. Many published studies are available online on various plant extracts containing secondary metabolites that could provide promising effects in controlling S. litura larvae, such as repellent, antifeedant, larvicidal, ovicidal and pupicidal effects. Examples of plant secondary metabolites that are highly toxic to the insect pest include various alkaloids, flavonoids, phenolics, terpenes and terpenoids. Encountering the host plants’ diverse defences against herbivory, the insect pest has evolved to deal with or suppress the plant host defensive responses, such as downregulating the production of plant secondary metabolites by releasing secretory proteins or oral secretions, also known as effector proteins from salivary glands, using various detoxifying enzymes, highly efficient olfactory systems and many more.

REFERENCES

1. Aboshi, T., Ishiguri, S., Shiono, Y. and Murayama, T. 2018. Flavonoid glycosides in Malabar spinach Basella alba inhibit the growth of Spodoptera litura larvae. Bioscience, Biotechnology, and Biochemistry 82: 9-14.
2. Afroz, M., Rahman, M.M. and Amin, M.R. 2021. Insect plant interaction with reference to secondary metabolites: A review. Agricultural Reviews 42: 427-433.
3. Ahmad, M., Arif, M.I. and Ahmad, 2007. Occurrence of insecticide resistance in field populations of Spodoptera litura(Lepidoptera: Noctuidae) in Pakistan. Crop Protection 26:809–817.
4. Aiswarya,V.A., Bhosle, B.B. and Bhede, B.V. 2018. Population dynamics of major lepidopteran insect pests of cabbage. International Journal of Current Microbiology and Applied Sciences Special Issue-6: 236-239.
5. Al-Khayri, J.M., Rashmi, R., Toppo, V., Chole, P.B., Banadka, A., Sudheer, W.N., Nagella, P., Shehata, W.F., Al-Mssallem, M.Q., Alessa, F.M., Almaghasla, M.I. and Rezk, A. 2023. Plant secondary metabolites: The weapons for biotic stress management. Metabolites 13: 716.
6. Amala, K, Karthi, S., Ganesan, R., Radhakrishnan, N., Srinivasan, K., Mostafa, A.E.M.A., Al-Ghamdi, A.A., Alkahtani, J., Elshikh, M.S., Senthil-Nathan, S., Vasantha-Srinivasan, P. and Krutmuang, P. 2021. Bioefficacy of Epaltes divaricata (L.) n-hexane extracts and their major metabolites against the lepidopteran pests Spodoptera litura (fab.) and dengue mosquito Aedes aegypti (Linn.). Molecules 26: 3695.
7. Arivoli, S. and Tennyson, S. 2013a. Antifeedant activity, developmental indices and morphologenetic variations of plant extracts against Spodoptera litura (Fab) (Lepidoptera: Noctuidae). Journal of Entomology and Zoological Studies 1: 87-96.
8. Arivoli, S. and Tennyson, S. 2020. Antifeedant activity of leaf extracts against Spodoptera litura Fabricius 1775 (Lepidoptera: Noctuidae) highlighting the mechanism of action. London Journal of Research in Science: Natural and Formal 20: 67-80.
9. Arivoli, S. and Tennyson, S. 2013b. Ovicidal activity of plant extracts against Spodoptera litura (Fab) (Lepidoptera: Noctiduae). Bulletin of Environment, Pharmacology and Life Sciences 2: 140-145.
10. Arivoli, S. and Tennyson, S. 2013c. Screening of plant extracts for oviposition activity against Spodoptera litura (Fab). (Lepidoptera: Noctuidae). International Journal of Fauna and Biological Studies 1: 20-24.
11. Awmack, C.S. and Leather, S.R. 2002. Host plant quality and fecundity in herbivorus insects. Annual Review of Entomology 47: 817-844.
12. Bano, A. and Muqarab, R. 2017. Plant defence induced by PGPR against Spodoptera litura in tomato (Solanum lycopersicum L.). Plant Biology (Stuttgart, Germany) 19: 406-412.
13. Baskar, K., Duraipandiyan, V. and Ignacimuthu, S. 2014. Bioefficacy of the triterpenoid friedelin against Helicoverpa armigera (Hub.) and Spodoptera litura (Fab.) )Lepidoptera: Noctuidae). Pest Management Science 70: 1877-1883.
14. Baskar, K. and Ignacimuthu, S. 2012. Antifeedant, larvicidal and growth inhibitory effects of ononitol monohydrate isolated from Cassia tora L. against Helicoverpa armigera (Hub.) and Spodoptera litura (Fab.) (Lepidoptera: Noctuidae). Chemosphere 88: 384-388.
15. Baskar, K., Maheswaran, R. and Ignacimuthu, S. 2011a. Bioefficacy of Ceasalpinea bonduc (L.) Roxb. Against Spodoptera litura Fab. (Lepidoptera: Noctuidae). Archives of Phytopathology and Plant Protection 45: 1127-1137.
