The diamondback moth, Plutella xylostella (Lepidoptera, Plutellidae), is one of the most destructive pests attacking economically important Brassicea crops.Currently, there are still no effective strategies to control this very prolific insect that can reproduce rapidly in China.To better understand the reproductive regulation of P xylostella and the consequences on reproductive potential and adaptability, we proposed to examine the role of vitellogenin gene Vg (PxVg) in P xylostella, which is the fundamental substance of reproductive regulation in insects.