Effect of short-term exposure to high temperatures on reproductive behaviors and physiological enzyme activities in Zeugodacus tau

Abstract

Zeugodacus tau is an economically important invasive pest of various vegetables and fruits. The present study evaluated the effects of short-term (12 h) exposure to high temperatures on the reproductive behaviors and physiological enzyme activities of Z. tau insects. It was observed that the mating rate in the treatment group increased significantly at temperatures of 34 °C and 38 °C compared to the control. The highest mating rate of the control♀-treatment♂ mating was 60.00%, which occurred at 34 °C, while no mating occurred until 24 h, at 42 °C. Moreover, the short-term application of high temperatures reduced the pre-mating period and prolonged the duration of copulation. The treatment♀-treatment♂ mating had the shortest pre-mating period of 39.00 min and the longest copulation duration of 678.00 min at 38 °C. Mating after the short-term application of high temperature exerted adverse effects on the reproduction of females, while mating with males exposed at 34 °C and 38 °C significantly increased female fecundity. At 40 °C, the treatment♀-control♂ mating presented the lowest fecundity and hatching rate of 293.25 eggs and 25.71%, respectively. The control♀-treatment♂ presented the highest fecundity of 1016.75 eggs at 38 °C. Furthermore, the SOD, POD, and CAT activities exhibited significant changes (increase or decrease) after the short-term exposure of insects to high temperatures. The SOD activity changed the most at 38 °C, with the females and males exhibiting 3.64 times and 3.10 times the SOD activity, respectively, compared to control. The AchE, CarE, and GST activities first increased and then decreased with the increase in temperature. The CarE activity changed the most at 38 °C, with the females and males exhibiting 7.81 times and 1.69 times increased activities, respectively. In conclusion, mating strategy and physiological stress are important adaptive mechanisms of Z. tau under short-term heat stress, and the adaptation is sex-specificity.