16. Baskar, K., Muthu, C., Raj, G.A., Kingsley, S. and Ignacimuthu, S. 2012. Ovicidal activity of Atalantia monophyla (L) Correa against Spodoptera litura Fab. (Lepidoptera: Noctuidae). Asian Pacific Journal of Tropical Biomedicine 2: 987-991.
17. Baskar, K., Sasikumar, S., Muthu, C., Kingsley, S. and Ignacimuthu, S. 2011b. Bioefficacy of Aristolochia tagala Cham. against Spodoptera litura Fab. (Lepidoptera: Noctuidae). Saudi Journal of Biological Sciences 18: 23-27.
18. Bayala, B., Bassole, I.H.N., Gnoula, C., Nebie, R., Yonli, A., Morel, L., Figueredo, G., Nikiema, J.-B., Lobaccaro, J.-M., Simpore, J., and Vanacker, J.-M. 2014. Chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils of plants from Burkina Faso. PLoS One 9:
19. Benelli, G., Govindarajan, M., Alsalhi, M.S., Devanesan, S. and Maggi, F. 2018. High toxicity of camphene and γ-elemene from Wedelia prostrata essential oil against larvae of Spodoptera litura (Lepidoptera: Noctuidae). Environmental Science and Pollution Research International 25: 10383-10391.
20. Bhattacharyya, A., Mazumdar, L.S. and Babu, C.R. 2007. Bioinsecticidal activity of Archidendron ellipticum trypsin inhibitor on growth and serine digestive enzymes during larval development of Spodoptera litura. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 145: 669-677.
21. Biswas, S., Panda, P., Guha, S. 2013. Effect of different does of nitrogen on insect pest attack and yield potentiality of okra, Abelmonschus esculentus (L.) Moench at terai ecology of west Bengal. Journal of Entomological Research 33: 219-222.
22. Bragard, C., Dehnen-Schmutz, K., Di Serio, F., Gonthier, P., Jacques, M-A., Jaques Miret, J.A., Justesen, A.F., Magnusson, C.S., Milonas, P., Navas-Cortes, J.A., Parnell, S., Potting, R., Reignault, P.L., Thulke, H-H., Van der Werf, W., Vicent Civera, A., Yuen, J., Zappala, L., Malumphy, C., Czwienczek, E. and MacLeod, A. 2019. Scientific Opinion on the pest categorisation of Spodoptera litura. EFSA Journal 17:5765, 35 pp.
23. Boulogne, I., Petit, P., Ozier-Lafontaine, H., Desfontaines, L. and Loranger-Merciris, G. 2012. Insecticidal and antifungal chemicals produced by plants: A review. Environmental Chemistry Letters 10: 325-347.
24. Chahal, R., Nanda, A., Akkol, E.K., Sobarzo-Sánchez, E., Arya, A., Kaushik, D., Dutt, R., Bhardwaj, R., Rahman, M.H., and Mittal, V. 2021. Ageratum conyzoides L. and its secondary metabolites in the management of different fungal pathogens. Molecules 26:
25. Cheng, T., Wu, J., Wu, Y., Chilukuri, R.V., Huang, L., Yamamoto, K., Feng, L., Li, W., Chen, Z., Guo, H., Liu, J., Li, S., Wang, X., Peng, L., Liu, D., Guo, Y., Fu, B., Li, Z., Liu, C., Chen, Y., Tomar, A., Hilliou, F., Montagne, N., Jacquin_Joly, E., d’Alencon, E., Seth, R.K., Bhatnagar, R.K., Jouraku, A., Shiotsuki, T., Kadono-Okuda, K., Promboon, A., Arunkumar, K.P., Kishino, H., Goldsmith, M.R., Feng, Q., Xia, Q. and Mita, K. 2017. Genomic adaptation to polyphagy and insectides in a major East Asian noctuid pest. Nature Ecology & Evolution 1: 1747-1756.
26. Cortez, Jr., A., Yoshinaga, N., Mori, N. and Hwang, S.Y. 2024. Plant growth-promoting rhizobacteria modulate induced corn defense against Spodoptera litura (Lepidoptera: Noctuidae). Bioscience, Biotechnology, and Biochemistry 88: 872-884.
27. Di, X.Y., Yan, B., Wu, C.X., Yu, X.F., Liu, J.F., Yang, M.F. 2021. Does larval rearing diet lead to premating isolation in Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Insects 12: 203.
28. Dinesh-Kumar, A., Srimaan, E., Chellappandian, M., Vasantha-Srinivasan, P., Karthi, S., Thanigaivel, A., Ponsankar, A., Muthu-Pandian Chanthini, K., Shyam-Sundar, N., Annamalai, M., Kalaivani, K., Hunter, W.B. and Senthil-Nathan. S.201 Target and non-target response of Swietenia Mahagoni Jacq. chemical constituents against tobacco cutworm Spodoptera litura Fab. and earthworm, Eudrilus eugeniae Kinb. Chemosphere 199: 35-43.
