Bionomics and Control of Homona issikii
Xu Deqin Qin Shengwu (Forestry School of Zhejiang)
Homona issikii Yasudas is an important insect pest of the Cryptomeria fortunei and C. japonica in East China and Taiwan Province. It has two generations per year in Wencheng county, Zhejiang province. Winter is passed as newly larvae in the inner of leaves of dying down branches to be eaten. The larvae begin to be active early April next year. The adult moths begin to appear in late May. It hides during the day in shaded of trees, mating and oviposition take place by day and night now and then. The eggs are laid masses on the surface of shoot and the base of leaves. Each female moth lays 43-254 eggs. The newly hatched larvae usually feed leaf flesh and only the epidermis will remain. Larvae over 3 instars web several shoot to form temporary nest, and feed on the leaves and epidermis of shoot by their nests. The larval stage has five instars. The mature larva pupates in the temporary nest. There are a number of natural enemies attacking this insect. Among then the important are Macrocentrus sp. and Beauveria bassiana. The result of experiments showed that Decamefhrin, Tamaron, Trichlorphon, Dichlorphos, Omethoate, Beauveria bassiana were very effective for the control of the larvae.