几种化学农药对稻田优势种蜘蛛杀伤力的研究

用５种化学农药对稻田优势种蜘蛛杀伤力的盆栽与田间进行测试。结果表明，５种化学农药对稻田４种优势种蜘蛛都有较大的杀伤力，总的杀伤率达６２．１％－９１．７％，盆栽施药比田间施药对蜘蛛的杀伤力大。田间试验结果应当比较符合实际；田间试验对照组蛛虫减退的民政部进一步说明，蜘蛛对目标害虫具有良好的控制作用，在晚稻后期，如果蛛虫比在１：５以下，用不着使用化学农药防治。

KILLING CAPABILITY OF SOME PESTICIDES ON DOMINANT SPECIES SPIDERS IN RICE EIELDS

This paper reports the testing results of mortality of five chemical pesticides on dominant species spielers in the rice fields. The results show that there is a relative high mortality of five chemical pesticides on four dominant spiders, and the total killing rate reaches 62. 1 - 91. 7%. The mortality on spiders of applying pesticides on potting rice is higher than that of on field rice. The result of the test on field rice is supposed to be accorded with the practice. The decrease of spiders and insects in the con-troled groups in the test on field rice can explain more clearly that spiders play a effectively controling role on their target insects. It's unnecessary to apply chemical pesticides to control insects when the rale of spiders to insects is less than one to five is the later stage of late rice.