The scientific name Drosicha contrahens Walker belongs to the order Homoptera, Polygonaceae. Alias ​​turtle worms, mulberry mulberry, mulberry bed bug. Distribution of Liaoning, Jilin, Hebei, Henan, Shandong, Zhejiang, Jiangsu, Fujian, Guangdong, Taiwan and other provinces.
Host mulberry, peach, grape, apple, broad bean, poplar and so on.
The nymphs of spring nymphs are densely packed on one-year-old mulberry branches or near the base of winter buds, and penetrate the cortex to absorb sap, causing the leaves to discolor yellow or dry coke. Sometimes the mulberry leaves are brown and dry, affecting the development of spring buds, and the female mulberry also damages the leaves. .
Morphological characteristics Adult females are about 12mm long, oval, no thorns, small and short feet, wrinkled and uplifted on the back, super-colored, slightly yellowish edges, tentacles, mouthparts, and feet are black, white backs Wax powder. Male adults 3-4mm, purple-red, black wings, wavy lines on the wings. Egg length 1mm, width 0.7mm, oval, white when the initial production, after the yellow. The oocysts are 5-8 layers long and tubular with eggs circling between layers. The nymphs are similar to the female adults, and the females become wingless adults three times. The males were molted twice and turned into elongated males. The male dragonfly is 3.6mm long, carries a red back, is surrounded by yellow, and the mouthparts disappear. White, long oval.
Life habits 1 generation, wintering in eggs in oocysts. In February of the following year, the hatching was unearthed as a nymph, and soon after they were unearthed, they climbed onto the main trunk of the plant, intensively in the bark seam or in the leeward position. The high temperatures at noon climbed upwards and caused damage at the top of the branches. During the nymphal period of 105-120 days, waxy substances are gradually secreted. L nymphs 60-70 days, starting in early April, molting, 2nd instar nymphs increased activity, after 18 days, in the second half of April, the second skin, enter the 3rd instar nymph, after half a month, in 5 In the first half of the month, the third skin was removed, forming wingless adults and continuing to harm the saplings. When the male enters the third instar, it turns into a pre-cockroach and secretes a white cotton floc. Several or dozens of twisted knots form a cotton-pig lot, which is pre-puppeted for 9 days. After re-coating, it is officially decanted and the pupal period is 6-9 days. In early May, the males have emerged as winged adults and they begin mating on the following day. The female nymphs became wingless adults after the third skin, averaged after 5 days, and the tails were mostly in the morning. Each time they lasted 15-30 minutes, they continued to feed for more than 20 days after mating, and they laid eggs in mid-May. The spawning period is about 4-5 days and the life span is 30-32 days. Natural enemies include red-edged ladybugs.
Prevention methods (1) Summer plowing, digging out oocysts. (2) The nymph is wiped off with coarse cloth, silk paws, and the like. (3) Continuous spring-cutting for 2-3 years, causing mulberry to die without feed. (4) Strengthen quarantine to prevent its spread. (5) To control the spraying of 50% malathion EC or 50% CASA, 50% phoxim, to the mulberry or trunk when the waxy secretion is low before the germination of young mulberry sprouts or young mulberry in early spring. 10oo times liquid, such as adding 1% neutral detergent effect is significantly improved. In the early spring, when the stalks are dislocated to open 2-3 leaves, they can be sprayed with 1:1 mixture of 90% crystal trichlorfon 1000 times and 40% dimethoate l000 times or 48% chlorpyrifos 1300 times, 10%. Imidacloprid wettable powder 2000 times, 5% Ruijin special suspension agent 1500 times. (6) Protect and use natural enemies such as red beetles.
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