1. Harmful symptoms
Female adults and nymphs are fixed on the leaves, fruits and young shoots to suck sap, and the macula is formed in the victim area, resulting in leaf deformity, curling, dry branches and leaves, and the fruit is yellow-green, with poor appearance and fruity taste; it seriously affects the tree posture, yield and fruit quality, and can also induce bituminous coal disease.
Prevention and control programmes
(1) Agricultural control: cultivate tree potential and improve the insect resistance of the tree itself. Before April, timely pruning of insect branches, shaded branches and dry dead branches to improve the ventilation and light transmission conditions of citrus orchards. Found that the fruit surface and branches have a jagitic tip hazard in time to remove. (2) Biological control: protect natural enemies, such as predatory predators such as Japanese square head beetle, red spot lip ladybird and Hubei red spot lip ladybird, etc., important parasitic natural enemies are arrow-tip aphid wasps, flower horn aphid wasps, etc.
(3) Chemical control. Spray 99% mineral oil emulsion 200 times, 51.5% per chlorine chlorpyrifos emulsion 1500 times, 48% chlorpyrifos emulsion 2000 times alone or in combination; if the ophins can be controlled, 48% chlorpyrifos emulsion, 25% thiazide ketrazone emulsion, 51.5% per chlorine chlorpyrifos emulsion, etc. can be used. Severe episodes occur every 15-20 days, 2-3 times in a row.
3. Morphological characteristics
(1) Adult worms. Female adults have yellowish brown or brown shells with grayish-white margins, a pointed anterior end, a broad posterior end, and a distinct longitudinal back in the center, resembling an arrow-like shape. The male body is elongated, pinkish white, and cotton-wooly.
(2) Eggs. Oval, 0.2mm long, orange-yellow.
(3) Nymphs. The 1st instar nymph is shoe-shaped, orange-yellow, with well-developed antennae and feet, and the end of the abdomen has l pairs of long hairs; the 2nd nymph is flattened and oval, pale yellow, and the antennae and feet are disappeared.
(4) Pupae. It is 1.4 mm long, orange-yellow with prominent sexual spines.
Fourth, life habits
The hatching nymphs are active, and after 1-2 hours, they settle on the host to suck, and the next day the body begins to secrete cotton-like wax. The insect body continues to grow under the molting shell and molts into a female adult; the male nymph secretes a woolly waxy shell after 1 year of age, often grouping into pieces.
5. Hazards
The leaves are yellowed, affecting the smoothness of the fruit surface and reducing the quality