Control methods of yellow poplar silk wild borer in garden ornamental trees

Distribution and damage to the yellow poplar silk borer DiaphaniaperspectalisWalker also known as the yellow poplar black edge borer moth. It belongs to Lepidoptera, Pyralidae. Distributed all over the country. The larvae are harmful to Populus tomentosa, Holly and Euonymus. The insect is sudden, the light ones affect the normal growth, and the heavy ones wither and fall off, resulting in bald branches and death of the young plants.

The morphological characteristics of the adult are about 23 mm in length and 48 mm in wingspan. Except that the leading edge, outer edge, trailing edge and outer edge of the hind wing are black-brown broadband, most of them are covered with white scales and fuchsia flash. In the wide band of the leading edge of the forewing, there is a crescent leukoplakia. The male moth has black hair plexus at the end of its abdomen, which is thinner, while the female moth has no hair plexus at the end of its abdomen and is enlarged. The eggs are oblong, flat, neatly arranged and difficult to find. When the larvae mature, the body length is about 40 mm, the head is black, the chest and abdomen are yellow-green. The dorsal midline is dark green, with yellow-green and cyan-gray transverse bands on both sides, obvious black tumor-like processes in each segment, and bristles on the tumor process. Pupa spindle-shaped, 8 hip spines, arranged in a row, the tip curled into a hook.

There are 5 generations a year in Nanchong, Sichuan, 3 generations a year in Shanghai, Jiangsu and Zhejiang, and 2 generations a year in North China, all of which overwinter as larvae in leaves. The overwintering larvae in North China were damaged from mid-March to early April, reached its peak in early May, pupated in the affixed leaves in the middle of May, and the pupal period was about 9 days. The adult has weak phototaxis, the female lays eggs on the back of the leaves, and the egg period is about 7 days. The larvae are 6 instar. The larvae in Shanghai area were harmful, the first generation was from early May to early June, the second generation was from early July to early August, and the third generation was from late July to late September. If the control is not timely, the leaves will nibble away at the light, and the plants will turn yellow and wilt. In late September, the larvae net and decorate the leaves to make bags, and the cocoons in the bags overwinter. The natural enemies are concave-eyed wasps, ants, egg-jumping wasps and so on.

Integrated prevention and cure

The main results are as follows: (1) artificial control combined with maintenance and management, the nests of leaf insects are removed in time, and the larvae or pupae are eliminated.

(2) trapping and killing adults with black light.

(3) when the chemical control is serious, spray 5% Nongmont EC or more than 10% Laibao glue suspension 2000 times to control the insect population and reduce the damage. To strengthen the investigation of insect situation, it is best to take medicine in the evening, the effect is better.