Effects of brief exposure to mild-low temperatures on the eclosion of 1st-4th level pupae of the citrus fruit fly Bactrocera minax (Enderlein)
Bactrocera minax is a major pest of citrus in China. Compared to constant relative high temperature, exposure to long, natural, low temperatures in winter contributes to the survival of B. minax pupae. However, it is still unclear how short term exposure to low temperatures (above the developmental point temperature but < 25℃) affects the survival of 1st-4th stage pupae. [Objectives] To investigate the effects of short-term exposure to different temperatures on the survival of B. minax 1st- 4th stage pupae. [Methods] Adult eclosion was investigated after pupae of different stages (1, 2-3, 4) were exposed to a range of temperatures (10, 15 and 20℃) for 2, 4 and 8 h, respectively. Pupal survival was calculated and interactions between temperature and duration of exposure were analyzed using two-way ANOVA followed by a LSD test. The significance of differences between eclosion rates following exposure to different temperatures, or exposure durations, were assessed using one-way ANOVA and a LSD test. [Results] There were no significant interactions between temperature and duration of exposure in all but 2nd and 3rd stage pupae. Eclosion rates of 1st stage pupae were 66.79% and 59.93% after exposure to 15℃and 20℃, respectively. Eclosion rates of 2nd -3rd stage pupae were 50.59% and 58.80% after exposure to 10℃ for 4 and 8 h, 54.96%, and 55.61% after exposure to 15℃ for 4 and 8 h, respectively. Eclosion rates of 4th stage pupae were 52.10%, 53.30% and 51.62%, after exposure to 10, 15 and 20℃, respectively. These eclosion rates were all significantly higher than those of control pupae kept at 25℃, (42.81%). [Conclusion] Brief exposure to mild-low temperatures improved the survival of 1st-4th stage pupae, but the degree of improvement varied with pupal stage. These results can increase pupal survival, and improve both the accuracy of forecasting adult population dynamics and the effectiveness of control measures for this pest.
NETL
NSTL
万方数据
维普
