栗苞蚜的生活习性及其防治对策

为了对栗苞蚜Moritziella castaneivora Miyazaki进行有效监控,控制其蔓延及制定合理的防治策略,通过林间调查及室内观察研究栗苞蚜对日本栗的为害、主要生活习性和天敌对其捕食行为。结果表明,栗苞蚜对银寄和筑波为害炸苞率分别达(7.4±6.0)%和(8.6±5.5)%;4龄若蚜的耐饥力强于成蚜,二者离开寄主20 h后可分别存活50%和13%,且1龄若蚜迁移力明显强于成蚜;栗苞蚜卵在20:00的孵化率明显高于8:00和14:00。龟纹瓢虫、黑襟毛瓢虫、七星瓢虫和草蛉对栗苞蚜卵具有较强的捕食能力,龟纹瓢虫平均捕食栗苞蚜卵量约为43粒/h,平均取食1个卵为10.1 s,搜寻速率为8.5粒/min。此外,研究表明初春施用石硫合剂可有效减少虫口基数,防止当年栗苞蚜大发生。

Life habits of Moritziella castaneivora (Hemiptera: Phylloxeridae) and its control measures

In order to effectively monitor and manage Moritziella castaneivora, its damage characteristics on Castanea crenata, life habits and predatory behavior were studied through field investigation and indoor observation. The results indicated that the rate of burst fruits of two breeds of Japanese chestnut (Yinji and Zhubo) added up to (7.4±6.0) and (8.6±5.5)% in non-chemical control areas, respectively. The starvation-tolerance capacity of 4th instar nymphs of M. castaneivora was stronger than adults, and the survival rate was 50% and 13% after 20 h without host plants, respectively, and the dispersion ability of the 1st instar nymph was stronger than the adult's. The hatching rates of M. castaneivora were higher at 20:00 than at 8:00 and 14:00. In addition, the predators, such as Propylaea japonica, Scymnus (Neopullus) hoffmanni, Coccinella septempanctata and Chrysopa sp., had strong predation ability against M. castaneivor. The number of preyed eggs, handling time for eggs and the searching rate of P. japonica were 43 eggs per hour and 8.5 eggs per minute, respectively. The study also suggested that it could reduce the number of M. castaneivora and eggs through spraying lime sulfur in the early spring season.