田埂留草控制稻飞虱效果及对捕食性天敌多样性影响

为探讨稻田田埂保留杂草控制稻飞虱的效果及对捕食性天敌多样性的影响,以稻田田埂周年性保留杂草为处理,以稻田田埂不保留杂草为对照,对处理区和对照区稻田稻飞虱成若虫、捕食性天敌种类和数量进行系统调查和分析。结果表明,在调查期内(6—10月),田埂留草稻田百丛稻株稻飞虱数量为(891.11±133.12)头,较非留草稻田减少35.31%;田埂留草稻田捕食性天敌隶属5目23科35种,而田埂非留草稻田隶属5目21科33种;田埂非留草稻田捕食性天敌优势种为食虫沟瘤蛛Ummeliata insecticepsBoes.etStr.、拟水狼蛛Pirata subpiraticus Boes.etStr.和黑肩绿盲蝽Cyrtorrhinus livdipennis Reuter,而田埂留草后优势种为食虫沟瘤蛛U.insecticeps、草间小黑蛛Erigonidium graminicolum(Sundevall)、拟水狼蛛和拟环纹狼蛛Lycosa pseudoamulata(Bose.etStr.);田埂留草稻田捕食性天敌的个体数量、丰富度、多样性指数分别为(128.89±13.52)、(33.67±0.50)、(4.53±0.04)头/百丛,较田埂非留草稻田分别增加31.96%、25.73%、5.59%,而优势度指数和均匀性指数没有显著变化。研究结果为发展稻田景观多样化控害提供依据。

Effect of retaining grass on rice field ridges on rice planthoppers and the diversity of natural enemies of rice pests in rice fields

To determine the effect of retaining grass on rice ridges on rice planthoppers and the diversity of their predatory natural enemies in rice fields, we compared rice fields with grass to those without grasses. The results indicate that the June to October abundance of rice planthoppers per 100 rice plants in rice fields with grass was 891.11 ± 133.12, 35.31% less than in fields without grass. There were 35 species of predatory natural enemies belonging to 23 families and 5 orders in rice fields with grass compared to 33 species of predatory natural enemies belonging to 21 families and 5 orders in rice fields without grass. The dominant species of predatory natural enemies in fields without grass were Ummeliata insecticeps Boes. et Str., Pirata subpiraticus Boes. et Str. and Cyrtorrhinus livdipennis Reuter, whereas in fields with grass the dominant species were U. insecticeps, Erigonidium graminicolum （Sundevall）, P. Subpiraticus and Lycosa pseudoamulata （ Bose. et Str. ）. The number per 100 rice plants, richness and diversity index of predatory natural enemies in fields with grass were 128.89± 13.52, 33.67± 0. 50 and 4. 53 ±0.04 respectively, which were respectively 31.96% , 25.73% and 5.59% that found in fields without grass. We conclude that maintaining grass on rice field ridges is a potential way to maintain populations of beneficial insects and control rice pests in China.