Morphological characteristics: adult male moths gray-brown, female moth gray; forewings narrow, long dark brown dots, of which the front edge color is slightly pale, the trailing edge from the fin base to the corner has a yellow-white wavy band pattern, the front edge of the pattern was three The degree of twists and turns, when the two wings cover at the back of the body, the shape of the ridge, wavy lines into a series of three oblique square yellow and white spots; forehead long hair, tilted like a chicken tail. The egg is oval in shape, pale yellow, slightly flat, and has a smooth surface. The larva body is spindle-shaped, with two pointed ends and a distinct body segment. The hip foot extends backwards beyond the end of the abdomen and has a greenish or grayish white body and a brown head. At the beginning of the beak, it was light green, and then it turned gray-brown. It was surrounded by sparsely thin, thin and thinly wrapped pods. The pods were mostly spindle-shaped and the pods were visible from outside the pods.
Life habits and damage characteristics: adult moths are nocturnal and have phototaxis. In the northern regions, Plutella xylostella overwinters mainly in winter, while in the south, there are no overwintering and over-summer phenomena. Adults can be bred for one feather, and can be mated multiple times in a lifetime. After mating 1 to 2 days, eggs can be laid and the egg period is 3 to 11 days. Newly hatched larvae often bite into the epidermis of the leaves and drill the first half of the body into the upper and lower epidermis to feed on the leaf; the first instar larvae damage the leaves, forming a transparent spot, called "open skylight"; 3 to 4 instar larvae The leaves form holes or nicks, and the leaves are eaten into a net when serious. In the seedling stage, they are concentrated on the harmful leaves. As soon as the larvae start to move, they twist their bodies and go backwards.
Prevention methods: 1 Agricultural control: Rational distribution, try to avoid the annual continuous cropping of cruciferous vegetables in small areas, and reasonably mix and match Chinese cabbage early, middle and late-maturing varieties. 2 biological control: the application of bacterial pesticides, such as using 10% live spores containing acaricidal bacteria, Bacillus 140, Bt powder and other Bacillus thuringiensis preparations 500 to 1,000 dilution and 0.1% detergent spray. 3Chemical control: 50% Bataan wettable powder 1000-1500 dilution, 50% phoxim EC 2000 dilution, 10% Pesticide EC 2000-2500 dilution, or 50% Plutella x enemy oil 700-1000 dilutions were sprayed and killed.
Life habits and damage characteristics: adult moths are nocturnal and have phototaxis. In the northern regions, Plutella xylostella overwinters mainly in winter, while in the south, there are no overwintering and over-summer phenomena. Adults can be bred for one feather, and can be mated multiple times in a lifetime. After mating 1 to 2 days, eggs can be laid and the egg period is 3 to 11 days. Newly hatched larvae often bite into the epidermis of the leaves and drill the first half of the body into the upper and lower epidermis to feed on the leaf; the first instar larvae damage the leaves, forming a transparent spot, called "open skylight"; 3 to 4 instar larvae The leaves form holes or nicks, and the leaves are eaten into a net when serious. In the seedling stage, they are concentrated on the harmful leaves. As soon as the larvae start to move, they twist their bodies and go backwards.
Prevention methods: 1 Agricultural control: Rational distribution, try to avoid the annual continuous cropping of cruciferous vegetables in small areas, and reasonably mix and match Chinese cabbage early, middle and late-maturing varieties. 2 biological control: the application of bacterial pesticides, such as using 10% live spores containing acaricidal bacteria, Bacillus 140, Bt powder and other Bacillus thuringiensis preparations 500 to 1,000 dilution and 0.1% detergent spray. 3Chemical control: 50% Bataan wettable powder 1000-1500 dilution, 50% phoxim EC 2000 dilution, 10% Pesticide EC 2000-2500 dilution, or 50% Plutella x enemy oil 700-1000 dilutions were sprayed and killed.