[Harmful symptoms]
Nymphs and female adults often suck sap on branches or leaves single-headed or clustered, and excretion of honeydew causes soot disease to occur, and severe occurrence can cause branches to die and the tree to weaken.
[Prevention and control methods]
(1) Do a good job of quarantine of seedlings, scion and rootstock to prevent insects from being brought into the new area. (2) Protect and release natural enemies. (3) When it occurs seriously, it should be sprayed in time to kill. From the winter gardening period to the germination of spring buds, 30% sodium thiorilate aqueous agent 1000-1500 times liquid, 99% mineral oil 200 times liquid, spray 10% diesel emulsion with oil content before germination; young bud stage or flowering stage, young fruit stage, master the wandering nymphs when the wax is not secreted wax spray organophosphate and other agents, such as 22.4% spironoid ethyl ester 4000-6000 times, 25% thiazinone emulsion 1500 times liquid, 99% mineral oil, 0.3% neem emulsion 1000 times liquid, etc.
[Morphological characteristics]
The female adult is covered by a thick ash shell, oval in shape, 4–6 mm long, with a hemispherical dorsal bulge, a higher central bulge, a tortoiseshell-like concave surface, a thick wax layer at the edges and a curved coil consisting of 8 pieces. The back of the live insect wax shell is reddish with milky edges, and the reddish color disappears after death; the live insect body is light brown to purple-red. The male is 1.0–1.4 mm long, reddish to purple-red to dark brown, darker in the dorsal plate of the head and thorax, black eyes, filamentous antennae, 10 segments, wing pairs, translucent, with 2 thick veins, small feet, and slightly thinned ventral ends. The ovoids are oval, 0.2–0.3 mm long, initially pale orange-yellow, purplish-red before hatching. The nymph hatcher is 0.4 mm long, short oval, flattened, pale yellowish brown. The compound eyes are black, the antennae and feet are well developed, grayish-white, and there are 1 pair of long hairs at the end of the abdomen. The second-instar nymph is covered with a white wax shell on its back, with 13 star-like wax horns on the periphery, a longer head, and a shorter tail end. Later wax shell thickened and enlarged, male and female wax shell morphology differentiation, male wax shell oblong oval, surrounded by 13 wax horns like a star, female wax shell oval, star wax shell gradually disappeared, around the formation of 8 circular wax process. The male pupa is a naked pupa, oval in shape, with an average length of about 1.2 mm, purple-brown, darker wing buds, and a sharp sting.
[Life Habits]
Nymphs overwinter, lay eggs begin in mid-to-late April, spawn in May, and appear from late May to mid-June until the beginning of August. Females begin to migrate to new shoots in early July, while males parasitize the petioles and veins of the leaves. From mid-September to mid-October, the spawning period of females is generally 7-10 days, with each female laying up to 1000-2000 eggs, and many up to 4000 eggs. The amount of eggs laid varies depending on the host plant and nutritional conditions. Egg stage 21-30 days, the hatching nymphs first stay under the mother for a few days before crawling out, first on the twigs, and climbed to the leaves for a short feeding, and then wandering to find a fixed position, when fixed for 12-24 hours, the back of the body secreted wax, two columns of white wax spots appeared, and then the wax spots were connected into strips, and white mango-like wax horns appeared around the worm body. The female is infested on the leaves for 1 to 2 months before turning to the branches. Males pupate under the wax shell and pre-pupate, with an average pupal period of 9 days. After 1-2 days of feathering, the male flies out of the wax shell, can cross the tail multiple times, and has a lifespan of 1-3 days. It is feasible for parthenogenesis, and the offspring are all males.