Research Articles : Development of the Turnip Aphid, Lipaphis erysimi Kaltenbach (Homoptera: Aphididae), and Test of Insecticidal Efficacy of Some Commercial Natural Products = Research Articles : Development of the Turnip Aphid, Lipaphis erysimi Kaltenbach (Homoptera: Aphididae), and Test of Insecticidal Efficacy of Some Commercial Natural Products

다국어 초록 (Multilingual Abstract)

The turnip aphid is a worldwide pest, damaging mainly to crucifers. In order to understand the life parameters of Lipaphis erysimi for the eventual goal of control, the developmental periods, survival rates, lifespan, and fecundity of the species were investigated under five temperature regimes (15℃-35℃). Furthermore, the efficacy of several environment-friendly agricultural materials (EFAMs) that are on the market was subjected to test in order to obtain further accurate information. The developmental period of the turnip aphid nymph was longest at 15℃ as 16.9 days, shortened as temperature goes up to 25℃ (5.4 days), and then somewhat increased at 30℃ (5.9 days), suggesting that the most efficient temperature for nymphal development could be around 25℃. Mortality of the nymphal turnip aphid was obvious at 35℃, whereas it was minimal at other temperature schemes. The longevity of adults shortened as temperature goes up to 30℃. In particular, the maximum lifespan for adults continued for 55 days at 15℃, but shortened to 21 days at 30℃. The total fecundity was 35.7 at 15℃, 81 at 20℃, 64.2 at 25℃, and 6.6 individuals at 30℃, showing the highest fecundity at 20℃. After the turnip aphids were successfully stabilized in indoor environment the insecticidal activity was tested and mortality was determined 12, 24, 36, and 48 hrs after EFAMs are treated. Several on-the-market EFAMs showed more than 90% of insecticidal activity within 24 hrs or 48 hrs, but a few showed less than 90% activity, signifying importance of selection of proper EFAMs.