The control effects of 3% Cypermethrin microcapsule suspension, 1.2% Nicotine-matrine emulsion, 25% Chlorbenzuron wettable powder and 2% Abamectin-bacillus thuringiensis wettable powder against 1-2 instar larvae Ptyomaxia sp. were determined in laboratory. Results showed that, in the range from 5 000 to 100 000 times diluted solution, the mean of death rate among these four pesticide treatments were significantly different, the control effect was highest for Cypermethrin and then followed by Nicotine-matrine, Chlorbenzuron and Abamectin-bacillus thuringiensis. On the tenth day post treatment with 5 000, 10 000, 50 000 times diluted solution of Cypermethrin and 5 000 times diluted solution of Chlorbenzuron, the death rates were among 91.67% -
93.33%,the death rates in the groups that treated with 5 000 times diluted solution of Nicotine-matrine were 87.50%. These three kinds of pesticides of Cypermethrin, Chlorbenzuron and Nicotine-matrine showed potential application prospects for the management of Ptyomaxia sp. in mangrove forest during late March and early April.
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