安徽桐城稻水象甲发生规律与治理措施

Occurrence Law and Management Measures of Rice Water Weevil Lissorhoptrus Oryzophilus Kuschel in Tongcheng, Anhui Province

2001年5月,在双季稻北缘地区安徽省桐城市发现检疫性害虫稻水象甲后,开展了稻水象甲发生规律和治理措施的研究,主要结果为①稻水象甲在桐城的寄主是水稻,其他禾本科植物稗草、李氏禾、狼尾草和雀麦只是偶然寄主。②在桐城,稻水象甲1年发生1代,以成虫越冬。越冬成虫初见期在3月下旬,早稻秧苗揭膜后即可为害,随早稻移栽向大田扩散。5月中旬为早稻大田成虫盛发期,田间成虫高峰期约20 d。第1代幼虫5月底初见,6月中旬大量转株为害,6月中旬后期陆续化蛹。第1代成虫于7月上旬始见,先集中于双季晚稻(双晚)秧田为害,随双晚移栽,分散到大田为害,田间终见期在8月中下旬。③稻水象甲虫卵产于稻苗基部叶鞘,每鞘卵量3～4粒。稻水象甲在双季早、晚稻大田初期,由田边向田中逐渐扩散。该虫在田间成虫激增期和减退期为聚集分布,在田间虫量高峰期呈随机分布。④成虫在有水饥饿和无水饥饿情况下,平均存活17.1,4.2 d;成虫平均寿命为56.5 d。⑤桐城稻水象甲与我国北方单季稻和南方典型双季稻区的稻水象甲相比,发生代次和消长规律略有不同。⑥通过人为控制,能够减缓稻水象甲的扩散速度。并提出了以植物检疫和农业防治为基础,适期开展药剂防治的综合治理措施。

In May,2001 quarantine insect——Lissorhoptrus oryzophilus Kuschel was found in the North edge of double-cropping rice in Tongcheng City,Anhui Province.The main results were obtained through the investigation of occurrence principle of Lissorhoptrus oryzophilus Kuschel.First,the host plants of Lissorhoptrus oryzophilus Kuschel include rice,barnyard-grass,common cutgrass,pennisetum and brome in Tongcheng.The gramineous plants were only accidental host plants except rice.Second,Lissorhoptrus oryzophilus Kuschel infested one generation in one year in Tongcheng,and overwintered through adults.The beginning time of overwintering adults is in late March.They make damage after early rice seedlings remove membrane,and diffuse towards field with transplanting of early rice.The adult peak of early rice appears in the mid-May,and the period is about twenty days.The one generation larvaes appear at the end of May,become damage in the mid-June,pupate in succession in the late mid-June.The appearing stage of one generation adults is in the first ten days of July,and the disappearing stage is in middle to late August.Third,the eggs of Lissorhoptrus oryzophilus Kuschel are laid masses on the leaf sheath of rice base.Each leaf sheath lays 3～4 eggs.Lissorhoptrus oryzophilus Kuschel diffuses from the edge to the middle of field gradually at the inital stage of early and late double-cropping rice.The space distribution was aggregation during the explosion period and reducement period of adults.The fourth,if adult and hungry pests are provided water,the average life expectancy will be 17.1 d.However the rate will drop to 4.2 d without water.According to the observation,the average life expectancy is 56.5 d.The fifth,compared with the single season rice in northern China and typical double-cropping rice in southern district in China,the occurrence principle of generation and ups and downs of Lissorhoptrus Oryzophilus Kuschel is slightly different.The sixth,the proliferation of speed of Lissorhoptrus Oryzophilus Kuschel can slow down through artificial control,but its range continued expansion.The article advocated a comprehensive management approach to carry out chemical control in suitable period which is on the base of plant quarantine and agricultural control.