Biotin Inhibitors, Avidin and Streptavidin: Their Influence on Lethality, Growth and Survival of Callasobruchus maculatus (Chrysomelidae: Coleoptera)

Background: C. maculatus, the most important and cosmopolitan pest, severely attacking several stored pulses leading to weight loss, market value, as well as the germination potential of the infested grains. The present study was conducted to know the effect of biotin inhibitors, avidin and streptavidin on lethality, growth and survival of Callasobruchus maculatus. Methods: The experiment was conducted in the laboratory of Department of Entomology, Agricultural College, Bapatla during 2017-18. Bio assays were conducted against C. maculatus with biotin binding proteins’ (BBP’s) viz., avidin and streptavidin in comparison with spinosad by pellet feeding method. Similarly the effect of BBP’s on growth development of C. maculatus was also studied. Result: Based on bioassay studies, the LC50 for avidin and streptavidin were 14.733 and 11.192 ppm while LC90 was 76.031 and 86.134 ppm, respectively. The growth and development of C. maculatus was studied at approximately the respective LC25, LC50, LC75, LC80 and LC90 values of avidin and streptavidin. Avidin and streptavidin incorporated pellets when fed to it, avidin at concentration of ≥ 75 ppm was found effective by recording lesser number of eggs (≤ 9 eggs), delayed day of first adult emergence (≥ 53 days), maximum development period ( greater than 68 days), minimum adult emergence (≤ 13%), lower growth index (≤ 0.2) and minimum weight loss (≤ 16%) and streptavidin at concentrations of ≥ 75 ppm recorded comparatively minimum eggs (≤ 7 eggs), prolonged day of first adult emergence (≥ 66 days), maximum development period (≥ 82 days), minimum adult emergence (≤ 13%), lower growth index of ≤ 0.16 and minimum pellet weight loss of ≤ 12% respectively.