Development, reproduction and life table parameters of Tetranychus phaselus Ehara (Acari: Tetranychidae) on two bean host plants

Investigations into the life history characteristics of pests on host plants can provide important information on pest forecast and management. Tetranychus phaselus Ehara is a polyphagous pest distributed in China, Russia, Japan and Korea. Glycine max and Phaseolus vulgaris are two most economically important host crops of T. phaselus, and the increasing planting area of the two plants may facilitate the occurrence of the pest. Here we investigated the development, survival, reproduction and life table parameters of T. phaselus on G. max and P. vulgaris and how these traits vary between the two plants. We showed that the developmental period from egg to adult was significantly shorter on G. max than on P. vulgaris for both males and females. Tetranychus phaselus had significantly higher egg hatchability and egg-to-adult survival on G. max. Tetranychus phaselus had different lifetime reproductive pattern on the two host plants and produced significantly more daily and lifetime number of eggs on G. max than on P. vulgaris. We showed that females fed on G. max had significantly higher intrinsic rate of increase (r<sub>m</sub>) and net reproductive rate (Ro) and shorter generation time (T) and doubling time (Dt). These results suggest that G. max (soybean) is a more favorable host plant for T. phaselus, and the increasing planting area of these beans particularly soybeans may facilitate the occurrence of T. phaselus.