用ELISA方法定量评价食虫沟瘤蛛对稻飞虱的捕食作用(英文)

对捕食性节肢动物的捕食作用进行评价是害虫生物防治研究的一个重要内容。本文利用酶联免疫吸附试验（ＥＬＩＳＡ）定量评价了食虫沟瘤蛛对稻飞虱的捕食作用。结果表明，方法特异性完全符合试验要求；食虫沟瘤蛛在捕食３头３－５龄白背飞虱或褐飞虱若虫后的检出期分别为９６小时和１２０小时；在早稻田中，捕食性天敌对白背飞虱和褐飞虱的阳性反应率分别为１９．０５％－４７．３４％和１９．０５％－６６．６７％，在飞虱密度较低时，捕食性天敌仍表现出较高的阳性率；捕食量随飞虱密度的增加而增加，但捕食率下降。捕食性节肢动物是调节褐飞虱种群动态的重要因子之一。

QUANTIFYING PREDATION BY UMMELIATA INSEC-TICEPS BOES. ET STR. (ARANEAE:LINYPHIIDAE) ON RICE PLANTHOPPERS USING ELISA

An enzyme-linked immunosorbent assay (ELISA) has been developed to quantify predation by Ummeliata insecticeps Boes. et Sir. on rice planthoppers in paddy fields in Dasha Township, Guangdong Province. The assay was completely specific for rice planthopper materials. The detection periods for antigens after an adult of U. insecticeps had fed on three 3-5th instar nymphs of white-back planthopper (WBPH), Sogatella furcifera (Horvath), and brown planthopper (BPH), Nilaparvata lugens (Stal), at room temperature were 96 h and 120 h, respectively. The proportion of individual species of predators scoring positive ranged from 19. 05% to 47. 34% for WBPH, and from 9. 25% to 66. 67% for BPH in the early rice season. Although the numbers of the rice planthoppers consumed by U. insecticeps increased with increasing prey densities, the predation rates declined. When rice planthopper densities were low, the predation rates were relatively high. This kind of predation can explain why the rice planthoppers have never reached outbreak levels in rice fields in Dasha Township since 1973.