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

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.