What are the characteristics of Robinia pseudoacacia valley moth? What is the method of prevention and control?

Robinia pseudoacacia valley moth is commonly known as Robinia pseudoacacia. It mainly harms Robinia pseudoacacia. When the larvae eat the trunk cortex, the tissue in the affected part is proliferated and expanded, the bark is warped and cracked, the skin is filled with rotten tissue, and the skin is sewn with insect dung, which can lead to the weakness of the tree and even the death of the whole plant.

Adult, female moth 7 mm 10 mm long, wingspan 17 mm 22 mm, male moth slightly smaller; gray-white or black-brown body, chest and wing base gray-white; forewings gray-white mixed with grayish brown or black-brown scales, wing base with erect dark-brown scale clumps, wing surface 2 horizontal scale clumps oblique, each row of clusters, hind wings and abdomen gray-yellow; female ventral tip, no scale bundles, male ventral end flat, with scale bundles. Egg, round, white at first, then yellow to yellowish brown. Larvae, the last instar body is about 20 mm long, yellowish-white, head reddish brown, the anterior part of the forechest dorsal plate is light brown, and the posterior part is dark brown. Pupa, ca. 10 mm, reddish brown. Cocoon, gray-white, nearly cylindrical, round at the bottom, flat at the top, with a round cocoon cover.

Robinia pseudoacacia valley moth produces two generations a year and overwinters with larvae of different instar in the tunnel under the bark. In the following year, there is active feeding in late March and the peak period of adult Eclosion in the middle of May. The first generation of eggs occurred from early June to mid-July, larvae appeared in mid-June, pupation began in mid-July, Eclosion into adults from late July to early September, and reached the peak of Eclosion in mid-August. In the second generation, the eggs occurred from early August to mid-September, hatched into larvae in mid-August, and the larvae overwintered one after another in late October. Adults lie still during the day, mate and lay eggs at night. Most of the eggs are laid in the wounds of the branches, but also in the seams of the skin, each pile of 430 eggs, covered with yellow egg catkins. The egg period is 613 days. The newly hatched larvae sneak into the subcutaneous feeding cortex, decay into a longitudinal tunnel between the phloem and xylem, make a hole with a gap in the bark, and the hole is covered with silk-covered insect dung. After repeated victimization, the tunnel overlapped, the tissue proliferated and expanded, and the bark warped and peeled off. When the larvae mature, they form cocoons and pupate at the mouth of the tunnel. The pupal stages of the overwintering generation and the first generation were 11-23 days and 11-15 days, respectively.

Prevention and control methods. The tree trunk can be sprayed with 20 times of 50% dichlorvos EC to control larvae; during the occurrence of adults, "741" intubation aerosol, 0.35 kg per mu, can be used to kill adults.