Ovicidal properties of flucycloxuron on Colorado potato beetle (Leptinotarsa decemlineata Say).

摘要

The ovicidal activity of the insect growth regulator flucycloxuron in Colorado potato beetle was evaluated. Contact and transovarian methods of application were used in the experiments. In the first set of experiments, the egg mass collected from a laboratory colony was dipped in water solutions of the insecticide (0.1, 0.05 and 0.003 g a.s./litre) placed in petri dishes and incubated at 24 degrees C for 5 days. To study of the transovarian activity, 10 females were placed in a glass container with flucycloxuron-treated potato foliage using the same concentration of insecticide as in the contact method. The eggs laid by beetles were collected daily, placed in petri dishes, and incubated. The number of larvae hatching was recorded after 5 days. The ovicidal action of flucycloxuron was dependent on the method used. The transovarian application markedly reduced the hatching of larvae compared to the contact method. The larvae failed to hatch after 72 h of female feeding with all studied concentrations of the insecticide. In the contact method, hatching of eggs exposed to insecticide varied from 50 to 89% depending on the rate of the insecticide and age of eggs. The average control of hatching was 88%.