29. Divya, M., Karthi, S., Amalam K., Vasantha-Srinivasan, P., Han, Y.S., Al Obaid, S., Senthil-Nathan, S. and Park, K.B. 2024. Phytometabolites from coral jasmine flower extracts: Toxic effects on Spodoptera litura and enzyme inhibition in nontarget earthworm Eisenia fetida as an alternative approach. Environmental Research 252:
30. Dong, X., Huang, Y., Pei, Y., Chen, L., Tan, T., Xiang, F., Li, C. and Fu, L. 2024. A larval expressed chemosensory protein involved in recognition of anthocyanins in Spodoptera litura (Lepidoptera: Noctuidae). Journal of Economic Entomology 117: 2413-2424.
31. Du, Y.W., Shi, X.B., Zhao, L.C., Yuan, G.G., Zhao, W.W., Huang, G.H., Chen, G. 2022. Chinese cabbage changes its release of volatiles to defend against Spodptera litura. Insect 13: 73.
32. EFSA PLH Panel (EFSA Panel on Plant Health), Bragard, C., Dehnen-Schmutz, K., Di Serio, F., Gonthier, P., Jacques, M-A., Jaques Miret, J.A., Justesen, A.F., Magnusson, C.S., Milonas, P., Navas-Cortes, J.A., Parnell, S., Potting, R., Reignault, P.L., Thulke, H-H., Van der Werf, W., Vicent Civera, A., Yuen, J., Zappal, L., Malumphy, C., Czwienczek E. and MacLeod, A. 2019. Scientific opinion on the pest categorisation of Spodoptera litura. EFSA Journal 17:5765, 35 pp.
33. Elshafie, H.S., Camele, I. and Mohamed, A. 2023. A Comprehensive review on the biological, agricultural and pharmaceutical properties of secondary metabolites based-plant origin. International Journal of Molecular Sciences 24: 3266.
34. EPPO (European and Mediterranean Plant Protection Organization). Eradication of Spodoptera litura in Germany EPPO Reporting Service 2004 (08) 2004/117.
35. EPPO (European and Mediterranean Plant Protection Organization). Outbreak of Spodoptera litura in the United Kingdom. EPPO Reporting Service 2010 (07) 2010/126.
36. Fitriana, Y., Suharjo, R., Swibawa, G., Semenguk, B., Pasaribu, L.T., Hartaman, M., Rwandini, R.A., Indriyati, I., Purnomo, P. and Solikhin, S. 2021. Aspergillus oryzae and Beauveria bassiana as entomopathogenic fungi of Spodoptera litura Fabricius (Lepidoptera: Noctuidae) infesting corn in Lampung, Indonesia. Egyptian Journal of Biological Pest Control 31: 1-12.
37. Gahloth, D., Shukla, U., Birah, A., Gupta, G.P., Kumar, P.A., Dhaliwal, H.S. and Sharma, A.K. 2011. Bioinsecticidal activity of Murraya koenigii miraculin-like protein against Helicoverpa armigera and Spodoptera litura. Archives of Insect Biochemistry and Physiology 78: 132-144.
38. Ganguly, S. and Srivastava, C.P. 2020. Comparative biology of Spodoptera litura Fabricius on different food sources under controlled conditions. Journal of Experimental Zoology, India 23: 681-684.
39. Gautam, S., Samiksha, Chimni, S.S., Arora, S. and Sohal, S.K. 2021. Toxic effects of purified phenolic compounds from Acacia nilotica against common cutworm. Toxicon 203: 22-29.
40. Gerpacio, R.V., Labios, J.D., Labios, R.V. and Diangkinay, E.I. 2004. Maize in the Philippines: Production Systems, Constraints, and Research Priorities. Mexico, D.F.: CIMMYT.
41. Giang, P.M., and Son, P.T. 2016. GC and GC-MS analysis of the fresh flower essential oil of Cananga odorata (Lam.) Hook. f. et Th. var. fruticosa (Craib) J. Sincl. American Journal of Essential Oils and Natural Products 4: 9–11.
42. Gilligan, T. M. & S. C. Passoa. 2014. LepIntercept, An identification resource for intercepted Lepidoptera larvae. Identification Technology Program (ITP), USDA-APHIS-PPQ-S&T, Fort Collins, CO. [accessed at lepintercept.org].
43. Hamzah,A. and Norsyazwina, M.R. 2020. Crop damages by armyworm (Spodoptera litura F.) in Malaysia and control tactics. Asian Journal of Fundamental and Applied Sciences 1: 13-19.
44. Hilliou, F., Chertemps, T., Maïbèche, A and Goff, G.L. 2021. Resistance in the Genus Spodoptera: key insect detoxification genes. Insects 12: 544.
