Effects of short-term heat shock of eggs on the development and fecundity of Plutella xylostella (L.) (Lepidoptera: Plutellidae)

It has been hypothesized that the survival, development, fecundity and even population expansion of insects are all affected significantly by extremely high temperature. The diamondback moth, Plutella xylostell (L.) (Lepidoptera: Plutellidae), is a serious and economically important pest of cruciferous crops throughout the word. In this research, the adult longevity and fecundity of P. xylostella were studied. After effect of heat shock stress, (30, 35 and 40 °C) for 2, 4, 6 and 8h, the experiments were conducted at 25±1 °C, 65±5% RH, and a photoperiod of 16:8 (L:D)h on Brassica napus. The developmental time of immature stages were significantly affected after heat shock temperatures (30 to 40 °C) when compared to the 25 °C control, but the developmental time of larvae did not differ significantly at 40 °C. The pupal development time differed significantly at heat shock temperatures, which the longest (6.13±0.05 days) at 30 °C for 2h. Heat shock temperature also had significant impact on adult longevity and fecundity of diamondback moth. The longest adult longevity for females and males was determined to be 14.47±1.04 and 11.04±0.95 respectively at 35 °C for 2h. The fecundity of females fluctuated significantly with increasing temperature stress. Our findings can be used to develop a more profound understanding on the potential for this insect to evolve in response to environmental temperature changes.