Spodoptera litura is an omnivorous pest that damages more than 120 types of crops. It is widely distributed throughout the tropics, subtropics, and temperate zones. It is a major pest that causes damage by explosively increasing in density in a short period of time due to its excellent mobility and reproductive ability. S. litura was studied at five constant temperatures (15.0, 20.0, 25.0, 30.0, and 35.0℃), 65±5% relative humidity (RH), and 14L:10D photoperiods. The development period for eggs and larvae tended to become shorter as temperature increased. The growth period of egg, larva, and pupa by 25℃ temperature was 4.0, 32.3, and 12.6 days, respectively.

Seasonal occurrence and distribution of insect pests and their natural enemies were investigated in several Paprika greenhouses(different pest control histories). Even in the environmental-controlled greenhouses with natural enemies for controlling insect pests, there were differences in occurrence and distribution of insect pests and natural enemies by season. From March after planting, aphids and whiteflies(Myzus persicae and Bemisia tabaci) had partially occurred in all experimental greenhouses. During summer season, whiteflies and leaf mites primarily occurred and insect pest species occurred in this season were more diverse than the winter season. In the winter season, whiteflies predominantly occurred in both natural enemies and pesticide-treated Paprika greenhouses. Predatory mite, Amblyseius swirskii was difficult to maintain their populations under an average temperature below 18℃ and relative humidity below 60%.

2022년 10월부터 2023년 5월까지 친환경 딸기재배 농가에서 점박이응애는 칠레이리애응애와 사막이리응애, 진딧물은 콜레마니진디벌을 대상으로 하는 천적처리구와 유기농자재를 사용하는 관행방제구에서 천적의 해 충 밀도억제 효과를 조사하였다. 천적처리구에서 점박이응애 성충 밀도는 잎당 1.5마리 이하, 알은 4개 이하로 관리되었고, 사막이리응애는 잎당 최대 0.4마리까지 증가하여 점박이응애 밀도억제에 많은 영향을 미친것으로 보인다. 반면, 관행방제구에서 점박이응애 밀도는 천적 방사구에 비하여 오히려 많은 발생량을 보였지만, 3월 9일부터는 사막이리응애의 증가와 유기농자재의 효과로 점박이응애 밀도는 급격하게 감소하였다. 진딧물 천적 처리구에서 진딧물 밀도는 1월부터 발생하였으며 3월 상순에 잎당 0.3마리까지 증가하였으나 이후 감소하였고, 콜레마니진디벌은 진딧물 발생이 많지 않아 3.9마리/㎡(2회) 방사하는 데 그쳤다. 한편, 관행방제구 포장의 진딧 물은 유기농자재의 영향으로 거의 발생하지 않았다.

We investigated the behavioral attractive responses of a lepidopteran larva parasite, Exorista japonica to 10 synthetic herbivore-induced plant volatiles (HIPVs). These synthetic HIPVs have been revealed the attractive effect on several parasites. For each of the HIPVs, we asked the following two questions : (1) Which volatiles show the attractiveness to this parasitoid, (2) Whether the attractant directly or indirectly affects the host settlement and parasitism of the parasitoid. To experimentally address these questions, we performed 2 and 4 choice indoor cage tests. E. japonica adults were significantly attracted to benzaldehyde and (Z)-3-hexen-1-ol showing higher settlement and parasitic rates on Spodoptera litura of treatments. Compared to the untreated plots, the average parasitism of E. japonica on S. litura larvae in the benzaldehyde treatments increased by approximately 20%.

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46 mm) and males (4.20-4.62 mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring’s sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4th or 5th nymphs, the offspring’s female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.

In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3rd to 4th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.

본 연구는 성페로몬에 대한 열대거세미나방 수컷 성충의 촉각 반응 및 중복 교미 여부를 확인하기 위해 수행하였다. 성페로몬 성분인 Z9-14:Ac에 대한 열대거세미나방 수컷 성충의 촉각 반응은 농도 의존적으로 농도가 증가할수록 크게 나타났다. 조사한 7성분 중 Z9-14:Ac 성분에 대한 촉각 반응이 가장 컸다. 성페로몬의 혼합 성분에 대한 촉각 반응이 단일 성분에 비해 컸다. 열대거세미나방 수컷 성충은 실험실 조건에서 중복교 미가 가능하고, 첫 교미율이 58.3%인데 비해서 두 번째 교미율이 72.2%로 증가하였다. 교미한 수컷 성충의 촉각 반응과 교미하지 않은 수컷 성충의 촉각 반응의 차이가 없었다. 성페로몬 트랩에 교미하지 않은 수컷이 시험기간 중에 포획되지 않았다. 대조구인 교미하지 않은 암컷 성충을 장착한 트랩에서도 교미하지 않은 수컷 성충은 포획되지 않았다. 비록 실내에서 교미한 수컷 성충은 성페로몬 성분에 대해 교미하지 않은 수컷 성충처럼 촉각 반응을 보였다고 할지라도 실제 야외 망실 하우스에서 교미를 한번 한 수컷 성충은 비행 능력 등 활력의 문제로 트랩에 포획되지 않았을 가능성이 있다고 생각된다. 야외 노지에서 열대거세미나방 성페로몬에 대한 수컷 성충의 유인 정도는 추후 좀 더 많은 검토가 필요할 것으로 본다.