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.

Spodoptera litura Fabricius, 1775 (Lepidoptera: Noctuidae) is a serious crop pest with a long-distance migratory flight. To date, the DNA barcode region has been widely used in genetic diversity analysis studies of Spodoptera litura. However, the DNA barcode region showed maximum variation rate of S. litura, which from 18 regions in South Korea, was 0.608% (nine haplotypes) in previous study. In this study, four mitochondrial genes (ND4, ND4L, ND1, 16s rRNA) have higher intra-specific variation rates than the DNA barcode region. Among the four genes, The variation rate of the 16s rRNA region was confirmed to be a minimum of 0.203% (2bp) and a maximum of 1.824% (18bp). Finally, the 16s rRNA region with the highest PCR amplification efficiency and highest variation rate was selected as a high-efficiency molecular marker.

The aim of this study is to investigate the habituation phenomenon of essential oils as potential feeding deterrents in agricultural practices and their associations with taste receptors. Non-choice tests and contact-fumigation bioassays were conducted to determine the feeding deterrency and insecticidal activity of 30 commercial oils on the third instar larvae of the tobacco cutworm. The results indicated that lemongrass, fennel sweet, and clove bud oils had the highest feeding deterrency in that order, and no direct correlation between insecticidal activity and feeding deterrency was observed. To validate the habituation phenomenon, larvae were exposed to the three abovementioned oils at a 1 mg/g for 48 h, then a choice assay was conducted. It showed a significant reduction in both feeding deterrence and repellency in all cases. Similar reductions in feeding deterrence were observed when individuals exposed to the main components of the three oils: citral&limonene, anethole, and eugenol. Additionally, the oil mixture of fennel sweet and clove bud exhibited the most significant synergistic effect on feeding deterrency, suggesting a relatively slower habituation process. This reduction in feeding deterrence is presumed to be due to desensitization of the larval taste sensory organs, including the maxillary palp, lateral styloconica, and medial styloconica. Further research will be conducted to investigate the specific mechanisms and spike activity associated with these sensory organs using electrophysiological study.

본 연구는 담배거세미나방 국내 개체군의 예찰에 필요한 성유인제의 최적 조성을 찾기 위해 수행하였다. 담배거세미나방 암컷 성충에서 알 려진 두 성페로몬 성분인 (Z,E)-9,11-tetradecadienyl acetate, (Z,E)-9,12-tetradecadienyl acetate를 5.5 ~ 10.0 및 9:1 ~ 99.1, 9:1 ~ 39:1 비 율 사이에 여러 조성으로 만들어 고무격막 방출제에 담아 펀넬트랩을 이용하여 콩과 땅콩포장에서 수컷 성충에 대한 유인력을 비교한 결과, 두 성 분의 19:1 비율이 가장 적절한 유인 조성으로 결정하였다. 그러나 Z9E11-14:Ac 단독 성분 미끼에는 수컷 성충이 거의 유인되지 않았다. 이 결과 는 담배거세미나방 성충 예찰용의 성유인제 구성에는 두 성페로몬 화합물이 반드시 필요한 성분임을 나타낸다. 미끼에 담긴 성페로몬은 0.1 ~10 mg 사이에서 함량이 증가할수록 유인된 수가 많았다. 적절한 트랩 설치 높이는 1.5 m로 결정하였다.

The attraction effects of light emitting diode (LED) trap to Spodoptera exigua and Spodoptera litura adults were evaluated in greenhouse and compared with those of no light trap, which is typical used in commercial trap. At this time, in order to attract these two species of moths, sex pheromone traps were installed at the top side according to the degree of tomato growth inside the tomato cultivation greenhouse around the LED trap. In addition, two types of light-emitting traps (420 nm, 470 nm) were installed in the greenhouse at 1/40 m2, respectively. Also two sex pheromone were installed inside of the greenhouse according to the height of the tomato plants. 10 days later, Blue-light trap(BLB, 470 nm wavelength) was 3.1－3.5 times more attractive than Violet-light trap(VLB, 420 nm wavelength) in S. exigua (105.6 ± 7.3) and S. litura (42.0 ± 3.1) respectively, whereas the no-light trap was little attractive to S. exigua (33.7 ± 2.8) and S. litura (12.0 ± 1.5). On the other hand, after the installation of the sex pheromone trap and the LED trap, there was no damage to S. litura (Fabricius) and S. exigua in the pesticide-free area, indicating a high possibility of control. At this time, the operating cost of the two types of LED traps was 80 won/m2 per unit area, and it was confirmed that both types of moths could be controlled. In addition, as a result of confirming the number of two types of moths caught in the sexual pheromone trap and two types of LED traps after 4 months, it was judged that eco-friendly control was possible as more than 373 moths/trap were attracted to the two types of moths.

