The survival rate and number of parasitized host of Encarsia formosa Gahan and Eretmocerus eremicus Rose were observed at low temperature conditions (6, 8, 10 and 12 ± 1oC, RH 70 ± 10%, in dark condition. Mummy of Encarsia formosa was stored at 12oC, for 70% of the mummies survived for 10 days. After 6-days storage at 12oC, number of parasitized host of the parasitoids was decreased to 35.9 (67.6%, compared to control). Mummy of Eretmocerus eremicus was stored at 12oC, and 70% of the mummies survived for 14 days. After 6-days storage at 12oC, number of parasitized host was decreased to 31.6 (83.6%, compared to control). Our results suggest that 12oC was most suitable temperature for storage of Encarsia formosa and Eretmocerus eremicus.
Effectiveness of Encarsia formosa (Hymenoptera: Aphelinidae) to control Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) was investigated in the commercial tomato greenhouse from January to June, 2010. Densities of T. vaporariorum were monitored using the yellow sticky trap for adult, and a lupe (x10) for 4th instar nymph and pupa at 1 week interval. Tomato seedlings were transplanted in mid-January and the nymph and adult of T. vaporariorum were first discovered in February 4th. E. formosa was applied as a mummy card at a recommended density (3 parasitoids per 1m2) at 2 weeks interval for 8 times. Mummy cards were collected 2 weeks later and the emergence and survival ratio of E. formosa were examined. Density of adult T. vaporariorum was significantly lower in the treatment plot (F=42.48, p=0.0001). The control efficiency ranged from 57.3% to 88.5%. The nymphal density was also significantly lower in the treatment plot (F=8.85, p=0.0053). The control efficiency was 84% on 25th March, 75% on 18th May and 95% on 25th May. Maximum 50% parasitism by E. formosa occurred in the treatment plot. The emergence and survival rates of E. formosa on mummy cardboards that were released in the greenhouse during February to March were only 53% and 41%, respectively. These rates increased to >70% as the temperature rises.
온실가루이의 발생량은 성충과 약충 모두 토마토보다 오이에서 많았다. 끈끈이 트랩에 온실가루이는 오이에 접종후 3일째부터 유인되기 시작하여 3회의 발생최성기를 보였으며 온실가루이좀벌은 접종 15일째부터 성충이 유인되었다. 온실가루이 성충은 오이잎의 최상위 부분에 주로 서식하고 있었으며 약충은 초기에는 상위부분에서, 40일째 이후에는 하위부분에서 주로 발생하였다. 온실가루이좀벌 성충은 중상위 부분에서 많이 발생하였으나 부위별 차이는 거의 없었으며, 온실가루이좀벌에 의한 온실가루이 mummy는 오이의 중하위부분에서 발생이 많았다. 온실가루이의 방제를 위하여 온실가루이좀벌을 방사하는 시기는 황색끈끈이 트랩에 온실가루이 성충이 1주일 동안 5마리 정도 잡히기 시작할 때 온실가루 이좀벌mummy를 오이 5주당 50마리(1tag)씩 방사한 경우 방사후 40일정도에 방제효과가 인정되었다.