[Harmful symptoms]
The use of nymphs and adults to suck up branches, petioles and pulp juices has a great impact on tree potential, yield and quality.
[Prevention and control methods]
(1) Physical control: (1) In the early morning and evening on rainy and sunny days, adult insects can be killed with net pockets. (2) During the spawning period, the orchard is often checked, and the egg mass and the undiminated first-instar nymph are removed in time. (3) When the nymphs are dispersed, the plants with fruits can be inspected and the insects can be caught. (2) Biological control: protection and utilization of natural enemies, the parasitic bees commonly found in orchards are lychee egg jumping wasps, lychee eggs flat-bellied wasps, etc. (3) Chemical control: Adults and nymphs are in full bloom, spraying agents for control. The agent is selected from 90% crystalline diphthalmid 800 times liquid, 5% high-efficiency cypermethrin acetamidine microemulsion 1000-1500 times liquid or 5% acetamidine emulsion 1500-2000 times.
[Morphological characteristics]
Adults are 18–22 mm long and 8–11 mm wide; slightly broader , dorsal brownish brown , with a yellowish-white or yellow longitudinal ridge from the tip of the head to the middle of the small shield ; irregular fine yellow-white raised markings on the dorsal plate , small shield , and leathery part of the forewing ; sparse yellow-white spots in the middle of the posterior end , forming a large nearly circular tan-brown spot ; small yellow spots between the lateral junctions of the abdomen; black or tan of the forewings ; slightly narrower head , anterior tip , yellow-white ridges on both sides of the head ; compound eyes black ; antennae 5 segments , black , black , Filamentous, 1/3 of the base of the fifth segment, yellowish white or yellow; beak 4 segment, pale yellow, terminal segment black, dark brown beak slit; brownish black at the base of the foot, blackish brown at the end of the tarsal segment, with 1 pair of claws; and an opening of volatile odorous glands next to the base segment of the posterior foot. The eggs are nearly round, pale green at first birth, grayish-brown before hatching, with a capped cap and a toothed lid. The hatching nymphs surround the egg shell and are later scattered for feeding, with different colors and shapes of each age, starting at the beginning of the third instar period, and the pre-sharpened round pear-shaped; the elderly nymphs are about 19 mm long, resembling adults.
[Life Habits]
Due to geographical differences, the annual generational number varies. In the northeast, there are 1 generation a year, Jiangxi and Guangxi 3 generations a year, and Guangzhou 4 generations a year. Adults overwinter in grass or tree holes, bark cracks, dead branches and leaves, wall crevices, and eaves. From April to May of the following year, citrus begins to be active, spawns and is harmful to flowers and young fruits, laying eggs on the leaves, lumpy, generally 12 grains, but also 9-11 grains, arranged in 2 rows or irregularly. The egg stage is about 10 days, with hatching nymphs visible in mid-to-late May, the first peak in June, the feathering of adults in July and August until late autumn, and the third peak in early to mid-October, followed by overwintering. Both adults and nymphs use a tapered mouthpart to suck up plant sap. Adults are highly flying, prefer to move in the upper parts of the tree, have pseudo-death, and secrete odorous liquid when disturbed.