Studies on the biology and control of Peridroma saucia Hubner.
The biology of the noctuid Peridroma saucia was studied in Zhaojue and Liangshan Yi Autonomous Prefecture, China, in 1977-81. The larvae infested maize, sorghum, wheat, potato, soyabean, Brassica spp. and Melilotus indica. At Zhaojue, the pest produced 2-3 generations a year at an altitude of 2150 m, the fully-grown larvae overwintering in the soil at a depth of 5-10 cm. Adults emerged between 19.00 and 23.00 h. The ratio of females to males was 1.53:1. Copulation occurred within 4 days of emergence. Females laid an average of 200-500 eggs (a maximum of 1000) on the surface of the ground or on the leaves of weeds. Larvae consumed an average of 3873 m2 leaves of maize in a lifetime, with approximately 80% consumed in the 6th instar. Effective control (90%) of this pest was achieved with 80% DDVP [dichlorvos] (1:1000), 90% trichlorfon (1:100) or 25% DDT emulsion.