Effects of High Temperature on Lifespan, Fecundity, and Protective Enzymes of Ectropis grisescens

  Objective  Resistance and response to high temperatures of the antioxidants in Ectropis grisescens were studied.

  Method  Lifespan and fecundity of adult E. grisescens Warren after being exposed to 30 ℃, 35 ℃, 38 ℃ or 41 ℃ for 1 h or 44 ℃ for 3 min were observed according to measurements on the egg hatchability and total protein content and activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) as well as total antioxidant capacity (T-AOC) in the insects.

  Result   The increased temperature significantly shortened the lifespan, decreased the female oviposition, and lowered the egg hatchability of E. grisescens. At 41 ℃ and 44 ℃, the egg ceased to hatch. The maximum total protein contents in the female and male adults differed significantly under different temperatures—it was under 35 ℃ for the females and 38 ℃ for the males. The SOD activity in the female adults changed in an upside-down V pattern as the temperature rose, while that in the male adults was low at 41 ℃. In the female adults the highest CAT activity occurred at 44 ℃, the T-AOC decreased with increasing temperature, and the POD rose with rising temperature, whereas those in the male adults exhibited a low-high-low trend in the temperature range.

  Conclusion  The protective enzymes in E. grisescens Warren played a key role in how the insect adapted to high temperature stress.