The Sizes of Sitophilus zeamais in Different Life Stage

Abstract

Abstract Knowing the developmental states of stored grain insects, especially for the immature stages hidden in cereal kernel, such as Sitophilus zeamais, could be in favor of monitoring early and controlling effectively. Atlas and scale parameters on different developmental stages of S. zeamais in wheat kernel were captured and described by three-dimensional microscope of super depth of field observation. The four instars of larva, pre-pupa, pupa, new adult, old adult in kernel could be seen by dissecting the infested kernels. The length, height, and width of larva body increased with insect development and centralized the sizes corresponding to the four instars of larva. The length of larva body centralized near 554, 746, 1 462, and 2 147 μm. The height of larva body centralized about 388, 575, 847, and 1 651 μm. The width of larva body centralized near 340, 598, 798, and 1 568 μm. Head capsule width was in same size for each exuviating period, centralized near 203, 317, 535, and 603 μm, and got big sharply with the instar changed. Developmental duration of four larva instars was about 21 days reared in wheat, less than 28 days reared in maize as published. The atlas and description should be helpful for monitoring the S. zeamais development hidden in cereal kernels and designing control strategy. Supported by National Keypoint Research and Invention Program of the Thirteenth (2017YFC1600804).