Relative humidity affects life table parameters of Callosobruchus maculatus (Fabricius) (Coleoptera:Bruchidae)

Dried seeds of pigeonpea, Cajanus cajan are frequently attacked by a range of insect pests of which Callosobruchus maculatus is the most serious, causing significant loss in post-harvest storage facilities. An experiment was designed to determine the effect of relative humidity on fecundity life table parameters of C. maculatus (Trinidad strain). Age related mortality and fecundity curves for C. maculatus derived in the present study were typical of "r" selected organisms. R-0 exhibited a positive correlation with relative humidity ranging from 15.29 at 29.5%RH to 252.17 at 75.5% RH. Maximum longevity for both males and females occurred at 75.5%RH being positively correlated with relative humidity for both sexes. Fifty percent oviposition occurred at humidity of 50.5% > 63.0%> 75.5%>29.5%. The finite rate of increase (lambda) for all the relative humidities in the current study was always > 1 indicating an increasing population and was highest at 75.5% RH.