1. Harmful symptoms
Adults and nymphs pierce the fruit with a stinging mouthpiece, suck the grout of the fruit, and the young fruit is killed in the expansion stage, resulting in fruit fall, near-ripe fruit is killed, the wound appears macular, or with light green, hardening, and the fruit is dried and shrunken, granulated, or decayed and fallen off. It can also be harmful to young shoots.
Prevention and control programmes
(1) In the early morning and evening on rainy and sunny days, adult insects can be killed with net pockets. During the spawning period, the orchard is often inspected, and the egg blocks and undiminished first-instar nymphs are removed in time; when the nymphs are dispersed as pests, the plants with fruits can be inspected and the insects can be caught.
(2) Protect and utilize natural enemies, the parasitic bees commonly found in citrus orchards are lychee egg jumping bees, lychee eggs flat-bellied wasps, etc.
(3) During the peak of adult insects and nymphs, spray agents are used for control. The agent is selected from 90% crystalline dimethodium 800 times liquid, 5% acetamidine emulsion 1500-2000 times, 480g/L chlorpyrifos suspension 1000-2000 times and so on.
3. Morphological characteristics
The adult body is 22 mm long, green, long shield-shaped; antennae linear, 5 segments; the sides of the anterior edge of the dorsal plate of the anterior thorax are horn-like protruding and sharp, so it is called horned shoulder bug. The edges of the horned shoulders are black with many coarse black indices; the dorsal plate of the forebreast and the leathery wing part are densely marked; the compound eye is prominent; the small shield is long, large tongue-shaped, and there are many notches; the forewings are green with brown spots at the shoulder corners, and the membranous parts of the wings are grayish brown to dark grayish brown. The eggs are pale emerald green, spherical in shape, and 2.5 mm in diameter. Nymphs are 5 years old, pale yellow to reddish yellow with dark spots in the first to third instars, green in the thorax and yellow in the abdomen with prominent wing buds in the fourth instar, and green in the whole of the fifth instar nymphs.
Fourth, life habits
In the south, it occurs for one generation per year, with adult insects overwintering in dense citrus branches and shade of grass. In April of the following year, it began to sting activity, feeding, and mating, and the spawning period was from May to October, and the most eggs were laid in July, the eggs were laid on the leaf surface, and a few were laid on the fruit surface, each egg block was 14 grains, often arranged in a "B" shape or irregular arrangement. From July to August, when nymphs are in full bloom, in order to harm the young fruits that are expanding, at least more than ten nymphs on a tree scatter and suck juice, resulting in serious shedding of young fruits. Newly hatched nymphs are clustered around the egg shell, do not feed as a pest, the second age begins to eat scatteredly, often 3-5 head cluster, four or five years old scattered active feeding. Adults often inhabit the fruits and leaves and flee in case of alarm. Most of the molts turn into adults in November, and the overwintering begins in early December.
5. Hazards
Leaves lose green, stiff fruit, and reduce yield