Tolerance of Megabruchidius dorsalis (Coleoptera: Chrysomelidae) at different developmental stages to short-term high temperature stress and its physiological response.

Abstract

The seed beetle, Megabruchidius dorsalis (Fåhraeus), is an oligophagous pest that damages Gleditsia seeds, thereby severely reducing their yield and quality. To explore the tolerance of M. dorsalis to short-term high temperature stress, the effect of short-term exposure to high temperatures (28, 30, 35, 40, 45, 50, 55, and 60 °C treated for 1, 2, and 3 h) on different developmental stages of M. dorsalis and its physiological response of adults were conducted. The results showed that the egg hatching rate and adult emergence ratio of M. dorsalis were significantly decreased after short-term high temperature stress. Short-term high temperature stress significantly prolonged the longevity and preoviposition period of M. dorsalis adults, but decreased their fecundity. The eggs, larvae, and adults of M. dorsalis were completely controlled at 55, 60, and 50 °C, respectively. High temperature significantly decreased the water content, but increased malondialdehyde content in female and male adults with the increase in temperature. The glycogen and glycerol content of female adults first significantly decreased and then increased as the temperature rose, while that of male adults significantly increased. These findings could provide a reference for formulating high temperature treatment strategies for M. dorsalis.