Abstract
The effect of NeemAzal-T/S was tested by leaf disk method on fecundity, egg mortality, and preference of twospotted spider mite, Tetranychus urticae and its predator mite, Amblyseius womersleyi in the laboratory. Mortalities of T. urticae and A. womersleyi adults were 97.7% and 20.0%, in 100ppm treatment at 72 h after application, respectively. The mean number of eggs laid per T. urticae female adult were 0.0 and 18.5, and those of A. womersleyi were 1.6 and 2.9 at 100 ppm and 0 ppm concentrations, respectively. Hatchability of T. urticae eggs treated with 50 and 100 ppm were 52.8%, and 2.5%, respectively, and those of A. womersleyi eggs were 100% and 91.3%, respectively. Choice and no-choice tests revealed that T. urticae female preferred to alight and oviposit on untreated bean leaf disk with 13.8 to 18.2 eggs per female. In contrast, A. womersleyi female preferred on treated or untreated bean leaf equally. There was no significant differences in the number of consumption of T. urticae eggs by A. womersleyi on treated and untreated bean leaves, except 200 ppm. These results indicate that NeemAzal-TIS is highly toxic to T. urticae, and is less toxic to A. womersleyi. It may be concluded with these results that NeemAzal-T/S could be incorporated into integrated T. urticae management system.
점박이응애(Tetranychus urticae)와 긴털이리응애(Amblyseius womersleyi)에 대한 NeemAzal-T/S의 농도별 독성을 leaf disk법으로 시험하였다. 점박이응애와 긴털이리응애의 성충살비율은 100ppm에서 각각 97.7%, 20.0%로 나타났다. 점박이응애의 산란수는 100ppm에서 0.0개, 무처리 18.5개 였으며 긴털이리응애는 100ppm과 무처리에서 각각 1.6개, 2.9개였다. 부화율은 50ppm에서 점박이응애 52.8%, 긴털이응애는 100%였으며, 100ppm에서는 각각 2.5%, 91.3%로 점박이응애가 긴털이리응애보다 영향을 많이 받았다. 약제처리유무에 따른 영향은 choice, no-choice 조건에서 시험한 결과 choice조건에서 점박이응애는 약제가 처리된 잎에 전혀 산란하지 않고 약제가 처리되지 않은 잎에만 암컷당 13.8~18.2개 산란하였다. 긴털이응애는 먹이(점박이응애 알)의 약제처리 유무에 관계없이 산란하였다. 또한 긴털이리응애의 포식력에서 choice 조건의 200ppm에서만 차이를 보였을 뿐 다른 농도에서는 먹이의 약제처리 유무에 관계없이 비슷하게 포식하였다.
