Occurrence regularity and control of jujube inchworm

Jujube inchworm, also known as Jujube Buqu, Dingmen eating, Toxoplasma gondii, Lepidoptera, Lepidoptera, is one of the main pests in jujube leaves.

I. occurrence regularity

The larvae harm the tender buds, leaves and flower buds of jujube. One generation occurs every year. The pupa overwinters in the soil 10-15 cm deep around the tree crown. In the first ten days of the next year, the pupae are feathered into adults. After mating, the female adults do not have wings and have to climb onto the trunk to lay eggs. After about 22 days of egg period, the larvae hatch from late March to early April. The food intake of the 1st and 3rd instar larvae was small, which mainly damaged the tender leaves, while the food intake of the 4th and 5th instar larvae increased greatly and often ate up the leaves. After the 5th instar development, the larvae pupated through summer and winter from late April to mid-May. The larvae have strong overfeeding and endanger all the green tissues such as buds, leaves, flower buds, jujube hanging and new shoots of jujube seeds. When it is serious, it can eat all the jujube leaves or buds, resulting in a serious reduction in yield or no harvest. The length of egg period is closely related to the temperature. The higher the average temperature is, the shorter the egg period is. The damage of larvae increases with the increase of instar, and the larvae have pseudo-death and chemotaxis.

II. Prevention and control measures

1. Capture larvae

In spring, within the diameter of 1 meter around the trunk, the soil layer is 15 cm, and the overwintering pupae are dug out and destroyed. Pick out the pupa at any time when planing the tree plate in early winter or early spring. In addition, the characteristics of false death and landing of the larvae after being frightened can be used to shake the trees and shake down the larvae in the larval damage period and kill them on the spot.

two。 Collect eggs

From late February to early March, wrap a plastic film or paper skirt around the tree trunk to prevent female moths from mating and laying eggs, and catch moths from trees every morning or evening. Due to the tangled skirt of the trunk, the female moth can not get on the tree, so it is mostly concentrated in the cracks in the bark under the skirt to lay eggs. Therefore, you can regularly inspect the thick bark, scrape off the eggs, or tie two circles of grass rope under the skirt to attract the female moth to lay eggs, change the grass rope every 10 days or so, and burn it.

3. Drug prevention and treatment

According to the characteristics and harm law of jujube inchworm, it can be used twice. For the first time, when the jujube bud grew to about 3 cm, 50% dichlorvos or 75% zinc parathion was sprayed 800 / 1000 times, or 50% parathion 1000 / 1500 times. For the second time, when the jujube bud grows to 5-8 cm long, 20% Chrysanthemum Horse EC can be sprayed 4000 times, or 35% insecticidal phosphorus EC 1000 times, and so on.

4. Biological control

Protect natural enemies and reduce population density.