小蛀果斑螟的发生与防治技术研究

Occurrence of Assara exiguella and its control

通过对小蛀果斑螟Assaraexiguella(Caradja)的室内饲养观察和田间调查、防治试验.结果表明:在夏秋季,卵期(4.5±0.5)d,幼虫期(14.0±2.0)d,蛹期(8.0±1.0)d,产卵前期(2.5±0.5)d,完成1个世代(27.5±3.5)d,成虫寿命(4.0±1.5)d.卵散产,幼虫5龄,蛀果后不转果危害,成虫无趋光性.在粤东栗区1年发生7个世代,以幼虫在落地栗壳、树干等处越冬.第1～2代田间发生量极少,第3～6代幼虫取食果柄、蛀食栗果,造成严重危害.栗树的不同品种及其结果特性、耕作制度及降雨量是影响该虫发生量的主要因素.毒死蜱、杀虫单等多种杀虫剂对该虫有良好的防治效果;冬春季做好清园、剪去无经济价值的第2季花果、田间间种豆科作物、适期施药等综合防治措施能有效地控制该虫的危害.

Assara exiguella (Caradja) is a insect pest of chestnut. The results from experiment showed that the egg development duration of A.exiguella was (4.5±0.5) days, (14.0±2.0) days for larvae development duration in five instars, (8.0±1.0) days for its pupa development duration, (2.5±0.5) days for its adult preoviposition duration, (27.5±3.5) days for completing its one generation and there were 7 generations in east Guangdong Province, and that the adult's longevity was (4.0±1.5) days and the eggs laid was in sparse. The feeding behavior of the pest was observed that the larvae did not remove to feed another fruit after it bored into the fruit. The larvae overwintered in the fallen chestnut shells and trunks. The population of the insect pests was lower in the 1^(st) and 2^(nd) generation, while the larvae damaged the fruit stalks and fruits seriously. The varieties of chestnut, fruiting characteristics, cultivation system and rainfall were the main factors influencing the population of the pest. In farming practice, the measurements such as cleaning up the chestnut orchard in winter and spring, removing the second layer of flowers and the fruits without economics and intercropping with leguminaceous crops were good effective integrated control of the pest. And the insecticides chlorpyrifos and molosultup were used to control the pest in chestnut farming.