Low Temperature Storage of Eggs Improve the Development and Reproduction of Locusta migratoria (Orthoptera: Acrididae).

Locusta migratoria L. is an insect with significant economic value. Improving the long-term storage of L. migratoria eggs will help promote the large-scale rearing of this insect. We assessed multiple fitness parameters and enzyme activities of locusts emerged from eggs exposed to 4 °C for 1-4 wk. Locusts emerged from eggs stored at 4 °C for 2 wk showed significantly improved development and reproduction compared with locusts emerged from eggs stored for other time periods. The preimaginal survival rate increased significantly after 2-wk storage while it decreased significantly after 4-wk storage compared with other storage times. The fecundity, hatching rate, and growth rate increased significantly after 2-wk storage, but decreased significantly after 1, 3, and 4 wk compared with the control. However, the preimaginal developmental duration decreased significantly after 2-wk storage but increased significantly after storage for 1, 3, and 4 wk compared with the control. The activities of esterase, glutathione-S-transferases, phenol oxidase, and chitinase were obviously fluctuated with changes in intrinsic rate of increase (rm). These results showed that eggs stored at 4 °C for 2 wk could improve the development and reproduction of locust emerged from eggs, and four enzymes activities in above could reflect the health of locust. Our results could be useful in developing large-scale rearing protocols for L. migratoria.