The Resistance, Cross Control of Diamondback Resistance, and Chemical Moth in Taiwan

In order to improve the chemical control of diamondback moth, Plutella xylostella (L), in Taiwan, the Taiwan Agricultural Research Institute organized in 1980 a program aimed at analyzing the insecticide resistance and mode of action. After almost five years of study, we have gathered information on the sampling method, resistance, cross resistance, the mode of insecticide action, and the efficacy of the newest experimental insecticides. Over an area of five thousand hectares, a mixture of five populations from separate fields is needed to test insecticide resistance accurately. The insect develops resistance quickly to almost all insecticides, and of eight tested insecticides the quickest response was recorded to carbofuran, profenofos, and fenvalerate. Cross resistance between organophosphorus compounds and synthetic pyrethroids was detected; carbofuran resistance was independent of that of other insecticides. The resistance impact not only demonstrated the initial but also the residual effectiveness of all insecticides. Several insecticides with minimal resistance problem (mevinphos, phenthoate, cyanofenphos, methamidophos and cartap) were identified and were very helpful in adjusting the diamondback moth control scheme.