This morning Xiaobian was woken up by a friend's phone call in Xuchang, and the friend was particularly anxious on the phone, saying that there was an American white moth in his nursery. The harm is particularly severe, and the leaves of some trees are eaten in one night, and the harm is very serious.
Xiaobian said that he was very shocked, the American white moth is an exotic species, the harm is very serious, xiaobian is aware, but according to the small editor to understand that the American white moth has not yet occurred in Henan Province, so let the friend take a picture of the pest in the nursery and send it over, which has the following pictures:
The picture shows the feathered adult:
The picture shows the eggs on the tree:
Xiaobian's friend did not send the picture of the larvae of the pest, but when you look at the adult insect, you know that this is one of the ruler moths - silk cotton wood for the ruler moth, then the larvae are self-evident, it must be - silk cotton wood Venus inchworm.
<h1>1. What is Silk Cottonwood Venus Inchworm? </h1>
The silk wool wood Venus inchworm is a species of the Lepidoptera Ullaidae.
Distribution:
North China, Central South China, East China, North China, Northwest China, Northeast China and other places.
Main hazard plants:
Silk cotton, large-leaved boxwood, Fufang vine, Wei spear, zhengmu, Privet, white elm and qilixiang and other garden plants. The insect is one of the main pests on the large-leaved boxwood, and when severe, it will eat the leaves and affect the normal growth of the plant.
Larvae are leaf-eating pests, often outbreaks, the light leaves of the victim plant are eaten into a lack of moments, or because the leaves of the bulbous canopy are eaten, they become clumpy baldness, and the severe whole leaf pieces are eaten, resulting in most of the branches dying, or even the death of the whole plant, which seriously affects the growth of the tree and the landscape effect.
<h1>2. Morphological characteristics:</h1>
imago:
It is about 13 mm long and has a wingspan of 38 mm. The head is dark brown, the abdomen is yellow, the wings are white, and the wing surface has light gray and yellowish brown markings. The forewings have nearly circular spots in the middle chamber and dark yellow, brown, and gray spots at the base of the wings. The hindwings are sparsely grey-
ovum:
The egg is oblong, gray-green, and has a reticulated surface. After adults feather, most of them lay eggs on the back of leaves, branches or weeds.
larvae:
When old, the body is about 33 mm long, the body is black, the dorsal plate of the front thorax is yellow, and there are 5 black spots on it. The abdomen has 4 bluish-white longitudinal stripes, the valve line and ventral line are yellow, wider, and the hip plate is black. Pupa brown.
<h1>3. Occurrence law:</h1>
Generally, 3 to 4 generations occur every year, and the pupae overwinter in the soil. The overwintering adults in early and mid-March of the following year feather and lay eggs on the back of leaves, branches or weeds, in a lumpy manner. The first generation of larvae begins in mid- and late April, the second generation of larvae begins in early and mid-June, the third generation of larvae begins in mid- and late-July, and the fourth generation of larvae begins in mid- and late-September. The larvae can spit silk and sag and metastasize into pests. After the larvae mature, they climb under the trunk or spit silk down to the ground to pupate overwinter.
The following figure shows the occurrence process of silk cotton wood Venus inchworm:
<h1>Integrated management approach:</h1>
1. Light Booby Trap:
Use black light to trap adult insects.
2. Artificial prevention and control:
Combined with tree maintenance and management, it can loosen the soil in winter to kill pupae; using the drooping habit of the spit silk, it can be shocked to collect larvae to kill.
3. Biological control:
The larvae are sprayed with 600 times the biological agent Bt emulsion 600 times liquid at the pest stage, or sprayed with the liquid of 100 times the wettable powder containing 10 billion spores per gram, and the insecticidal effect is more than 85%. It is necessary to pay close attention to the prevention and control of 1 to 2 generations of larvae, and requires uniform and thoughtful spraying. However, when insects and mites are combined, 20% chrysanthemum emulsion can be sprayed with 2000 times liquid control, and insects and mites can be treated at the same time. When the control index is 5 to 7 larvae per 100 compound leaves, it should be treated within 7 days, otherwise, it will cause the flowers or leaves to be eaten.
4. Chemical control:
During the larval occurrence period, spray 90% crystalline enemy insects and leaf insects to clear 1:500 times liquid, and the insecticidal effect can reach more than 95%.
5. Protect and use natural enemies: such as concave-eyed wasps, fine yellow wasps, red-eyed wasps, two-point broad-bellied mantises, white zombies, chicks and stone dragons and other more than 10 kinds of natural enemies. Red-eyed wasps (egg parasitic wasps) can be released in a national locust forest or park, and the parasitic rate is 40% to 77%.
Remember: Because adults lay eggs and plant leaf backs, branches, branches and weeds, it is also necessary to pay attention to the prevention and control of weeds in the process of control.
<h1>Small talk</h1>
The feeding range of the silk wool wood Venus inchworm is almost limited to the large-leaved boxwood and its variants of the genus Venom. Four generations occur every year, with old mature larvae entering the soil to pupate overwinter, and the first generation of larvae is the most harmful.
This period of time is almost the peak of the harm of its first generation of larvae, if you find this pest in your nursery, remember to prevent it in time!