Control of White scale in Tea

The tea white scale belongs to the family Coccidae of Homoptera. It is distributed in most tea-producing provinces in China, and it is an important tea pest in East and Southwest China. In addition to harming tea, it also harms citrus, pear, apple and other plants. It is harmful for nymphs and female adults to prick and suck juice on the branches of tea trees. The injured tea tree sprouted sparsely, the tree was weak, aged at the end, fell leaves in large numbers, and even withered. The shell of the female worm is gray-white, about 1.5 mm long, narrow and slightly eggplant-shaped, with a slightly wider end and a brown shell spot at the front end. There is also a layer of dark brown shield shell under the female shell, and the dark brown shield shell is common in the field in the late growing period.

The female adult of tea is pear-shaped and yellowish. The male adult is a thin, winged pair with a lilac body and a tail organ at the end of the abdomen. The egg is oval, lavender, laid under the shell. The newly hatched nymph is oval, lavender, with feet, antennae and 2 tail hairs at the end of the abdomen, which can crawl. After fixation, the wax secretes on the back of the body to form a shell. The female nymph is fixed on the branch, and the male nymph likes to be fixed on the serrated edge of the tea leaf, and the shell is slender and gray. Male pupa long oval, lavender.

The occurrence regularity occurs in the tea area of the Yangtze River valley for three generations a year, overwintering with old mature nymphs on the branches of tea trees. It emerged in late March and began to lay eggs in the middle and late April of the following year. The hatching period of the first to third generation nymphs is from mid to late May, from late July to early August, and from mid-September to early October respectively. The first and second generation nymphs hatched neatly.

Prevention and control methods (1) seedling quarantine. The seedlings parasitized by scale insects should be disinfected. (2) strengthen the management of tea garden, clear and bright feet. Promote the ventilation and light transmission of the tea garden, cut off the serious tea branches in time; (3) protect the natural enemies. The cleared insect branches should be concentrated and stacked for a period of time, so that the parasitic bees can feather and fly back to the tea garden. Tea gardens with high density of ladybugs can be transplanted artificially, and drugs should be avoided as far as possible during the active period of ladybugs. (4) Pesticide control. Master spraying when nymphs are in full bloom. 25% imidophos, 25% quinathion, 50% malathion, 25% parathion 800 × 1000 times solution can be used. Baume 0.5 degree stone sulfur mixture, 10-15-fold turpentine mixture, 25-fold anthracene oil or engine oil emulsion can also be selected.