Immune priming is an increased immunity after prior exposure to a specific pathogen as a kind of adaptive immunity and occurs in insects. However, its underlying mechanism is elusive in insects. Immune priming was detected in a lepidopteran insect, Spodoptera exigua. Prior infection with a heat-killed pathogenic bacterium, Xenorhabdus hominickii, increased survival upon the second infection of the live bacteria compared to larvae without pre-exposure. Plasma collected from larvae with the prior infection significantly up-regulated cellular and humoral immune responses compared to the similar treatment without prior exposure. However, when the active plasma exhibiting immune priming was heat-treated, it lost the priming activity, suggesting a presence of protein factor(s) in the immune priming. Lipocalin is a lipid carrier protein and is well known in vertebrates for diverse physiological functions including immunity. An apolipoprotein D3 (ApoD3) is known to be a lipocalin functioning in immune priming in a mosquito, Anopheles gambiae. A homologous ApoD3 (Se-ApoD3) was identified in S. exigua. Se-ApoD3 was expressed in all developmental stages and larvae, it was highly expressed in hemocytes. RNA interference (RNAi) of Se-ApoD3 expression was performed by injecting its specific dsRNA. The larvae treated with the RNAi were impaired in cellular and humoral immune responses. Furthermore, the plasma collected from RNAi-treated larvae lost the immune priming even at the prior exposure. These suggest that Se-ApoD3 mediates the immune priming in S. exigua.

Resistance development in insect pests against pesticides is one of the most important issues for pest management. Biological control is an attractive strategy for suppressing insects that have become resistant to chemical pesticides. The smaller tea tortrix Adoxophyes honmai (Lepidoptera: Tortricidae) is a serious pest of tea and has acquired resistance to various chemical pesticides, and baculovirus agents have been developed to control this pest in Japan. However, there was great concern about whether A. honmai might also acquire resistance against baculoviruses. To address this question, we developed a model resistant population and studied the mechanism of resistance in A. honmai against baculoviruses. A population of A. honmai that is resistant to nucleopolyhedrovirus (NPV) was selected by exposing a field-collected A. honmai population to the 70% lethal concentration (LC70) of NPV over multiple generations in the laboratory. After 155 generations, the selected strain (Resistant strain; R-strain) showed over 400,000-fold higher resistance to AdhoNPV than the non-selected strain (Susceptible strain; S-strain). In this presentation, mode of resistance of R-strain against baculoviruses were discussed.

경남 창원과 진주의 농약 무살포 및 유기농 단감원에서 단감 잎을 가해하는 해충을 조사한 결과 국내에서 단감 해충으로 기록되지 않은 3종 을 채집 동정하였다. 동정된 종은 가을뒷노랑밤나방, 푸른빛집명나방, 감잎가는나방(신칭)이었다. 이들의 채집기록, 형태, 기주와 간단한 생태를 조사하여 보고한다.

Until now, seven species, Acosmeryx nega, Herpetogramma luctuosalis, Ostrinia furnacalis, Endoclyta excrescens, Spodoptera litura, Paranthrene regalis, and Nippoptilia vitis, have been known as lepidopteran grape pests in Korea (Woo, 1980; Lee, 1981; Kim, 1991; NIAST, 2002; Korea grape community, 2009). We discovered thirteen additional species belonging to eight families from Gwangwon and Chungbuk provinces, Korea. Additionally, we corrected the previous records of Deuterocopus albipunctatus and Nppoptilia vitis. They were identified by adult external or genitalic characters first, and also confirmed by the COI marker, compared with two public databases, NCBI and BOLD.

