Biological studies of the spider mite, Tetranychus truncatus and its natural enemies.
An account is given of studies in Taiwan during 1972-73 on the biology of Tetranychus truncatus Ehara, a common pest of upland vegetable crops including beans (Phaseolus). Descriptions of the life stages are given. Continuous rearing in the laboratory resulted in a total of 31 generations in one year. The egg, nymphal and adult stages averaged 6.22, 6.25 and 10.6 days, respectively. Each female laid an average of 60 eggs in about 9 days. The natural enemies found during a field survey included Oligota oviformis (Csy.), Arthrocnodax occidentalis Felt, Amblyseius longispinosus (Evans), Stethorus hirashimai Sasaji, S. chengi Sasaji, S. loi Sasaji, Eumicromus sauteri (Esb.-Pet.), Scolothrips sexmaculatus (Perg.) , Orius sp., Anystis sp., Bdella sp. Amblyseius largoensis (Muma) and A. ovalis (Evans); the first three species appeared to afford the greatest control.