Development under Constant Temperatures and Seasonal Prevalence in Soybean Field of the Bean Pyralid, Omiodes indicatus (Lepidoptera: Crambidae)
The bean pyralid, Omiodes indicatus (Fabricius), moulted 4 times during larval period. When temperature increased from 15 to 20, 25, and 30℃, the developmental period of immature stages was shortened, 18.2, 7.5, 5.0, and 4.1 days of egg period, 51.8, 20.0, 12.7, and 9.9 days of larval period, 29.5, 12.0, 8.0, and 5.9 days of pupal period, respectively. Adult longevity was 16.0, 14.7, 11.2, and 7.5 days at respective temperatures. A female adult layed 57.0, 63.3, 82.2, and 31.7 eggs in 3.7, 6.0, 5.8, and 3.0 days of oviposition period at the same temperature regimes, respectively. Field survey in 2006 and 2007 showed that leaf damage on paddy field and upland soybeans began to appear in mid July, reaching its peaks in mid August and late September. Adults of the bean pyralid appeared in mid July and peaked in late August and early October.