Seasonality of insect pests of soybean and mungbean in Taiwan.
The seasonal distribution of several insect pests of soyabean and mung bean (Vigna radiata) in Taiwan was determined by monitoring their incidence on crops of the 2 legumes sown once every 2 weeks from April 1975 to December 1980. The data showed that Melanagromyza sojae (Zhnt.), Ophiomyia centrosematis (de Meij.), Nezara viridula (L.), Anomala cupripes (Hope), A. expansa Bates, Etiella zinckenella (Treitschke) and Aphis glycines Mats. were the major pests of soyabean, while the first 2 species and O. phaseoli (Tryon) were the main pests of mung bean. M. sojae, O. centrosematis and O. phaseoli occurred throughout the year but caused severe damage only during autumn. The main activity periods were May-October for N. viridula, mid-April-October for Anomala spp., September-May for E. zinckenella and October-March (the coolest time of year) for Aphis glycines.