45. Hoesain, M., Suharto, S., Prastowo, S., Pradana, A.P., Alfarisy, F.K. and Adiwena, M. 2023. Investigating the plant metabolite potential as botanical insecticides against Spodoptera litura with different application methods. Cogent Food & Agriculture 9: 2229580.
46. Hossain, M.M., Singha, A., Haque, M.S., Mondal, M.T.R., Jiku, M.A.S. and Alam, M.A. 2021. Management of chilli insect pests by using trap crops. Thai Journal of Agricultural Science 54: 212−221.
47. Hu, Z., Yang, F., Zhang, D., Zhang, S., Yu, X. and Yang, M. 2023. Genetic diversity and fine-scale genetic structure of Spodoptera litura Fabricius (Lepidoptera: Noctuidae) in Southern China based on microsatellite markers. Animals 13: 560.
48. Hu, Z.Z., Xu, X.C., Pan, L., Li, M., Zeng, J., Muhammad, K.R., Xin, G.N. and Gai, J.Y. 2020. Resistance analyses of soybean organs to common cutworm (Spodoptera litura) at different reproductive stages. Soybean Science 39: 932-939.
49. Huang, S.H., Xian, J.D., Kong, S.Z., Li, Y.C., Xie, J.H., Lin, J., Chen, J.N., Wang, H.F. and Su, Z.R. 2014. Insecticidal activity of pogostone against Spodoptera litura and Spodoptera exigua (Lepidoptera: Noctuidae). Pest Management Science 70: 510-516.
50. Hummerbrunner, L.A. and Isman, M.B. 2001. Acute, sublethal, antifeedant, and synergistic effects of monoterpenoid essential oil compounds on the tobacco cutworm, Spodoptera litura (Lep., Noctuidae). Journal of Agricultural and Food Chemistry 49: 715-720.
51. Ignacimuthu, S., Maria, P.S., Pavunraj, M. and Selvarani, N. 2006. Antifeedant activity of Sphaeranthus indicus L. against Spodoptera litura Fab. Entomon 31: 41-44.
52. Intachat, J. and Kirton, L.G. 1997. Observations on insects associated with Acacia mangium in Peninsular Malaysia. Journal of Tropical Forest Science 9: 561-564.
53. Isman, M.B.. 2006. Botanical insecticides, deterrents and repellents in modern agriculture and an increasingly regulated world. Annual Review of Entomology 51: 45–66.
54. Isman, M.B., Wan, A.J. and Passreiter, C.M. 2001. Insecticidal activity of essential oils to the tobacco cutworm, Spodoptera litura. Fitoterapia 72: 65-68.
55. Jamwal,, Bhattacharya, S. and Puri, S. 2018. Plant growth regulator mediated consequences of secondary metabolites in medicinal plants. Journal of Applied Research on Medical and Aromatic Plants 9:26–38.
56. Javier, A.M.V., Ocampo, V.R., Ceballo, F.A. and Javier, P.A. 2017. Insecticidal activity of selected oil extracts against common cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae). Philippine Journal of Science 146: 247-256.
57. Jeyasankar, A., Premalatha, S. and Elumalai, K. 2012. Biological activities of Solanum pseudocapsicum (Solanaceae) against cotton bollworm, Helicoverpa armigera Hübner and armyworm, Spodoptera litura Fabricius (Lepidotera: Noctuidae). Asian Pasific Journal of Tropical Biomedicine 2: 981-986.
58. Jeyasankar, A., Raja, N. and Ignacimuthu, S. 2011. Insecticidal compound isolated from Syzygium lineare Wall. (Myrtaceae) against Spodoptera litura (Lepidoptera: Noctuidae). Saudi Journal of Biological Sciences 18: 329-332.
59. Jia, Q., Zeng, H., Zhang, J., Gao, S., Xiao, N., Tang, J., Dong, X. and Xie, W. 2021. The crystal structure of the Spodoptera litura chemosensory protein CSP8. Insects 12: 602.
60. Kamaraj, C., Gandhi, P.R., Elango, G., Karthi, S., Chung, I.M. and Rajakumar, G. 2018. Novel and environmental friendly approach; Impact of Neem (Azadirachta indica) gum nano formulation (NGNF) on Helicoverpa armigera (Hub.) and Spodoptera litura (Fab.). International Journal of Biological Macromolecules 107: 59-69.
61. Kamaraj, C., Rahuman, A.A. and Bagavan, A. 2008. Antifeedant and larvicidal effects of plant extracts against Spodoptera litura (F.), Aedes aegypti L. and Culex quinquefasciatus Say. Parasitology Research 103: 325-331.
62. Kang, K., Cai, Y., Yue, L. and Zhang, W. 2021. Effects of different nutritional conditions on the growth and reproduction of Nilaparvata lugens (Stål). Frontiers in Physiology 12:794721.
