关键词: 莲草直胸跳甲, 空心莲子草, 高温暴露, 生殖力, 寿命, 羽化率, 生物防治

Abstract: In this study, the longevity, reproduction and survival rate of Agasicles hygrophila adults under different high temperatures (37, 39, 41, 43 and 45±0.5℃) for 1 h were studied. The results showed that: (1) Adult longevity of A. hygrophila species was decreased with the temperature increasing. It was 37.4 d on average at 25℃ (control). However, it dropped to 20.0 d after exposure at 45℃ for 1 h. (2) Pre-oviposition period of female A. hygrophila prolonged significantly after exposure to high temperatures over 39℃ for 1 h. It was 4.1 d on average at 25℃ (control). It prolonged to 4.8 and 7.3 d after exposure to 39 and 45℃ for 1 h, respectively. (3) Number of eggs laid by individual A. hygrophila female decreased significantly with the heat-shock temperature increasing. It was 965.1 eggs on average at 25℃, but decreased to 638.7 eggs at 39℃ and less than 260 eggs at 45℃. (4) Egg viability and offspring emergence rate of A. hygrophila was also impacted significantly by heat-shock. With the temperature increasing, the egg hatching rate dropped from 95.4% to 89.2%, and the adult emergence rate of F1 generation decreased from 87.0% to 71.3%. These results indicate that brief high temperature exposure has adverse impacts on fecundity of A. hygrophila.

Key words: Agasicles hygrophila, Alternanthera philoxeroides, high temperature exposure, fecundity, longevity, emergence rate, biological cntrol