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Occurrence and Control of Black Locust
Also known as orange thorn mealybug. Hexoptera is a whitefly family. All tea producing provinces in the country are distributed. In addition to harming tea, it also harms citrus, camellia, pear, persimmon, grape and other plants. The nymphal parasitic parasite sucks sap from tea leaves and induces severe bituminous coal disease. Insect pests and insects, loss of nutrients, photosynthesis blocked, weak tree vigor, sparse shoots, so that branches and leaves depleted, even when severe stems cause dead trees. 1. Morphological characteristics: The adult body is about 1.2 mm in length, orange yellow and compound eye red. The front wings are purple-brown with 7 white spots on the periphery. The rear wings are lavender, without markings. The body surface is covered with white wax powder. The egg is banana-shaped and has a round blunt end, and has a short stem fixed to the back of the leaf. It is milky white at the time of its initial production, and gradually turns into a brownish-brown and purple-brown color. The larvae hatched in an elliptical shape, light yellow, and had enough feet to crawl. They quickly turned black after fixation, and two white wax lines appeared on the reverse side as "8". As the body grows, black stings appear on the back and white wax rings surround it. The oyster shell is shiny black and oval and is about 1 mm long. A total of 29-30 pairs of black thorns are on the back and periphery, and 2 nymph shells are often attached to the back. 2. Occurrence pattern: Lishui tea area takes 4 generations a year. It is overwintering with the old nymph or cricket on the back of the victim's leaf. In mid-April of the following year, the overwintering adults emerged. The fourth generation larvae occur in late April to early June, from mid-June to late July, from early August to mid-September, from late September to March of the following year. When the adult eclosion occurs, the back of the oyster shell presents a "⊥" shape hole. Eggs are prolific in the back of leaves or young leaves. After the nymph is immobilized and secreted, it is fed in its original place for life, and the nymphs mature in their original place. 3. Control methods: (1) Strengthen the management of tea gardens: timely tea-picking, sparse branches and clearing of gardens, cultivating weeds, and promoting tea plantation ventilation and light transmission. (2) Biological control: The parasitism rate of long-plankton broad-spot bee and black-white bee is very high. In the old-age nymphs and beryllium of black-spotting aphids, drug use must be controlled to protect natural enemies; Longer-term effect. (3) Chemical control: At the end of each generation of nymphs, spray 10% imidacloprid wettable powder 1500-2000 times or 2.5% Uranus EC 1500-2000 times, and select 80% of dichlorvos EC at 1000 times or 35 times during adult emergence period. % chlorpyrifos EC 100-1200 solution.