The effects of some essential oils and Sopophora extract on Frankliniella occidentalis adults, Myzus persicae adults, Plutella xylostella larvae, and Spodoptera exigua larvae were investigated. Insecticidal and phytotoxicity activities of emulsion in water formulations containing the active essential oils as active ingredients under laboratory and pot conditions were also tested. Based on these results, NRS-13 and NRS-24 formulations were selected to further assess as follows; the GC and GC-MS analysis on the active essential oils, the quantity analysis of the major components contained in the formulations, their insecticidal activities under pot and field conditions, and their oral, dermal, skin and eye irritation, and fish toxicities. Thus, the NRS-13 (BaechooSaferTM) and NRS-24 (JindiOutTM) formulations could be considered as insecticides for pest control.
The occurrence pattern of lepidopteran adults in a paddy-upland rotation field and an organic upland field for 8 maize and 7 sorghum varieties was surveyed from May 8 to September 27, 2016. In addition, their damage ratio and the invasive pores by Ostrinia furnacalis larvae as well as harvest yields were monitored. The density of the lepidopteran adults in two fields showed similar pattern, although a little different pattern in Heliothis assulta. The damage ratio of maize and sorghum varieties by O. furnacalis at harvest periods was depended on both varieties and cultivated environments. A middle negative linear correlation was observed in damage ratios vs yields, the number of invasive pores vs yields, and the number of larvae in corn ears vs yields, but there was not a specific correlation between the damage ratio vs the number of invasive pores. These results may be useful for the establishment of a management strategy to control oriental corn borer in paddy-upland rotation or organic upland fields for maize and sorghum.
Occurrence characterization of oriental corn borer, Ostrinia furnacalis, in a paddy-upland rotation field for 8 maize and 7 sorghum varieties was surveyed. In a monitoring study using a pheromone trap carried out from 15 May to 10 September, the density of O. furncalis adults increased rapidly from about 2 weeks after corn planting and reached the highest density at mid June. After that, their density was decreased and increased a little at earlier September. In a survey carried out at harvest period using 8 corn varieties, the damage ratio was Daehakchal (94%), Mibaek 2 (92%), Ilmichal (71%), Eolrukchal 1 (64%), Chalok 4 (54%), Miheukchal (52%), Heugjeom 2 (45%). The number of invasive pore per Ilmichal stem by O. furnacalis larvae was 1.4 and those of the others was less than 1.0. In another survey carried out at harvest period using 7 sorghum varieties, their damage ratios were DS-202 (95%), Moktaksusu (76%), Sodamchal (75%), Nampungchal (67%), Anzunbaengisusu (57%), Donganme (46%), and Hwanggeumchal (34%). The damage of sorghum varieties was much higher and severer than that of corn by O. furnacalis larvae. These results may be useful for the establishment of a management strategy to control oriental corn borer in paddy-upland rotation fields for maize and sorghum.
충해 또는 병충해 관리용 친환경유기농자재로 목록공시된 제품 29종의 배추좀나방과 파밤나방 유충, 복숭아혹진딧물 성충, 꽃노랑총채벌 레 성충에 대한 살충과 섭식저해활성을 분무법과 잎침지법을 이용하여 실내에서 평가하였다. 배추좀나방 유충에 대해 추천농도 분무 또는 잎침지 시 유효성분으로 고삼 추출물 60% 단제(EOIS)와 고삼외 3종 식물 추출물(백부근, 멀구슬나무, 개박하, EIOSm) 및 고삼외 2종 식물추출물 (EOISc)을 함유한 혼합제의 살충력이 우수했다. 하지만 반량 처리 시 그 활성은 50% 이하로 감소되었다. 파밤나방 유충에 대해서는 고삼 60% 단제(EOIS)만이 우수한 살충력을 보였고, 비슷하게 꽃노랑총채벌레 성충에 대해 잎침지 후 24시간과 48시간 노출 시 85%와 95%의 살충력을 나타냈다. 복숭아혹진딧물 성충에 대한 분무시험에서 고삼 외 3종 혼합제(EOISm)와 유채외 2종 혼합제(EOIR)가 93%와 68% 살충력을 보였 는데, 농도를 배량 증가시켜도 살충력은 크게 향상되지 않는 경향을 보였다. 추천농도 잎침지에서는 고삼외 3종 혼합제(EIOSm)만이 100%의 강 한 접촉독성을 나타냈는데, 노출 시간과 농도를 증가시키면 시트로넬라오일외 1종(EOICi)과 유채외 2종 혼합제(EOIR)들의 살충력이 증가하였다. 흥미롭게도 cedar oil 16%(EOICe), 고삼 60% 단제(EOIS), 고삼외 3종 혼합제(EIOSm), 고삼외 2종 혼합제(EOISc), 미생물 89.62%(EOIM), 유 채외 2종 혼합제(EOIR), 식물추출물(EOIPe), 차나무추출물 48%(EOIT)제 등은 파밤나방에 대해 분무처리 시 강한 섭식저해활성을 나타냈다. 또한 배추좀나방 유충에 대해서도 이들 혼합제들 이외에 3종 미생물제들(EOIB, EOIM, EOIBs)과 시트로넬라오일외 1종(EOICi), 겨자외 2종 (EOIMc) 등의 식물 추출물 혼합제들이 70% 이상의 섭식저해활성을 나타냈다. 이상의 결과, 대상 곤충 종 및 유효성분이나 처리량에 따라 살충 력과 섭식저해력이 차이를 보였으나, 전체적으로 고삼추출물외 2-3종 식물추출물을 복합적으로 함유한 혼합제들의 유효력이 우수하게 나타남을 알 수 있었다.