벗초파리기생벌인 A. japonica의 벗초파리 유충의 발육단계에 따른 기생특성과 기생당한 유충과 번데기에서 형태적인 차이를 조사하였다. 또한 A. japonica의 우화기간이 벗초파리 우화일수 보다 더 소요되는 것을 확인하였다. A. japonica는 벗초파리 유충에 효과적인 기생 및 살충 효과를 나타내었으며 벗초파리 방제를 위한 천적으로 활용이 가능할 것으로 보인다.

This study was carried out to confirm the predatory and developmental features of N. stenoferus. We determine the host range of N. stenoferus. As a result, it was confirmed that Aphis gssypii, Myzus persicae, Planococcus citri, and Frankliniella occidentalis. N. stenoferus is thought to be able to feed on other micro pests. The test for a developmental period of N. stenoferus at 25℃ showed that the egg period was about 10 days. The nymphal period was about 18 days. Each nymphal period from 1st instar to 3rd instar nymphs was about 3 days. And the nymphal period of 4th and 5th were about 3.5 and 6 days, respectively. The female adult laid eggs in stem tissue or on leaves, and sometimes on the soaked cotton for water supply.

It is uncommon to fumigate the live plants in quarantine. Ethyl formate (EF) fumigation was carried out in a 0.275 m3 chamber in laboratory for 12 h (over-night) to evaluate the mortality of 4 insect pests and to evaluate the phyto-toxic effect on their host plants. The tested doses were 1, 1.5 and 2 mg/L EF with or without nitrogen gas (N2). The phytotoxicity was evaluated 7 days post-fumigation based on the damage index (DI) scaling 0-4. Mortality >80% were recorded against thrips, whitefly and aphid in all the EF or EF + N2 treatments. Two-spotted spider mite was highly tolerant (<20% mortality at the highest dose tested) to EF. Except for perilla and sesame (DI = 4), EF was non-toxic to other vegetable crops at 1.5 mg/L EF. However, 1.5 mg/L EF+N2 increased DI by 3 for tomato, watermelon and green pumpkin. This new method fumigating live plants certainly demands lots of further experiments to ensure its practical application in farm level. (Supported by PJ0133562018, RDA)

Ethyl formate (EF) fumigation under green house condition is a new concept. Its concentrations inside and surrounding of the glass house (GH) and vinyl house (VH) were evaluated for 4 h (during daytime) and 12 h (during nighttime) after fumigation along with the evaluation of post-fumigation EF concentrations. The cumulative EF concentration × time (Ct) value of the 6 sampling positions in VH were 22.67 and 17.53 g·h/m3, respectively for day and night fumigation, which were 2.62 and 4.53 g·h/m3 respectively for day and night application in GH. The EF level (PPM) outside the VH and GH as well as after 20-min post fumigation were < 50 ppm revealing its safety level as its’ threshold limit value (TLV) is 100 ppm. The new technology using liquid EF fomulation could be a key option in smart-farm technologies in future. (Supported by PJ0133562018, RDA)

This study was carried out to confirm the parasitic and developmental features of A. japonica and D. suzkii was used as a parasitic natural enemy. A. japonica attacked the D. suzukii larvae and the emergence of adults were observed from D. suzukii pupae. Black spots were observed in parasitized D. suzukii larvae. Mortality of parasitized larvae, rate of parasitic and developmental feature were investigated according to developmental stages of host, D. suzukii. Mortality and rate of parasitic of D. suzukii larvae were the highest when second instar larvae were attacked. Developmental period of parasitized D. suzukii larvae showed differences to developmental stages, but there was no significant difference in developmental stage of pupal period.

Methyl bromide (MeBr) is well-known as a hazardous chemical to exposed fumigators and related workers as well as a ozone depletion chemical. According to recent report in USA and Korea, when MeBr fumigated on orange and grape at low temperature (<10℃), absorbed MeBr on fruits was slowly released to workplace. To replace MeBr practices urgently, ethyl formate (EF) fumigation is considered safer to worker (TLV of EF = 100 ppm compared to MeBr's = 1 ppm) and free from residual problem. We reports confirmative liquid EF (FumateTM) with N2 trials, which is cost-effective and non-CO2 gas emitted, on imported grapes. The 4hr-fumigation of 70 gm-3of EF (CTP > 114 gh-3) in scale-up chamber (10m3) fumigation (20% l.r.), showed efficacies to many kinds of insect pests, non-phytotoxic damage, providing safer guideline at workplace.

The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests world wide. In this study, we determined electron beam doses for inhibition of normal development of the L. trifolii and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs, larvae, pupae and adults were irradiated with increasing doses of electron beam irradiation (six levels ranges from 30 to 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and pupae was lower than those of untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein with in 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for sterilization of L. trifolii.