Spodoptera litura Fabricius is the serious, polyphagous pest of various crops. Due to the high resistant to most of chemical pesticides, it is hard to control S. litura in the fields. We investigated the virulence of four entomopathogenic nematodes (EPNs) in each larval stage. All EPNs were more effective to younger larvae than older larvae. Mortality, larval penetration rate and reproduction rate were significantly higher in H. indica, S. carpocapsae and S. longicaudum than the H. bacteriophora. Three high effective EPNs induced complete mortality of first instar larvae within 48 h, but of fifth instar larvae within 72 h. These EPNs also highly effective to control S. litura in pot assay. Thus, H. indica, S. carpocapsae and S. longicaudum, can be used as efficient biological control agents of S. litura.

Various plant extracts were widely used to control plant diseases and insect pests in organic farming system. This study was conducted to evaluate insecticidal activity of plant extracts against three moth in vitro. Insecticidal activity of 21 kinds of farm-made plant extracts including snowbell tree, sweet oleander leaf, sweet oleander and white cedar, collected from farmhouses were tested against diamondback moth (Plutella xypostella) and tobacco cutworm (Spodoptera litura) larvae. In addition, four plant extracts (pyrethrum flower, derris, neem and Sophora flavescens) were tested for insecticidal activity against Potato tuber moth (Phthouimaea operculella) larvae. As a result of insecticidal test on diamondback moth, insecticidal activity of pyrethrum flower extract was found to be 50% or more in diluted 100 times. The insecticidal activities against tobacco cutworm were 92.5% at snowbell tree extract, 77.5% at the sweet oleander leaf and white cedar extracts. Among the plant extracts, insecticidal activity of 300 times-diluted pyrethrum flower and derris extract was 85%, neem and Sophora flavescens extracts were similar to non-treatment. Consequently, pyrethrum flower extract and snowbell tree, sweet oleander leaf, white cedar extracts and pyrethrum flower, derris extracts for controlling diamondback moth and tobacco cutworm and potato tuber moth were selected. We think the selected organic materials can be used to control diamondback moth and tobacco cutworm, potato tuber moth under organic farmhouse condition.

친환경 해충 방제 방법 중 LED를 비롯한 빛을 이용한 해충방제가 활발하게 연구되고 있으며, 해양, 농장, 축사 등 산업적인 측면뿐만 아니라 사회 전반적인 분야에서 활용되고 있다. 해충 기피램프의 광원은 주로 LED(550~630mm)가 활용되고 있으나 출력이 약해 넓은 면적에 적용이 힘든 단점이 있다. 이에 제논램프를 이용한 넓은 면적에 적용 가능한 식물재배용 해충 기피램프를 적용하여 담배거세미나방에 의한 작물 및 피해과실률을 비교하였다. 특정 파장(870~920mm, 자외선:가시광선:적외선=2:34:64)을 방출하는 제논램프를 높이 2.5m, 2/10a개 설치하였다. 광원의 처리는 3수준(일몰 후 2시간 경과 시점부터 2시간, 4시간, 무처리)으로 하였으며, 나방의 유입을 원활하게 하기 위하여 모든 출입구를 개방하였다. 과실 피해가 발생한 후 출입구를 폐쇄하여 제논램프가 유입된 나방의 작물 및 과실 가해를 억제하는지 조사하였다. 토마토 재배는 경상남도 함안(35° 15’ 0”N / 128° 25’ 0”E)의 유리온실(6*10*5m)에 토마토(데프니스, 유럽종)를 재식간격 1m(줄 간격), 0.5m(포기사이거리)재배하였다. 생육기간은 4월 12일 정식하여 8월 2일까지이다. 토마토 재배기간 동안 격주간격으로 생육(초장, 엽면적, 잎, 과실, 줄기의 생체중 및 건물중)조사를 하였으며, 매주 피해과, 정상과의 수량을 조사하였다. 조사 결과 대조구에서 엽의 건조 중량이 21%정도 낮았으며, 줄기의 건조 중량은 2.5배 높았으며, 초장, 엽면적은 차이가 없었다. 제논램프 처리 시간에 따라 피해과실률((피해과실 중량(g)/총 과실 중량(g))*100)은 제논램프 4시간 : 초기 7.59 → 2주 후 0.02a, 2시간 : 초기 3.41 → 2주 후 6.32b, 대조구 초기 10.00 → 2주 후 42.71c% (Analysis of variance, p < 0.1) 로 조사되었다. 대조구에서는 유입된 담배거세미나방이 온실 내에서 번식함에 따라 엽의 생체중은 감소하였으나 엽면적에서는 유의한 차이를 보이지 않았는데, 이는 대조구의 잎이 심하게 황화된 경우가 많았고, 이 때문에 엽면적은 증가하였으나 중량감소 하였다. 제논램프 2시간, 4시간 처리에서는 담배거세 미나방에 의한 작물 및 피해과실률이 감소하였으며, 제논램프 4시간 처리에서 유의하게 높은 방제 효과를 보였다.