Three lepidopteran insect pests of the legume pod borer, Maruca vitrata (Lepidoptera: Pyralidae), the soybean pod worm, Matsumuraeses phaseoli (Lepidoptera: Tortricidae) and an Ostrinia spp. (Lepidoptera: Pyralidae) attacking adzuki bean, Vigna angularis, were confirmed as the major insect pests during the reproductive developmental stage of adzuki bean, and M. vitrata existed dominantly. Almost all plants in the adzuki bean field were in jured by at least one of the three species, and 15~60% of reproductive organs were injured. Unbloomed inflorescence occurred continuously through the reproductive stage of adzuki bean. While the flower was many at the early stage and its number soon decreased, the pod was few at the early stage, but its number increased soon and maintained at a constant level. The results suggested that the adzuki bean injured by insect pests compensate the flower loss by developing new inflorescence, but the compensation do not cause the development of new pods. While M. vitrata and M. phaseoli were observed in flowers, pods and stem mainly during the first half of reproductive stage of adzuki bean, Ostrinia spp. was observed only in pods and stem during the second half. In addition, while all instars of larvae of M. vitrata were observed, larvae between the third and fifth instars for M. pahseoli and Ostrinia spp. were observed.

Development of pellet-type artificial diet for insect was tried by using a twin screw extruder(TSE). Screws were arranged several times and two reverse screws were equipped on the foreparts of 2 axes of TSE. Pellet-type diet could be produced successfully under conditions of TSE set as the following. , 300 rpm of main motor speed, 228 rpm of feed motor speed, 75㎖/min of running water speed and 5 ㎜ of extrusion diameter. The optimum adding quantity of water to the manufactured diet was 1.2~1.5 times of dry diet. On the rearing results of beet armyworm, Spodoptera exigua and common cutworm, Spodoptera litura with the pellet-type diet, the final survival ratio (emergence rate) of these two species was over than 50%, and so it was concluded that the manufactured pellet-type artificial diet was sufficient dietetically to rear those insects.

유기농 답전윤환밭 및 연속밭의 옥수수 8품종(얼룩찰1호, 흑점2호, 일미찰, 흑진주찰, 찰옥4호, 미백2호, 대학찰)과 수수 7품종(황금찰, 앉은뱅이수수, 목탁수수, 소담찰, DS202, 남풍찰, 동안메)에서 나방류 발생 및 수량 특성을 조사하였다. 조명나방 성충은 년 3회 최성기를 보였고 담배나방류 성충들은 3-4회 최성기를 보였다. 또한 조명나방 유충에 의한 옥수수 및 수수의 잎과 줄기 피해율은 시간이 지날수록 증가하는 경향을 보였는데, 수수의 조명나방 유충에 의한 피해율은 8월 중순에 급격히 증가하였다. 미흑찰, 얼룩찰1호, 일미찰, 흑점2호, 미백2호 등 옥수수 품종들에 대한 조명나방 유충에 의한 피해율은 윤환밭과 연속 밭 간 통계적으로 유의한 차이(P=0.05)를 보였고, DS202 품종(83%와 89%)을 제외한 나머지 6종 수수 품종들의 조명나방 유충에 의한 피해율은 연속밭에서 높거나 비슷하였다(50-92%). 옥수수의 나방 유충에 의한 이삭 피해율은 5%(찰옥4호)에서 38%(흑진주찰)였는데, 대학찰 품종은 답전윤환밭(33%)에서 연속밭(14%)에 비해 상대적으로 더 높은 피해를 입었다. 답전윤환 수수 포장에서 소담찰(94%)과 DS202(82%)가 높은 피해율을 보였고, 연속밭에서는 7개 수수 품종 모두 78% 이상의 피해율을 보였다. 흥미롭게도 답전윤환밭 및 연속밭의 옥수수와 수수 품종들에 대한 조명나방 유충에 의한 평균 피해율과 평균 침입공수 간에는 각 정의 상관관계(옥수수 r=0.69윤환밭, 0.95연속밭; 수수 r=0.93윤환밭, 0.97연속밭)를 보였다. 또한 수확 후, 유기농 윤환밭 및 연속밭 포장에서 나방 유충에 의한 옥수수 8품종들과 수수 7품종들의 평균 피해율과 이삭무게 또는 천립중(g) 간에 부의 상관관계(옥수수 r=-0.38윤환밭, -0.49연속밭; 수수 r=-0.70윤환밭, -0.57연속밭)를 나타냈다. 이상의 결과는 유기농 옥수수 및 수수 재배포장에서 나방류의 관리가 수량 확보에 매우 중요하다는 사실을 의미한다.