63. Kranz, J., Schumutterer, and Koch. W. eds. 1977. Diseases pests and weeds in tropical crops. Berlin and Hamburg, Germany: Verlag Paul Parley.
64. Kortbeek, R.W., van der Gragt, M. and Bleeker, P.M. 2018. Endogenous plant metabolites against insects. European Journal of Plant Pathology 154: 67-90.
65. Koul, O., Jain, M.P. and Sharma, V.K. 2000. Growth inhibitory and antifeedant activity of extracts from Melia dubia to Spodoptera litura and Helicoverpa armigera larvae. Indian Journal of Experimental Biology 38: 63-68.
66. Koul, O., Singh, R., Kaur, B. and Kanda, D. 2013. Comparative study on the behavioral response and acute toxicity of some essential oil compounds and their binary mixtures to larvae of Helicoverpa armigera, Spodoptera litura and Chilo partellus. Industrial Crops and Products 49: 428-436.
67. Kousar, B., Bano, A. and Khan, N. 2020. PGPR modulation of secondary metabolites in tomato infested with Spodoptera litura. Agronomy 10: 778.
68. Lajide, L., Escoubas, P. and Mizutani, J. 1993. Antifeedant activity of metabolites of Aristolochia albida against the tobacco cutworm, Spodoptera litura. Journal of Agricultural and Food Chemistry 41: 669-673.
69. Lee, K.P. 2010. Sex-specific differences in nutrient regulation in a capital breeding caterpillar, Spodoptera litura (Fabricius) 56: 1685-1695.
70. Lin, T., Chen, X., Li, B., Chen, P., Guo, M., Zhou, X., Zhong, S., Cheng, 2019. Geographical origin identification of Spodoptera litura (Lepidoptera: Noctuidae) based on trace element profiles using tobacco as intermedium planted on soils from five different regions. Microchemical Journal 146: 49–55.
71. Ling, R., Yang, R., Li, P., Zhang, X., Shen, T., Li, X., Yang, Q., Sun, L. and Yan, J. 2019. Asatone and Isoasatone A against Spodoptera litura by acting on cytochrome P450 Monoxygenases and Glutathione Transferases. Molecules 24: 3940.
72. Ling, S., Zhao, Y., Sun, S., Zheng, D., Sun, X., Zeng, R., Chen, D. and Song, Y. 2022. Enhanced anti-herbivore defense of tomato plants against Spodoptera litura by their rhizosphere bacteria. BMC Plant Biology 22: 254.
73. Liu, J., Hua, J., Qu, B., Guo, X., Wang, Y., Shao, M. and Luo, S. 2021. Insecticidal terpenes from the essential oils of Artemisia nakaii and their inhibitory effects on acetylcholinesterase. Frontiers in Plant Science 12: 720816.
74. Mahajan, E., Singh, S., Diksha Kaur, S. and Sohal, S.K. The genotoxic, cytotoxic and growth regulatory effects of plant secondary metabolite β-caryophyllene on polyphagous pest Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) Toxicon 219: 106930.
75. Malarvannan, S., Giridharan, R., Sekar, S., Vaiyapuri, P.R. and Nair, Sudha. 2008. Bioefficacy of crude and fraction of Argemone mexicana against tobacco caterpillar, Spodoptera litura Fab. (Noctuidae: Lepidoptera). Journal of Biopesticides 1: 55-62.
76. Mamat, M.J. and Soon, L.G. 1982. The biology and control of some common lepidopteran pests of Virginia tobacco. MARDI Research Bulletin 9: 17-31.
77. Mitra, S., Firake, D.M., Umesh, K.P., Pandey, P.P. and Pandit, S. 2021. Polyphagous caterpillars of Spodoptera litura switch from trap crop to the main crop, improve fitness, and shorten generation time. Journal of Pest Science 94: 1091-1103.
78. Murfadunnisa, S., Vasantha-Srinivasan, P., Ganesan, R., Senthil-Nathan, S., Tae-Jin, K., Ponsakar, A., Kumar, S.D., Chandramohan, D. and Krutmuang, P. 2019. Larvicidal and enzyme inhibition of essential oil from Spheranthus amaranthroids (Burm.) against lepidopteran pest Spodoptera litura (Fab.) and their impact on non-target earthworms. Biocatalysis and Agricultural Biotechnology 21: 101324.
79. Morimoto, M., Tanimoto, K., Sakatani, A. and Komai, K. 2002. Antifeedant activity of an anthraquinone aldehyde in Galium aparine L. against Spodoptera litura F. Phytochemistry 60: 163-166.
80. Navasero, M.V. and Navasero, M.M.. 2003. Potential of farm-level production and utilization of Spodoptera litura nucelopolyhedrosis virus. Philippine Enomologistt 17: 179–182.
