The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.

To mitigate the intrusion of insect pests, behavioral modifications using repellents are commonly employed. Among their active ingredients, plant essential oils have gained prominence as safer alternatives to synthetic repellents. However, the absence of rigorous scientific efficacy testing have been undermined the reliability of these essential oil based repellent products. Previous studies have highlighted that the observed repellency in bioassays are strongly influenced by the testing environment. Our research introduces three distinct laboratory-scaled repellency test methods – spatial repellency, choice repellency in a closed and opened environment – to evaluate prevalent insect repellent products. Notably, we observed significant variations in repellency percentages among products. The most effective product from each method was identified, and its active ingredients were analyzed both quantitatively and qualitatively, by GC-MS analyses. To determine the applicability of these methods in selecting active ingredient concentrations, individual active ingredient components underwent dose-response testing. Our findings suggest that, when selected appropriately, these three methods can be applied for the development and evaluation of potent essential oil based repellent products.

초음파 모기 기피 장치 ‘모스 윈드솔루션(Mos windsolution)’의 성능을 실내에서 평가하였다. 해당 제품은 120Hz~1.2MHz 사이의 주파수를 가진 초음파를 발생시켜 모기가 기피하도록 유도하는 기능을 갖고 있다. 기기의 성능 평가를 위하여 선택적 실험과 비선택적 실험을 실시하였다. 선택적 실험은 2m의 PVC 파이프 양 끝에 15cm cube 형태의 실험 케이지를 연결하고, 그 옆면에 쥐를 한 마리씩 구속하였다. 처리구 쪽에 모스 윈드솔루션을 가동시켜 초음파가 발생하도록 놓은 후 파이프 중앙에 흰줄숲모기(Aedes albopictus)를 방사시켰고 1시간 뒤 양 케이지를 밀봉, 냉동시켜 유입된 흰줄숲모기의 성별과 수를 파악했다. 비선택적 실험은 150x200x150cm의 모기장 안에 상부만 열린 아크릴 케이지를 넣고, 아크릴 케이지 내부에 철망 뚜껑이 있는 용기에 담긴 쥐를 넣어두었다. 처리구 쪽에는 모스 윈드솔루션을 가동시켜 놓았다. 모기장에 흰줄숲모기를 방사시키고, 시간당 아크릴 케이지에 유입된 모기의 수를 파악하였다. 그 결과 두 실험 모두에서 모스 윈드솔루션이 대조구 대비 최대 80%의 모기 기피 효과를 보였음을 확인할 수 있었다.