甘蔗异背长蝽生物学的观察

OBSERVATION OF THE BIOLOGY OF CAVELERIUS SACCHARIVOR US (OKAJIMA)

甘蔗异背长蝽是甘蔗的重要害虫,在江西泰和县一年发生完整的二代,部分三代,主要以卵在蔗蔸、土表层、枯鞘残茎和蔗种叶鞘内越冬,尚有少部分成虫在宿根蔗蔸和枯鞘叶中过冬。全年有两个为害严重期,第一次在五六月甘蔗苗期,第二次在八九月甘蔗伸长期。一代若虫孵化较整齐,且低龄若虫集中在心叶内吸食,是药剂防治的关键时期。成虫多群集在蔗株下部枯鞘与蔗茎间隙内栖息、取食和交配。卵成块产于叶鞘边缘内侧,以叶鞘抱茎松紧度适中的叶位分布最多,二代成虫9月间产的卵,当年可以孵化并发育为三代成虫越冬;10月初以后产的卵,当年不再孵化而滞育越冬。

Cavelerius saccharivorus (Okajima) is one of the major pests in sugarcane. Most of the bugs have 2 generations, partly 3 generations each year in Taihe County, Jiangxi Province. They hibernate mainly in the egg stage in the sugarcane root systems, in surface soil and in the withered leaf sheathes, remained stems and the leaf sheathes of the regenerating sugarcane stems, partly in adult stage in the old sugarcane root systems and in the dead leaf sheathes of sugarcanes.In one year, sugarcanes are harmed seriously by the bugs first in the period from May to June, the seedling stage of the plants, which mainly affects the yield, second in the period from August to September, the extending stage of the plants, which mainly reduces the sugar content.Eggs of the first generation hatch rather regularly, and the younger nymphae suck the leaf juice gregariously in the innermost leaves of sugarcanes, and it is the key period for chemical control. Most of the adults stay, feed and mate in groups in the gaps between the stems and withered leaf sheathes in the lower part of the sugarcanes. The eggs are oviposited in masses on the inner edges of the leaf sheathes, and distributed mostly on the leaves that hold the stems in moderate tightness.Of eggs of the second generation, those oviposited in September may hatch and develop to hibernatant adults of the next generation in the same year, and the other eggs oviposited after October don't hatch but hibernate directly.