Effects of neuropeptide F2 on female reproduction in the cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae)

Abstract

Recently, neuropeptide F2 (NPF2) has been demonstrated to increase food consumption and body weight in the cotton bollworm, Helicoverpa armigera. This study evaluated the effect of NPF2 on the adult female reproductive system of H. armigera. Daily NPF2 injections increased oocyte size, ecdysteroid titre in ovaries and haemolymph and the expression level of ecdysone receptor (EcR), ultraspiracle (USP) and vitellogenin (Vg) genes. However, NPF2 injection had no effect on the expression level of hormone receptor 3 (HR3). Fecundity and fertility were increased after the injection of NPF2. The knockdown of the NPF2 gene using RNA interference (RNAi) had opposite effects compared to NPF2 injection. Overall, these results revealed that NPF2 has a regulatory role in the female reproduction of the cotton bollworm.