Feasibility Studies on the Biological Control by Augmentation and Conservation of Natural Enemies of Rice Paddy

수도해충(水稻害蟲) 천적(天敵)의 보호(保護) 및 이용(利用)에 관(關)한 기초(基礎) 연구(硏究)

The purpose of this study was to establish the intergrated control of rice insect pests. Specific objectives were to reveal the diversity of natural enemies in rice field environment, to obtain basic informations of their population dynamics, and to screen the selective insecticides for the conservation of natural enemies. The results of the study were as follows. 1. In numbers of species and in numbers of each species of parasitic Hymenoptera of rice insect pests were more diverse and abundant in rice paddy leeves and banks than paddy fields. Braconid Mymarid and pteromalid were predominated in the field and their population was high during early August to mid September. 2. Of the predatory spiders, Pirata subpiraticus was the largest in number and amounted to 72% of the total, Gnatonarium dentatum, Pachygnatha clerki and Clubiona japonicola were the next. It was also found that P. subpiraticus had three generations in a year. 3. Hence the activities of the predatory spider species and parasitic Hymenoptera were high in early to mid August and September, it would be better promising to avoid chemical applications at this time of periods as possible. 4. The relative toxicity of several insecticides which have been used for the control of brown plant hopper (BPH) showed that P. subpiraticus was 1.1-73.1 times higher than BPH and G. dentatum to P. subpiraticus was 1.1-73.1 times, respectively. 5. Three conventional insecticides, Padan, Diazinon and Carbofuran were screened for toxicity to predatory spider species. The insecticides deffered in their toxicity to the predators. However, Padan was appeared to be the least toxic to the predators.

수도해충(水稻害蟲) 천적(天敵)의 개발(開發)과 이들의 계절적(季節的) 밀도변동상황(密度變動狀況)을 파악(把握)하고 천적(天敵)에 안전(安全)한 약제철(藥劑撤) 포(布) 시기(時期)를 구명(究明)하는 한편 선택성(選擇性) 약제(藥劑)를 선발(選拔)하여 이들 천적(天敵)을 보호증식(保護增植)할 수 있는 종합방제확립(綜合防除確立)의 기초자료(基礎資料)를 얻고저 본(本) 시험(試驗)을 실시(實施)한 결과(結果) 마음과 같은 결론(結論)을 얻었다. 1. 논보다 논뚝이 보다 천적(天敵)이 풍부(豊富)하고 다양(多樣)하였으며 가장 많은 종류(種類)로서는 Braconid, Mymarid, Pteromalid등이었다. 이들 기생봉(寄生蜂)의 활동(活動)이 가장 활발(活發)한 시기(時期)는 8하(下)~9중순(中旬)이었다. 2. 논에 누식(累息)하는 포식성천적(捕食性天敵)인 거미로 Pirata subpiratious (황산적 거미)가 전체(全體) 논거마의 72%를 차지하고 있었으며 1년(年)에 3회(回) 발생(發生)하고 있었다. 그 다음으로는 Gnatonarium dentatum(황갈애접시거미), Pachygnatha clerki(턱거미), Clubiona Japonicola(노랑염낭거미)등이 많았다. 3. 기생봉(寄生蜂)과 포식(捕食)거미의 활동(活動)이 가장 활발(活發)한 시기(時期)는 8상(上)~중순(中旬)과 9상(上)~중순(中旬)이 었으며 가급적(可級的)이 시기(時期)를 피하(避)여 방제(防除)하는 것이 바람직하다. 4. 현재(現在) 사용(使用)하고 있는 수도용(水稻用) 살충제(殺蟲劑)들의 선택독성(選擇毒性)을 조사(調査)한 결과(結果) 벼멸구 보다 황산적거미가 3.1~125.5배(倍), 황산적거미 보다 황갈애접시거미가 1.1~73.1배(倍)나 더 강(强)한 경향(傾向)을 나타내었다. 5. Padan, Oiazinon, Carbofuran등(等) 3 종(種)의 약제중(藥劑中) 실제(實際) 단장(圃場)에서 논거미 밀도(密度)에 미치는 영향(影響)은 Padan이 비교적(比較的) 적은 편(便)이었다.