Biology and economic threshold level of the lima bean pod borer, Etiella zinckenella (Treitschke) (Lepidoptera: Pyralidae) on soybean
1988
Bugayong, P.L.
The total developmental period of the male and female Etiella zinckenella was 27.96 and 26.84 days, respectively. The average incubation, larval and pupal periods of the male and female respectively, were as follows: 4.18 and 4.49 days; 14.44 and 14.08 days; and 10.96 and 10.20 days. The larva underwent five instars. The average longevity of the male adult was 7.02 days while the female had 8.62 days. The average preoviposition, oviposition and postoviposition periods of the female were 1.47, 6.50 and 2.10 days, respectively. The average number of eggs laid per female was 169.10 with an average daily rate of 27.22 and a percent hatchability of 43.80%. Adults of E. zinckenella were present in the field throughout the year except in May and June. There were two peaks of abundance, the first occurred in January and the second in October. Aside from soybeans, the larvae also infest Cajanus cajan, Vigna radiata, and C. mucronata. Under laboratory conditions, the duration of the different life stages, fecundity and longevity of E. zinckenella on the four host plants did not vary significantly. However, it was observed that those reared on V. sesquipedalis had the highest and those on C. cajan had the least larval mortality. Yield of soybean was greatly affected by the different population densities of E. zinckenella. The highest yield reduction was obtained on plots infested with 16 pairs of adult moths. Plots infested with 8 pairs of adults but treated with Decis 2.5 EC did not vary significantly from the control. The economic threshold level (ETL) of E. zinckenella on soybean varied during the wet and dry season. The computed ETL for the wet season and dry seson was 0.99 and 0.59 pair of adult per 2 square meters of soybean plots, respectively.
显示更多 [+] 显示较少 [-]