Control of Stenocarpus euonymus

Euonymus tomentosa is a tree species with more seedlings for greening. In recent years, it has been found that Euonymus tomentosa has gradually developed from sporadic death to piece death in Nantong area. The dead tree was broken from the root neck and a moth-eaten tunnel was found. It is observed that this is the harm of narrow gibberellin.

Euonymus macrophylla belongs to Coleoptera (Coleoptera). The larva eats the stem of Huangyang with big leaves, causing the plant to grow weak until it dies.

1. Morphological characteristics

Adults: 5-7 mm long, compact structure, head and chest dark brown, sheath wings bronzed, with a wide oblique black spot in the middle of the back. The top of the head of the male and the female is different, the top of the male is blue and the female is brown. Larva: it is known as "flat head drill nail". The mature larvae are 10-13 mm long, flat and beaded, milky white. The forechest is broad and flat. There is no foot in the chest, and the middle chest valve is larger than the abdominal valve, showing a crescent shape. The cephalothoracic dorsal plate has a brown stripe and a pair of brown tail clips at the end of its ventral segment. Pupa: fusiform, the first pupa is milky white, black before Eclosion, 6-8 mm long. Eggs: White, globose, 1 mm in diameter.

II. Life habits and life history

One generation occurs every year, overwintering as larvae. The overwintering larvae were active from late February to April in the following year, pupated in May and emerged into adults in June. Adults are rarely seen on Populus tomentosa. The adults rest on the back of the branches and leaves of other plants around them sooner or later, with pseudo-death and slightly phototaxis. The peak period of adult activity is at the end of June, and the peak time of adult activity is at noon every day, feeding on tender leaves and mating. Adult Eclosion begins with female and then male. The larvae appeared in July, and at the beginning of August, a few larvae were eaten into the burrow of the xylem, and the body overwintered in a folded posture. The eggs lay around late June, lay eggs at the cracks in the stem bark, and hatch in late June and early July. After hatching, the larvae eat upward spirally under the skin of the stem, and the feces are brown without excretion. In late July, there were 3-5 larvae in the diameter culm under the injured skin, and the plants showed light leaf color and wilting state, and withered in severe cases. In the first and middle May of the second year, the larvae began to pupate, turned into the first pupa after about 8 days, and emerged as adults after 13 days.

III. Prevention and treatment

⑴ management should be strengthened to remove plants that are dead or eaten by larvae in winter and become severely wilted, blistered, deeply buried or burned by fire. ⑵) according to the characteristics of the diurnal activity of adults, seize the opportunity in mid-late June to spray dimethoate or enemy insecticides on the trees and plants around the plant to kill the adults. ⑶ digs larvae. When the larvae first enter the xylem, the bark can be cut off with a knife to dig out the small larvae. ⑷ injected insecticide into the insect eye and sealed it with thin mud. ⑸ applied absorbent insecticides to the roots of unwithered and wilting plants.