Diversity and Distribution of Callosobruchus spp. Attacking Stored Chickpea in Northern Tracts of West Bengal

Diversity of stored grain insects is often neglected, as many researchers and consumers think that it has a limited or no diversity as the consumer tolerance towards insect’s pest in stored grains is zero. In this context a survey was conducted in three districts i.e., Coochbehar, Alipurduar and Jalpaiguri districts of northern tracts of West Bengal to find the diversity of species of pulse beetle and its species abundance in stored chickpea during 2018-2020. In the collected chickpea seed samples, four species namely, Callosobruchus chinensis L., C. maculatus F., C. analis L. and Callosobruchus sp. (indet) unknown were observed. Coochbehar districts had highest diversity with species evenness (0.49), Brillouin index (1.17), Simpsons index (0.68), Shannon index (1.23), Hill index (0.49) and effective diversity (3.43) followed by Jalpaiguri with Species evenness (0.46), Brillouin index (1.04), Simpson index (0.64), Shannon index (1.09), hill index (0.48) and Effective diversity (2.99). Alipurduar district found lowest species diversity indices. Community structure of Callosobruchus spp. in three districts follows Null model which found as best fit model. It is inferred from the study that the northern tracts of West Bengal four species of pulse beetles are prevailing and further study needs to be undertaken for any strain variation of the pulse beetle in these areas.