Control methods of Populus tomentosa pests

The larvae of Populus tomentosa, Populus tomentosa and holly were used as nests to damage host plants, and the damaged leaves showed yellow withered spots at the beginning, and then the whole leaves fell off. Silk spinning binds the leaves and the fallen leaves together, so that the leaves can not be extended, the growth and development is seriously affected, and the whole plant dies when the damage is serious.

Shanghai has 3 to 4 generations a year, and the times overlap seriously; in the vertical year, March activity, pupation begins in mid-April, Eclosion begins in late April, the first generation larvae appear in early May, the first generation begins to pupate in early June, the first generation adults emerge in mid-June, and oviposition occurs in late June. At the same time, the second generation larvae begin to appear, pupate in the middle of July, and the second generation adults appear in late July. The third generation larvae appeared in early August, pupated in mid-August, the third generation adults began to Eclosion in late August, spawned in early September, overwintering larvae appeared in mid-September, and entered the overwintering stage in mid-October. The larvae of the 1st and 2nd instar feed on the mesophyll, and after the 3rd instar, they spin silk to make a nest and feed in it. The adults are hidden during the day and active in the evening. Their flying ability is weak and their phototaxis is not strong.

Control methods: during the period from hatching to 2nd instar damage of larvae, 20% Chongwu 1000 × 2000 liquid and 4.5% cypermethrin 1500 times solution were sprayed.