81. Natikar, P.K. and Balikai, R.A. 2017. Present status on bio-ecology and management of tobacco caterpillar, Spodoptera litura (Fabricius). International Journal of Plant Protection 10: 193-202.
82. Okolle, J.N., Mashhor, M. and Abu Hassan, A. 2006. Folivorous insect fauna on two banana cultivars and their association with non-banana plants. Jurnal Biosains 17: 89-101.
83. Parry, D. and McCullough, D.G. 2004. Foliage feeders in temperate and boreal forests. Encyclopedia of Forest Sciences :107–112.
84. Pavunraj, M., Baskar, K. and Ignacimuthu, S. 2012. Efficacy of Melochia corchorifolia L. (Sterculiaceae) on feeding behavior of four lepidopteran pests. International Journal of Agricultural Research 7: 58-68.
85. Pavunraj, M., Ezhumalai, P., Nagarajan, K., Murali, P. and Rajeshkumar. S. 2024. Biopesticidal potential of Lippia Javanica (Burm. F) Spreng. leaf extracts and their fractions against Spodoptera Litura (Fab.). Uttar Pradesh Journal of Zoology 45: 245-254.
86. Pavunraj, M., Muthu, C., Ignacimuthu, S., Janarthanan, S., Duraipandiyan, V., Raja, N. and Vimalraj, S. 2011. Antifeedant activity of a novel 6-(4,7-hydroxy-heptyl) quinone (A (R)) from the leaves of the milkweed Pergularia daemia on the cotton bollworm Helicoverpa armigera (Hub.) and the tobacco armyworm Spodoptera litura (Fab.). Phytoparasitica 39: 145-150.
87. Pavunraj, M., Paulraj, M.G., Sivagnanam, S.K. Rao, M.R.K. and Ignacimuthu, S. 2012. Feeding deterrence, larvicidal and haemolymph protein profiles of an Indian traditional medicinal plant Alangium salviifolium (L.F.) Wangerin on cluster caterpillar, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Archives of Phytopathology and Plant Protection 45: 2066-2075.
88. Pavunraj, M., Subramanian, K., Muthu, C., Seenivasan, S.P., Duraipandiyan, V., Pakiam, S.M. and Ignacimuthu S. 2006. Bioefficay of Excoecaria agallocha (L.) leaf extract against the armyworm Spodoptera litura (Fab.) (Lepidoptera: Noctuidae). Entomon 31:37–40.
89. Ponsankar, A., Sahayaraj, K., Senthil-Nathan, S., Vasantha-Srinivasan, P., Karthi, S., Thanigaivel, A., Petchidurai, G., Madasamy, M. and Hunter, W.B. 2020. Toxicity and developmental effect of cucurbitacin E from Citrullus colocynthis L. (Cucurbitales: Cucurbitaceae) against Spodoptera litura Fab. and a non-target earthworm Eisenia fetida Savigny. Environmnetal Science and Pollution Research 27: 23390-23401.
90. Ponsankar, A., Vasantha-Srinivasan, P., Senthil-Nathan, S., Thanigaivel, A., Edwin, E.S., Selin-Rani, S., Kalaivani, K., Hunter, W.B., Alessandro, R.T., Abdel-Megeed, A., Paik, C.H., Duraipandiyan, V. and Al-Dhabi, N.A. 2016. Target and non-target toxicity of botanical insecticide derived from Couroupita guianensis L. flower against generalist herbivore, Spodoptera litura Fab. and an earthworm, Eisenia foetida Savigny. Ecotoxicology and Environmental Safety 133: 260-270.
91. Prajapati, V.K., Varma, M. and Vadassery, J. 2020. In silico identification of effector proteins from generalist herbivore Spodoptera litura. BMC Genomics 21: 819.
92. Punia, A., Chauhan, N.S., Singh, D., Kesavan, A.K., Kaur, S. and Sohal, S.K. 2021 Effect of gallic acid on the larvae of Spodoptera litura and its parasitoid Bracon hebetor. Scientific Reports 11: 531.
93. Raja, N., Jeyasankar, A., Jeyakumar, V. and Ignacimuthu, S. 2005. Efficacy of Hyptis suaveolens against lepidopteran pest. Current Science 88: 220-222.
94. Rahman, S.M., Vijayalakshmi, K., Rani, C.V.D., Basha, S.A. and Srinivas, C. 2021. Survey on major insect pests of groundnut in Southern Telangana zone. The Pharma Innovation Journal SP-10: 291-296.
95. Raja, N., Elumalai, K., Jayakumar, M., Jeyasankar, A., Muthu, C. and Ignacimuthu, S. 2003. Biological activity of different plant extracts against armyworm, Spodoptera litura (Fab) (Lepidoptera: Noctuidae). Journal of Entomological Research 27: 281-292.
