A mass rearing method for phytoseiulus persimilis acarina phytoseiidae i. leaf morphology and growth of soybean and kidney bean development and oviposition of tetranychus urticae acarina tetranychidae on the beans and fecundity of phytoseiulus persimilis and three tetranychus species
Ashihara, W.; Inoue, K.; Osakabe, M.
Bulletin of the Fruit Tree Research Station Series E (Akitsu) (6): 91-102
To develop an efficient mass rearing technique for Phytoseiulus persimilis, the following comparative studies were conducted: (1) growth of 13 varieties of soybean and 11 varieties of kidney bean; (2) development and reproduction of Tetranychus urticae on several varieties of both types of bean; (3) development and population growth of T. urticae, T. cinnabarinus, T. kanzawai on kidney bean; and (4) oviposition of P. persimilis on the Tetranychus species. Generally, kidney bean had a higher growth rate and larger leaf area than soybean. Among the 11 varieties of kidney bean, 'Honkintoki' and 'Kintoki' which resemble 'Purple Pod', had the largest leaves. While there was little difference in the developmental periods of T. urticae among the bean varieties (Table 2), the ovipositional rates of the spider mite on kidney bean was higher than on soybean (Table 3). When the number of eggs laid by the adult females was compared among the kidney bean varieties 'Nagauzura' (which resembles var. 'Dwarf Horticultural'), 'Top Crop', 'Honkintoki' and 'Kintoki', the latter two displayed more deposited eggs. 'Top Crop' leaves had hook-shaped pubescences in which the legs or palpus of the spider mite occasionally became entangled. Thus, kidney bean, especially vars. 'Honkintoki' and 'Kintoki' are suitable host plants for prey spider mites. No difference was apparent in the development period of the three Tetranychus species on kidney bean (Table 4), but the oviposition rate of T. kanzawai was the lowest among the three. Population increase of the three Tetranychus species on potted kidney bean plants was compared. The population of T. kanzawai decreased faster than other species when the host plant grew poorly or there was progressive leaf damage caused by the mite. The oviposition rate of P. persimilis was not significantly different when the three Tetranychus mites were provided as prey. T. kanzawai is thus less suitable as prey for P. persimilis because of its lower reproductive potential as compared with the other two Tetranychus species.