<div>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.&nbsp; 
 
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&rsquo; (BBP&rsquo;s) viz., avidin and streptavidin in comparison with spinosad by pellet feeding method. Similarly the effect of BBP&rsquo;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 &ge; 75 ppm was found effective by recording lesser number of eggs (&le; 9 eggs), delayed day of first adult emergence (&ge; 53 days), maximum development period (&gt; 68 days), minimum adult emergence (&le; 13%), lower growth index (&le; 0.2) and minimum weight loss (&le; 16%) and streptavidin at concentrations of &ge; 75 ppm recorded comparatively minimum eggs (&le; 7 eggs), prolonged day of first adult emergence (&ge; 66 days), maximum development period (&ge; 82 days), minimum adult emergence (&le; 13%), lower growth index of &le; 0.16 and minimum pellet weight loss of &le; 12% respectively.</div>

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

This study aimed to reveal the distribution and morphological characteristics of vasoactive intestinal peptide (VIP) at different ages in the bursa of &nbsp;Fabricius (BF) in Chinese Yellow Quail. The distribution and morphological characteristics of VIP of &nbsp;BF in Chinese yellow quails at different ages (0, 1, 3, 5, 9, 13, 17, 21, 25, 29, 32 and 36 weeks) were observed using the immunohistochemical streptavidin-biotin complex method after obtaining the sections and subsequent immunohistochemical staining. Then semi-quantitative analysis of the mean optical density (MOD), integral optical density (IOD) and mean gray value (MGV) for VIP immunoreactivity was performed through Image-Pro Plus 6.0 software. VIP was observed at all ages in Chinese yellow quail&rsquo;s BF. It formed a long fusiform, oval or granular type structures with clear outline mainly localized in the submucosa, muscular layer and serosal connective tissue. At 25 weeks of age, the MOD value of VIP-positive cells reached the maximum, and then gradually reduced, while the MGV value was the lowest. We observed the localization and morphological characteristics of VIP in BF of Chinese yellow quail. VIP was mainly localized in the submucosa, muscular layer and serosal connective tissue of BF. Findings of this study may provide further understanding of the function of VIP in BF of Chinese yellow quails.

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

Immunohistochemical localization of vasoactive intestinal peptide in bursa of fabricius of Chinese yellow quail

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