Growth Rate and Thigmotactic Behavior of Turkestan Cockroach (Blatta lateralis) Under Different Illumination Conditions

Growth Rate and Thigmotactic Behavior of Turkestan Cockroach (Blatta lateralis) Under Different Illumination Conditions

 Jenelyn R. Agua, Kathlyn Shyne N. Crausos, & Jemavelle Mie L. Sasam
Biology Program, Math and Science Department, College of Arts and Sciences Education, DPT Building, University of Mindanao, Matina, Davao City, Philippines
DOI: https://doi.org/10.51584/IJRIAS.2023.8714
Received: 10 June 2023; Accepted: 29 June 2023; Published: 03 August 2023

Abstract: Insects, including cricket, fly, locust, and cockroach species, exhibit growth and escape (thigmotactic) responses to aversive stimuli. This study aimed to investigate the growth rate and thigmotactic behavior of Turkestan cockroaches (Blatta lateralis) under different illumination conditions: natural (direct) sunlight, artificial white light, and dark control in Davao City, Philippines. In this study, gentle agitation of the container (i.e., wind puffs and food drops during feeding) stimuli stimulated B. lateralis, and the more they are exposed to natural (direct) sunlight and other bright displays, the lesser they survive, and their growths are. Thigmotaxis and body length were measured weekly starting on the 5th week of observation, utilizing the six experimentally nymphal organisms as subjects starting with 1.1 cm in size each organism to a 7″ x 55″ container with the 20 cm x 28 cm paper shelters folded within a 10° angle in a room with direct sunlight, a dark edge, and floor lit by a 60-W light bulb with 1 inch above the center of the container, and plain darkness. The results demonstrated that the organism’s selection from a finite set of preferred escape trajectories (ETs) could cause variation in ETs where overall thigmotactic stimuli response was higher and had the largest growth with a body length of 2.05 cm for nymphs placed under artificial white light. In conclusion, Turkestan cockroaches exhibited flight responses even to impending and particularly gentle agitation stimuli and had a more dark or natural light condition survival rate.
Keywords: Turkestan cockroach, Blatta lateralis, nymphs, Davao City, thigmotaxis, growth rate, illumination

I. Introduction

Turkestan Cockroach (Blatta lateralis) is a significant invasive species that inhabit inground containers in urban areas [1] and is considered a household pest along clay floors [2]. They are native to Central Asia [3] and India [4], occasionally inhabiting the indoors but primarily thriving on piles of dung in garden soils [5]. Their dispersal has been widely associated with human commerce and movement [6] and also served as significant models in numerous disciplines, including neurology and chemical ecology [7]. Despite their invasiveness and habitation across peridomestic areas, there is limited information on strategies for managing these pests [8]. Moreover, despite their known popularity among reptile breeders and availability for marketing (both online and traditional markets), there is scarce information regarding their biology [1] and comparative data on cockroach mating and behavioral patterns are the most extensive [7].

In California, cockroaches are the most chronic and problematic species, living and breeding in indoor sites linked with food preparation, causing health risks owing to food contamination and indoor allergen generation. Cockroaches feed on garbage, rotting food, and feces, allowing them to become vectors of diseases through infecting surfaces and leaving droppings that contain pathogenic microorganisms; partnered with the nocturnal habits that make them ideal carriers of microbes [9]. That aside, they can become a nuisance in schools, homes, hospitals, restaurants, warehouses, apartments, and nearly any other building with food processing or storage capabilities. They spoil food and dining utensils, damage the fabric and compostable bags, and leave surfaces with stains and foul odors [10].

The mentioned impression elucidates that the cockroach’s demand for food, water, and refuge from potential predators and unfavorable microclimate significantly impacts its behavior and longevity [11]. The adult B. lateralis is three cm tall, with females shorter than males. Female B. lateralis generate between two and twenty-five ootheca, or egg capsules, in their lifecycle. Each ootheca has approximately 18 eggs. The species matures after five molts, and the nymphal development period at 26.7°C is around 224 days. It takes roughly three years for five generations of Turkestan cockroaches to mature [1].