湖南省稻秆潜蝇发生规律及防治药剂筛选

为有效防控稻秆潜蝇Chlorops oryzae的发生危害,于2017—2018年在湖南省11个县(市)定点系统调查稻秆潜蝇的寄主、田间发育进度、发生世代数及产卵选择性,并进行3种常用药剂的田间防治效果试验。结果表明,稻秆潜蝇的夏寄主有水稻、游草和稗,越冬寄主有看麦娘和冬小麦。在湖南省1年发生5代,即早稻上发生完整的第1代,中稻上完成第2、3代,晚稻上完成第4代,在看麦娘上完成第5代(越冬代)。不同水稻品种上稻秆潜蝇总着卵量差异显著,其中在丰两优6348品种上最多,为120.5粒,同一生育期内不同水稻品种上稻秆潜蝇着卵量之间差异显著,同一品种不同生育期的稻秆潜蝇着卵量之间有差异;不同水稻品种上稻秆潜蝇初孵幼虫平均钻蛀成功率之间差异显著,除破口初期,同一生育期内不同水稻品种上稻秆潜蝇初孵幼虫钻蛀成功率之间差异显著。所有供试药剂的中稻晒田前施药的防治效果均显著高于晒田后的防治效果;在晒田前施药中,0.1%呋虫胺颗粒剂的防治效果最好,在黄土店镇和朱亭镇的防治效果分别为97.6%和93.6%,显著优于70%吡虫啉和40%毒死蜱的防治效果。

Occurrence and fungicides screening of the rice stem maggot Chlorops oryzae in Hunan Province

In order to effectively prevent and control of the rice stem maggot, Chlorops oryzae, the host plants, field development progress, generations and oviposition selectivity of RSM in 11 cities and counties of Hunan Province were systematically investigated from 2017 to 2018, and the field control effects of three commonly pesticides were tested. The results showed that Oryza sativa, Leersia hexandra and Echinochloa crusgalli were the summer host plants of C. oryzae, while Amygdalus oryzae and Triticum aestivum were overwintering host plants. Moreover, it was estimated that five generations of C. oryzae could occur per year in Hunan. The first generation was completed on early rice; the second and third generations were completed on middle rice; the fourth generation was completed on late rice, and the fifth generation (overwintering generation) was completed on A. oryzae. Furthermore, there were significant differences in the total number of eggs of C. oryzae among different rice cultivars. The largest number of eggs (120.5) was laid on cultivar Fengliangyou 6348. There were remarkable differences in the number of eggs of C. oryzae on different rice cultivars during the same growth period, or on the same cultivar during different growth periods. There were significant differences in the boring success rate of neonates among different rice cultivars. There were significant differences in the boring success rate of neonates on different rice cultivars during the same growth period, except for the early break stage. In addition, the control effects of all tested pesticides were significantly better when applied on the middle rice before field drying than after field drying. Meanwhile, 0.1% dinotefuran had the best control effect in the field before paddy field drying (97.6% in Huangtudian Town and 93.6% in Zhuting Town, respectively), which were significantly better than those of imidacloprid (70%) and chlorpyrifos (40%).