Effects of azadirachtin on the development and gene expression of fifth instar larvae of Indianmeal moth, Plodia interpunctella

The effects of azadirachtin on the rates of pupation, adult eclosion, and the expression of nine selected genes were evaluated in Plodia interpunctella. The newly molted fifth instar larvae (V0) were fed a pollen diet containing different amounts of azadirachtin. When larvae ingested azadirachtin at 1 and 10 ppm, pupation was 85 and 75.8%, respectively, and adult eclosion was 81.7 and 55.3%, respectively. The effects of azadirachtin on gene expression were analyzed using real-time RT-PCR analysis. When V0 larvae ingested azadirachtin for 2 days, expression of some genes related to development, stress, and immunity was affected by azadirachtin. mRNA levels of shsp, hsp90, ecdysone receptor, ultraspiracle, prophenoloxidase and hemolin were upregulated, although both ultraspiracle and hemolin were downregulated at higher doses. Levels of hsc70, hsp70 and beta-1,3-glucan recognition protein were not changed. Overall, azadirachtin significantly inhibited post-embryonic development and differentially modulated gene expression patterns of P. interpunctella. (C) Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2011. Published by Elsevier B.V. All rights reserved.