What is the "demon" of the American white moth?
American white moth is an international quarantine pest, its adaptability is strong, the amount of reproduction is large, the number of hosts is large, the transmission route is wide, the harm is extremely great, seriously affecting the growth of flowers, vegetables, weeds, crops, garden trees and other plants, is called "smokeless fire" by forestry workers, that is to say, the harm is serious to no harvest. Therefore, it is not an exaggeration to be called the "demon" of the plant kingdom.
Next, let's first see what the American white moth looks like?
American white moth larvae
The American white moth, also known as the American lamp moth and autumn caterpillar, is an insect of the lepidoptera lamp moth family, a worldwide quarantine pest, and has been listed as the first batch of invasive alien species in China. The American white moth is a completely metamorphosed insect with 4 stages of ontology: eggs, larvae, pupae, and adults.
Eggs: The eggs are spherical in shape, with hundreds of eggs arranged in monolayers on the back of the leaves, covered with the white body hair of the female. The egg is about 0.5 mm in diameter and begins as a glossy pale yellowish-green or pale green, then turns grayish-green to grey-brown. A female moth lays an average of 300-600 eggs at a time, up to 1900 grains, and can breed 3 generations in 1 year, with a huge amount of reproduction.
ovum
Larvae: Larvae have two kinds of black head type and red head type, china found are black head type, and there are 3 kinds of body color variation: ordinary type, the back of the body has a black wide longitudinal band, is the most common type, the number is also the largest; yellow type, insect body yellow, no black wide longitudinal band, only black small hair; black type, the insect body is all black brown.
The older larvae are 28–35 mm long and about 2.7 mm wide. A black band runs through the sides of the dorsal body, and there are irregular gray or black spots. There are 7 to 8 protruding tumors on both sides of the anterior part of the abdomen, and the tumors are covered with white and mixed with long black-brown bristles.
larvae
Pupae: The American white moth pupa is 8–15 mm long and is dark reddish-brown. The head and the back of the anterior and middle thorax are densely covered with irregular fine wrinkles, internodes are inwardly constricted, and the ends are enlarged and centrally sunken.
chrysalis
Adult: The body is pure white and has no other pigmentation. The forewings of non-overwintering adults are overwhelmingly white, with only the males having several black spots on the forewings; the forewings of overwintering adults have many black spots, a few females have 1 to several black spots, and the males have wing spots.
What are the habits of the American white moth?
There are three generations of American white moths a year, a large number of overwintering adults appear from mid-April to early May, a generation of larvae occurs from early May to mid-June, a generation of adults occurs from late June to late July, a three-generation larval stage from early September to late October, and pupate overwintering begins in late September.
The adult insects of the American white moth have phototropism and flavor tendency, and are more sensitive to fishy odors, so they generally occur seriously in places with sparse trees, good lighting conditions, or odorous puddles, toilets and other places that emit foul odors.
After a few hours of hatching, the larvae spit out a mesh of wire, and the net is white, like a curtain, called a mesh curtain. Young larvae feed on the mesophylls in the mesh, and the superficial mesophyll is nibbled on, leaving only the veins and white membranous leaves. After the 5th age of the larvae, the larvae enter the gluttonous period, at this time a large number of cannibalization leaves, so that the leaves are missing and holes, and when severe, the leaves are eaten out, and the tree is eaten as "bald".
Symptoms of American white moth harm
Why is the American white moth so terrible? It is simply summarized as: can eat, can endure, can be raw, can run
First, the number of hosts is large
American white moth is a typical multi-food pest, American white moth is a typical multi-food pest, in China's host plants as many as 49 families, 108 genera and 175 species, mainly harmful to a variety of broad-leaved trees. It prefers to eat all kinds of green trees, fruit trees and some vegetables. Including the common green trees in our community, such as locust, paulownia, poplar, willow, elm and so on.
Second, strong adaptability
The American white moth is extremely adaptable to harsh environments
Cold resistance: can withstand the low temperature of minus 16 ° C;
High temperature resistance: can withstand high temperature of 40 °C;
Hunger tolerance: In the absence of food, the larvae can survive for 10-15 days, coupled with the huge amount of eggs (mentioned earlier), a female moth can produce at least hundreds of thousands of offspring after 1 year.
Third, the amount of food taken is large
The larvae of the American white moth eat a large amount, can eat all the plant leaves, and eat the bark, seriously affecting the growth of trees, and even invading the farmland, endangering crops, resulting in reduced production and harvest, and even extinction. What is even more frightening is that its larvae and adults are very easy to spread over long distances with human activities and vehicles.
In 2013, the American white moth in Yuncheng, Shandong Province, harmed poplar trees
Beijing Botanical General Hospital