억새는 바이오에탄올 작물로써 현재 경남 산청, 전남 화순, 전북 익산 지역에서 대규모로 재배되고 있다. 억새 재배지에서 가장 많이 피해를 주는 해충으로는 이화 명나방으로 억새 줄기에 구멍을 뚫고 들어가며 결국 도복되어 생산량을 감소시킨 다. 억새 재배지가 화학적방제가 어려운 상수도 보호구역과 하천 주변에 식재되어 있어 곤충병원성 선충과 곰팡이 등을 이용하여 환경친화적 방제를 실시하였다. 이화명나방 유충에 대한 환경친화적 방제 인자로써 Steinernematidae과의 4종 (Steinernema carpocapsae Pocheon strain, S. carpocapsae Iksan strain, S. monticolum Hwasun strain)과 Heterorhabditldae과의 1종(H. bacteriophora Hamyang strain), Beauveria bassiana, Bacillus thuringiensis var. kurstaki를 이용하였다. 이화명나방 유충에 대한 실내실험 결과, S. carpocapsae Pocheon strain의 병원 성이 49.6%로 가장 높았고, 익산과 화순에서 채집된 S. carpocapsae Iksan strain과 S. monticolum Hwasun strain은 각각 20.4%, 12.0%의 낮은 치사율을 나타 내었다. 실내 병원성 검정에서 병원성이 가장 높았던 S. carpocapsae Pocheon strain의 농 도별 병원성 검정 결과 농도가 높을수록 치사율이 높아졌지만 50%를 넘지 않았다. 그러나 이화명나방 유충에 대한 야외실험 결과, S. carpocapsea Iksan 처리구에서 무처리 대비 80.6%의 높은 방제가를 나타내었으며 B. bassiana 처리구와 H. bacteriophora 처리구에서 각각 61.2%, 58.3%의 방제가를 나타내었다.

For the environment-friendly control of beet armyworm, Spodoptera exigua, in spring onion fields, we have examined an alternative application method. Twenty-five insecticides registered for spring onion were tested for control effect against the beet armyworm in the laboratory, then the best 9 chemical and a single biological insecticides were selected and compared with 2 new isolates of Bacillus thuringiensis in a polyvinyl house. After that, 4 chemical and 3 B. thuringiensis treatments were used in the field for the control of beet armyworm in the spring onion. Two application methods are used: one is triple treatments with the same chemical and the other is alternative application with different chemicals and B. thuringiensis for 7 days intervals. Indoxacarb WP – chlorfluazuron EC – B.t. var. kurstaki CAB141 and indoxacarb WP – methoxyfenozide + spinosad SC – Chlorfluazuron EC – B.t. var. aizawai CAB109, B.t. var. kurstaki CAB141 showed greater than 78% mortality of beet armyworm larvae and greater than 43% damage decrease in spring onions infested by beet armyworm. These results showed that alternative applications had higher control effect than any other applications. It was suggested that alternative applications with microbial biological agents such as B. thuringiensis might minimize the development of insecticide resistance and might be used as the environment-friendly control of the beet armyworm.

배추좀나방은 비닐하우스 등 시설재배가 늘어남에 따라 십자화과 채소의 연중재배가 이루어지면서 경제적인 피해가 심한 농작물 해충 중 하나이다. 이 해충은 세대기간이 짧고 화학농약의 집중살포로 인해 저항성이 빠르게 발달 되어 방제가 어렵고 미생물제제인 B.t에 대해서도 저항성이 보고되고 있는 실 정이다. 최근 이러한 문제해결과 친환경적 방제를 위하여 천적의 이용이 증가 하고 있지만, 천적과 미생물제제를 동시에 이용하여 종합적 해충방제를 하기 위한 시도들과 그에 따른 방제효과에 대한 정보들이 미흡한 실정이다. 따라서 배추좀나방 방제를 위해 이용되는 천적인 조명알벌의 기생율과 국내에서 시 판중인 B.t 약제의 혼합 처리시 방제효과에 대한 기초 자료를 얻고자 실험을 실시하였다. 배추좀나방에 이용되고 있는 천적 중 알에 기생하는 조명알벌과 B.t 생물농 약 T제품을 투입시기를 달리하여 처리 후 조명알벌의 기생율과 배추좀나방 유충 생존율, 피해엽수 등을 조사하여 각각의 처리와의 방제효과를 비교하고 자 하였다. B.t 약제를 처리 후 천적을 투입하였을 때 이전보다 좋은 방제효과 를 나타내었는데, 이와같이 혼합처리를 통한 배추좀나방 모든 발육단계의 동 시방제를 통하여 보다 효과적이고 안정적인 친환경방제를 할 수 있을 것으로 기대된다. 추후 대표적인 농업해충인 파밤나방과 거세미나방에 대한 조명알벌 의 기생율과 배추 포장실험을 통하여 보다 효과적인 방제방법을 연구할 계획 이다.

Road-map for the environmental friendly integrated pest management (IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer’s field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.

For the development of friendly environmental control of the beet armyworm, Spodoptera exigua that is too hard to control in the field, 25 insecticides were chosen from 58 registered to the beet armyworm, and bioassayed. There are 12 insecticides with neurotoxical activities, 10 with insect growth regulators and 3 Bacillus thuringiensis products. Among 12 insecticides with neurotoxical activities, mortality of S. exigua was 100% with emamectin benzoate (EC) and indoxacarb (WP) within 3 and 5 days after application, respectively. Otherwise, WG and SC of indoxacarb, Indoxacarb + etofenprox (WP) and pyridalyl (EW) were showed up to 91%. Methoxyfenozide + spinosad (SC) was better than any other insect growth regulator as 100% mortality within 3 days after application. And methoxyfenozide (WP), tebufenozide (WP) and methoxyfenozide (SC) were 92% by 5 days. However, 3 kinds of B. thuringiensis products were showed under 35% mortality within 5 days from first spray.

Bioassay of mosquito, Culex pipiens molestus, larva was investigated by several environment-friendly insecticides. These insecticides were Novaluron as chitin synthesis inhibitor, Metho-xyfenozide as ecdysone agonist, Pyriproxyfen as juvenile hormone mimic, and Spiromesifen as lipid biosynthesis inhibitor. The 50% lethal concentration (LC₅₀) of these insecticides were 0.00039, 0.07193, 0.65006 and 0.04839 ppm, respectively. Novaluron has lower concentration than any other insecticide. To determine the treatment time against larval stages, insecticides were applied to different larval stages of C. pipiens molestus. Mortality ratios of mosquito larva treated with Novaluron were 100.0, 84.5, 71.0 and 48.5% on 2, 4, 7 and 10 days after hatching from eggs, respectively. Otherwise, with the other insecticides, mortality ratios were under 80% with 2 days old larva. When exposure periods were tested to 3 or 4 days old larva against 4 insecticides, at least 3 hours were needed to 100% control effect against Novaluron, and over 12 hours with other insecticides.