The diamondback moth, belonging to the order of the genus Hymenoptera, the genus Coleoptera, is also called the diamondback moth, commonly known as the square moth, the two-headed tip, the small green worm, the twisted worm, and the hanged ghost. It has occurred all over the country, especially in the south, and it is an important pest of cruciferous vegetables.
The diamondback moth is mainly caused by larvae, and the semi-dive leaves of the newly hatched larvae are harmed, that is, the mesophyll is drilled between the upper and lower epidermis of the leaves of the body, and one epidermis is left, or a small tunnel is formed in the petiole and veins. However, the amount of food is small and it is not easy to be found. When the larva grows up, the leaves are eaten into holes or nicks. In severe cases, the leaves are eaten into a net shape. The larvae also have a habit of concentrating on the heart of the cabbage, affecting the growth and filling of the vegetables. On the seedlings, the larvae can feed on the tender stems, eat the tender pods, and bite the tender pods and kernels, affecting the seed.
First, shape recognition
1. Adult Plutella xylostella is a gray-brown moth with a body length of 6-7 mm and a wingspan of 12-15 mm. The wings are long and light, the front half of the front wing is light brown, with brown dots scattered. The back half has a yellow-white three-degree meandering ripple from the wing base to the outer edge, and three consecutive oblique squares when the two wings are closed. The front wing is long and wings like a chicken tail. The antennae are filiform, brown, and have white lines.
2. Eggs Oval, flat, yellowish green, smooth surface with sparkle.
3. The larvae are spindle-shaped, yellow-green, with a body length of 10-12 mm. They have fine hairs on the body, and the body segments are obvious. The two ends are thin and pointed. The chest plate has brown spots on the hard skin and is arranged in two "U" shapes. The fourth to fifth quarter of the abdomen is inflated, and the buttocks are extended backwards.
4. 蛹 5-8 mm long, initially yellow-green, later grayish brown, spindle-shaped, grayish white, transparent and thin like a net.
Second, prevention and treatment technology
(1) Reasonably arrange the mouthwash Try to avoid the annual continuous cropping of cruciferous vegetables in a small area, and stop the transition host in summer.
(2) Clean the countryside
2. Physical control In the adult period, black light can be used to trap adult insects, and a black light is ignited every 6666.7m2, which has a good effect.
3. Sexual attractant moth The so-called sexual attractant is the female moth that is feathered on the day, cut off the abdomen end, and is roughly extracted with diclofenac or alcohol, benzene and other solvents, and the extract is used as a sexual attractant.
4. Biological control Bacillus thuringiensis preparations (bacterial insecticides), such as B.t. emulsion produced by Hubei Academy of Agricultural Sciences, 500-1000 times liquid (about 100 million spores/ml) can be sprayed to kill a large number of P. xylostella larvae.
5. Physiological control can use insects to synthesize inhibitors of chitin, such as 5% inhibition of emulsifiable concentrate 2000-3000 times solution, or 5% of agricultural dream emulsifiable concentrate 2000-3000 times solution, or 20% of domestic production. The jumone urea 1 suspension 500-1000 times liquid, after spraying, the larvae of the diamondback moth can not be removed due to the old skin, and the new skin can not grow out and die.
6. Chemical control 50 phoxim emulsifiable concentrate 1500 times solution, or 10% Uranus emulsifiable concentrate 8000 times solution, or 2.5% kungfu emulsifiable concentrate 3000 times solution, or 24% Wanling water 1000 times solution.