One worm of the day: Oyster oysters

[Harmful symptoms]

It is mainly harmful to branches and leaves, but also to harmful fruits. In the case of serious victimization, the branches wither and the leaves fall early.

[Prevention and control methods]

(1) Agricultural measures: combined with the whole branch, cut off the insect branches and leaves and burn them. When there are insects on the branches and leaves, the light ones can be removed with a brush. (2) Biological control: protection and utilization of natural enemies of insects, such as orange long tamarind wasps, red-spotted lip ladybirds, etc. (3) Chemical control: During the incubation period of nymphs, spray 48% chlorpyrifos emulsion 1000 times liquid, 25% thiazideone emulsion 1500 times liquid, 99% mineral oil, etc. Later, the shell is thickened, and should be used instead.

[Morphological characteristics]

The female adult shell is particularly slender and narrow, 2.5–3.25 mm long, slightly wider at the posterior end, almost parallel or slightly curved on both sides, raised, with narrow flat edges. The shell point protrudes from the front and is pale yellow. The abdominal shell is off-white with larger cracks, and the worm body is obviously visible. The female worm body is narrow and long, 1.5-2 mm long, segmented, the anterior part of the middle thorax occupies half of the total length of the body, the posterior end is slightly wider, yellowish brown, and the hip plate is yellow or reddish brown. The male has a slightly female-like shell , slightly smaller , about 1.5 mm long , pale yellowish brown , white edges , and yellow shell spots. The male adult worm has a narrow and long body length of 0.65 mm and a wing length of about 0.7 mm. The chest and abdomen are equally thick and thin, and the lilac is purple. The eggs are white at first, then lilac, oval in shape, 0.25 mm long, and neatly arranged in two rows within the shell. The primary nymph is oval in length 0.25–0.36 mm, lilac; the second instar nymph is oblong in shape with a body length of 0.37–0.55 mm and is lilac.

[Life Habits]

There are 2-3 generations a year, and the generations in the field overlap. Fertilized female adults overwinter on the branches and leaves, laying eggs in March of the following spring, the first generation of nymphs hatching in May, the first generation of adults occurring in July, the incubation period of the second generation of nymphs in August, and the second generation of adults in October. It is mostly parasitic on the branches and leaves, and is also harmful to the fruit. In the shade of the branches and leaves, it is relatively concentrated, which causes serious soot disease.