ISHS Acta Horticulturae 558: I International Symposium on Litchi and Longan
CHLORPYRIFOS AND CYPERMETHRIN FOR THE CONTROL OF LITCHI STINK BUG (TESSARATOMA PAPILLOSA) |
| Authors: | X.N. Zeng, D. Deng, J.M. Wang |
| Keywords: | control, knockdown, susceptibility |
| Abstract:
For finding alternatives to the long used trichlorphon, mixture of chlorpyrifos and cypermethrin (10:1) was tested against adults and nymphs of litchi stink bug. The mixture was highly effective against the overwintered adults. Treatment with the mixture at a concentration as low as 138 ppm caused 100% mortality after 7 days compared to 1125 ppm trichlorphon. Although the mixture caused less mortality than trichlorphon on the first day, it gave 100% knockdown of the adults. They were severely affected and lost their ability to feed, fly and walk and were left with trembling antennae, wings and legs. The results from residual tests indicated that the mixture at 550 ppm rate remained active for a longer time although the overwintered adults were easily killed by immediate contact with leaves treated with trichlorphon. Similar results were obtained with early instar nymphs. However, trichlorphon provided lower mortality of the early instar nymphs than of the overwintered adults, while the mixture insecticide was slightly better. This might imply that there are differences in susceptibility to insecticides between nymphs and adults. | |
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