1분 간격 자동 잎면적 분석을 통해 온도에 따른 담배거세미나방 유충의 섭식과 발육을 조사하였다. 20, 25, 30℃의 세 온도에서 피망 잎을 배지에 부착하여 담배거세미나방 유충에 제공하였고 하루에 한번내지 두번 새로운 잎을 갈아주었다. 30℃에서 담배거세미나방 유충은 탈피 직후 섭식을 즉시 시작하여 1회 섭식은 10~15분 지속하고, 60~90분 간격으로 섭식을 하였다. 이러한 섭식 행동은 약 30~50시간 지속되며 탈피 직전 10~16시간 동안은 섭식이 중단되었다. 탈피 후 앞서의 섭식 패턴은 다음 영기에서 동일하게 반복되었다. 25℃에서 담배거세미나방 유충의 영기 내 섭식 기간은 약 32~53시간 지속되며 탈피 전 비섭식 기간은 16~22시간 지속되었다. 20℃에서는 영기 내섭식 기간은 60~133시간으로 크게 증가하고 비섭식 기간도 11~38시간으로 다른 온도에 비해 길어졌으며 다른 온도와 달리 7령충까지 발육하였다. 2령충에서 고치 형성 전까지의 발육 시간은 20℃에서는 39046분(27.1일)이 소요되었고 25℃에서는 17626분(12.2일), 30℃에서는 14168분(9.8일)으로 조사되었다. 각 온도별 유충의 섭식량은 영기에 따라 지수적으로 증가하였다.

The tobacco cutworm, Spodoptera litura(Fabricius) is serious pest that hurts tomato crops, actives long time of the year. Without pesticide applications, sex pheromone delta traps through experiment first and second half setting during cultural seasons in glasshouse and greenhouse. We investigated captured number of S. litura both in and out side of the two type of tomato cultivated greenhouse. As a result of investigation, captured number of S. litura showed the wave and three high peak typed graph throughout 10 months experiment. First time expression of S. litura was late April in outside installed traps and after that occurrence rate increased gradually until late August. In september, the rate decreased remarkably to middle November in both in and out side treated traps. The result also expressed that captured average number of S. litura in inside of the greenhouse were 8~10 units, and were 15~20units in outside treated traps. Simultaneous installation of internal and external sex pheromone traps succeeded in eliminating a considerable number of S. litura male moths, and the number of larvae was expected to be considerably reduced. Consequently in the experiment, captured male number of S. litura were about 220 units in outside, on the other about 80 of S. litura captured in inside installed traps.

약제 처리에 따른 담배거세미나방(Spodoptera litura) 유충의 섭식 행동 및 반응을 조사하기 위해 1분 간격으로 잎면적을 자동 측정하였다. 담배거세미나방 유충의 섭식 행동은 섭식기와 비섭식기가 뚜렷하게 구분되었으며, 섭식기가 끝나면 비섭식기를 거쳐 탈피를 하고 다시 섭식기에 들어갔다. 1회 섭식 지속 시간은 약 15분으로 조사되었고, 영기 내 평균 섭식 회수는 약 27.5회로 섭식 지속 시간과 마찬가지로 영기에 따른 차이는 없었다. 약제 처리는 피망 잎을 Buprofezin methoxyfenozyd과 BT (Bacillus thuringiensis) 500ppm 약액에 10초간 침지 처리하였다. Buprofezin methoxyfenozyd를 처리 하였을 경우 섭식 시간은 평균 8~9분으로 감소하였고, 치사 전까지 섭식량은 각각 176mg으로 조사되었다. 하지만 BT제를 처리 시에는 담배거세미나방 유충은 치사하지 않았다.