96. Rao, D.E., Divya, K., Prathyusha, I.V.S.N. Krishna, C.R. and Chaitanya, K.V. Insect-resistant plants. Current Developments in Biotechnology and Bioengineering 15: 47–74.
97. Rao, N.V., Maheswari, T.U., and Manjula, 2005. Review on Botanical Pesticides as Tools of Pest Management. New Delhi: Narosa Publishing House Pvt. Ltd. p. 1–16.
98. Ruttanaphan, T., Pluempanupat, W., Aungsirisawat, C., Boonyarit, P., Goff, G.L. and Bullangpoti, V. 2019. Effect of plant essential oils and their major constituents on cypermethrin tolerance associated detoxification enzyme activities in Spodoptera litura (Lepidoptera: Noctuidae). Journal of Economic Entomology 112: 2167-2176.
99. Ruttanaphan, T., Songoen, W., Pluempanupat, W. and Bullangpoti, V. 2023. Potential insecticidal extracts from Artocarpus lacucha against Spodoptera litura (Lepidoptera: Noctuidae) larvae. Journal of Economic Entomology 116: 1205-1210.
100. Sabir, N. and Singh, B. 2013. Protected cultivation of vegetables in global arena: A review. Indian Journal of Agricultural Sciences 83: 123-135.
101. Safder, A., Afzal, Z., Munawar, F., Hashmi, A.M., Ali, R.B. and Amanat, N. 2022. Efficacy of botanicals extracts against Spodoptera litura (Lepidoptera: Noctuidae) under laboratory . Journal of Scientific Agriculture 6: 32-35.
102. Selin-Rani S., Senthil-Nathan S., Thanigaivel A., Vasantha-Srinivasan P., Edwin E.S., Ponsankar A., Lija-Escaline J., Kalaivani K., Abdel-Megeed A., Hunter W.B. and Alessandro, R.T. 2016. Toxicity and physiological effect of quercetin on generalist herbivore, Spodoptera litura and a non-target earthworm Eisenia fetida Savigny. Chemosphere 165:257–267.
103. Shah, T.H. 2017. Plant nutrients and insects development. International Journal of Entomology Research 2: 54-57.
104. Sharma, H.C. Dhillon, K. and Sahrawat, K.L. 2012.Botanical Pesticides: Environmental Impact. In: Environmental Safety of Biotech and Conventional IPM Technologies. Studium Press LLC, Texas, USA, pp. 159-190.
105. Shivankar, S.B., Magar, S.B., Shinde, V.D., Ghodake, P.V., Yadav, R.G. and Patil, A.S. 2008. Role of avian community in reduction of Spodoptera pest population in sugar beet at Pune. Our Nature 6: 19-25.
106. Spiteller, D., Oldham, N.J., Boland, W. 2004. N-(17-Phosphonooxylinolenoyl)glutamine and N-(17-phosphonooxylinoleoyl)glutamine from insect gut: the first backbone-phosphorylated fatty acid derivatives in nature. The Journal of Organic Chemistry 69: 1104-1109.
107. Su, Q., Zhou, Z., Zhang, J., Shi, C., Zhang, G., Jin, Z., Wang, W. and Li, C. 2017. Effect of plant secondary metabolites on common cutworm, Spodoptera litura (Lepidoptera: Noctuidae). Entomological Research 48: 18-26.
108. Sugijanto, E., and Dorra, B.L. 2016. Antimicrobial activity of Cladosporium oxysporum endophytic fungus extract isolated from Aglaia odorata Lour. Indonesian Journal of Medicine 2: 108–115.
109. Sun, H., Blanford, S., Guo, Y., Fu, X. and Shi, W. 2012. Toxicity and influences of the alkaloids from Cynanchum komarovii Al. Iljinski (Asclepiadaceae)on growth and cuticle components of Spodoptera litura Fabricius (Noctuidae) larvae. Nature Product Research 26: 903-912.
110. Sundar, N.S., Karthi, S., Sivanesh, H., Stanley-Raja, V., Chanthini, K.M., Ramasubramanian, R., Ramkumar, G., Ponsankar, A., Narayanan, K.R., Vasantha-Srinivasan, P., Alkahtani, J., Alwahibi, M.S., Hunter, W.B., Senthil-Nathan, S., Patcharin, K., Abdel-Megeed, A., Shawer, R. and Ghaith. A.2021. Efficacy of Precocene I from Desmosstachya bipinnata as an effective bioactive molecules against the Spodoptera litura and its impact on Eisenia fetida Savigny. Molecules 26: 6384.
111. Sushilkumar and Ray P.20Host plant preference of army worm (Spodoptera litura) on crops and weeds. Indian Journal of Weed Science 50:100–102.
112. Tojo S., Ryuda M., Fukuda T., Matsunaga T., Choi D. and Otuka A. Overseas migration of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae), from May to mid-July in East Asia. Applied Entomology and Zoology 48:131–140.
