Studies On The Biology And Ecology And Control Teconologies Of Olethreutes Leucaspis Meyrick

Olethreutes leucaspis Meyrick falls under the class of Olethreutinae of Lepidoptera. The insect happen at regions producing litchi and longan in China, and it does harm to tender leaf and young shoot with larva mainly influencing photosynthesis and tendency normal to grow. It is serious especially in the period of treetip in summer and autumn, because it can influence bearing base shoots forming of next year directly. Now, the quantity of Olethreutes leucaspis Meyrick become more than 85% of all the leaf rollers which are harmful to litchi and longan, It have already become the advantage population of leaf rollers which has endangered litchies , longan. In this paper, the biology and ecology of Olethreutes leucaspis Meyrick were studied more comprehensively. The habits of its life were observed and the regular rule of happening was found out. In this result, offer the effective control measures. The main result of study is as follows:1) Biology of Olethreutes leucaspis Meyrick: Olethreutes leucaspis Meyrick have 10 generations in one year in the canopy(danzhou,hainan), and generation overlap. The larva have six instars. It conceals in the leaf at all larva stage, and the old larva makes triangular leafy bract and takes pupa among them on more older leaf in nearby. The peak period of eclosion is pm2:00~pm4:00, 1~2 days before ovulation, The adult lay eggs among the compound leaf or small leaf chink that has already sprouted on the tip bud, or among the veins of the small leaf.2) Ecology of Olethreutes leucaspis Meyrick: Five kinds of accumulation degree index were used for the matching judge of the space distribution model kept by the mentioned larva. The result showed that the space distribution coincided with that of the accumulated model in the litchi orchard, and the degree of aggregation intensity strengthen gradually with the density of larva. The index of population trend at five tempratures of Olethreutes leucaspis Meyrick from high to low is 24℃(60.80)>28℃(53.76)>32(30.24)>20℃(30.00)>16℃(26.84), it shows that the Olethreutes leucaspis Meyrick likes higher temperature, and the suitable growth temperature range is 24~30℃. The humidity has a certain influence to the growth of Olethreutes leucaspis Meyrick too, The index of population trend at five relative humiditys of...