Geographic variation in diapause induction and termination of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae).

Highlights: [•] The critical photoperiod for diapause induction was positively related to latitude. [•] Diapause duration was longer in northern populations at high temperatures. [•] Diapause duration was negatively correlated with latitude under natural conditions. [•] Diapause-inducing temperature on diapause duration had a significant effect. [•] Response of southern and northern populations to chilling was different. [ABSTRACT FROM AUTHOR]