113. Tong, H., Su, Q., Zhou, X. and Bai, L. 2004. Field resistance of Spodoptera litura (Lepidoptera: Noctuidae) to organophosphates, pyrethroids, carbamates and four newer chemistry insecticides in Hunan, China. Journal of Pest Science 86: 599-609.
114. Tu, Y.G., Wu, K., Xu, F.S. and Lu, Y.H. 2009. Laboratory evaluation of flight activity of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae). Insect Science 17: 53-59.
115. Udebuani, A., Abara, P., Obasi, K. and Okuh, S. 2015. Studies on the insecticidal properties of Chromolaena odorata (Asteraceae) against adult stage of Periplaneta americana. Journal of Entomology and Zoology Studies 3: 318–321.
116. Vasantha-Srinivasan, P., Senthil-Nathan, S., Thanigaivel, A., Edwin, E., Ponsankar, A., Selin-Rani, S., Pradeepa, V., Sakthi-Bhagavathy, M., Kalaivani, K., Hunter, W.B., Duraipandiyan, V. and Al-Dhabi, N. 2016. Developmental response of Spodoptera litura (Fab.) to treatments of crude volatile oil from Piper betle L. and evaluation of toxicity to earthworm, Eudrilus eugeniae Kinb. Chemosphere 155:336–347.
117. Vasantha-Srinivasan, P., Shanmuga-Priya, S., Han, Y.S., Radhakrishnan, N., Amala, K., Karthi, S. and Senthil-Nathan, S. 2023. Insecticidal activities of two fig tree leaf extracts against the cotton pest Spodoptera litura (Fab.) and their impact on the non-target red worm Eisenia foetida (Savigny). Entomological Research 53: 485-508.
118. Vasantha-Srinivasan, P., Unni, P.K.S., Karthi, S., Ganesan, R., Senthil-Nathan, S. Chellappandian, M., Radhakrishnan, N. and Rajagopal, R. 2024. Bio-efficacy of chloroform crude extracts of chick weed Ageratum conyzoides (Linn.) against the tobacco cutworm Spodoptera litura (Linn.) and their non-toxicity against the beneficial earthworm. Journal of King Saud University – Science 36: 102930.
119. Vashisth, S., Chandel, Y.S. and Kumar, S. 2012. Biology and damage potential of Spodoptera litura Fabricius on some important greenhouse crops. Journal of Insect Science 25: 150-154.
120. Vengateswari, G., Arunthirumeni, M. and Shivakumar, S. 2020. Effect of food plants on Spodoptera litura (Lepidoptera: Noctuidae) larvae immune and antioxidant properties in response to Bacillus thuringiensis infection. Toxicology Reports 7: 1428-1437.
121. War, A.R., Buhroo, A.A., Hussain, B., Ahmad, T., Nair, R.M. and Sharma, H.C. 2020. Plant Defense and Insect Adaptation with Reference to Secondary Metabolites. In: Mérillon, J.M. and Ramawat, K., Eds., Co-Evolution of Secondary Metabolites, Reference Series in Phytochemistry, Springer, Cham, Switzerland, 1-28.
122. War, A.R., Paulraj, M.G., Ahmad, T., Buhroo, A.A., Hussain, B., Ignacimuthu, S. and Sharma, H.C. 2012. Mechanisms of plant defense against insect herbivores. Plant Signaling & Behavior 7: 1306-1320.
123. Xia, T., Liu, Y., Lu, Z and Yu, H. 2023. Natural coumarin shows toxicity to Spodoptera litura by inhibiting detoxification enzymes and glycometabolism. International Journal of Molecular Sciences 24: 13177.
124. Xia, X., Lan, B., Tao, X., Lin, J. and You, M. 2020. Characterization of Spodoptera litura gut bacteria and their role in feeding an growth of the host. Frontiers in Microbiology 11: 1492.
125. Xue, M., Pang, Y.H., Wang, H.T., Li, Q.L. and Liu, T.X. 2010. Effects of four host plants on biology and food utilization of the cutworm, Spodoptera litura. Journal of Insect Science 10: 22.
126. Ye, L.M., Di, X.Y., Yan, B., Liu, J.F., Wang, X.Q. and Yang, M.F. 2022. Population parameters an feeding preferences of Spodoptera litura (Lepidoptera: Noctuidae) on different Asparagus officinalis tisssues. Insects 13: 1149.
127. Zhang, J., Li, S., Li, W., Chen, Z., Guo, H., Liu, J., Xu, Y., Xiao, Y., Zhang, L., Arunkumar, K.P., Smagghe, G., Xia, Q., Goldsmith, M.R., Takeda, M. and Mita, K. 2021. Circadian regulation of night feeding and daytime detoxification in a formidable Asian pest Spodoptera litura. communications biology 4: Article Number 286.