Diversity, distribution and seasonal prevalence of cockroach species in urban environments of Dhaka, Bangladesh

Abstract

Cockroaches are common urban pests in tropical regions, posing considerable economic and health threats by transmitting microbes, allergens, and a range of disease-causing pathogens. To study the diversity of cockroach species, a total of 1186 samples were collected from households, hospitals and outdoor environments of Dhaka, the capital city of Bangladesh. Based on standard morphological keys, a total of eight cockroach species were identified- Periplaneta americana, P. brunnea, P. australasiae, Blatella germanica, Hebardina concinna, Pycnoscelus surinamensis, Balta notulata and Blaberidae sp. Residential areas and hospitals were infested by P. americana, P. brunnea, P. australasiae, B. germanica, H. concinna, Pyc. surinamensis. Two species, B. notulata and Blaberidae sp. were found in environmental field areas only. Residential regions and hospitals had excessive infestations of Blattella germanica, followed by Periplaneta americana. B. germanica was the most dominant indoor species with highest diversity indices (2.86) in study areas. The seasonal prevalence of cockroach species was notable, with 45% of specimens collected during the summer, 43% during the monsoon, and only 12% in the winter. The prevalence of various cockroach species is affected by factors such as the availability of food, hygiene standards, and environmental conditions. Effective control strategies require a clear understanding of their biological characteristics and behaviors, strengthened sanitation practices, and the careful, strategic use of commercial insecticides.