1. Harmful symptoms
Adults and nymphs suck sap from the host's branches, leaves and fruit stalks to hinder the growth of the affected plants, and in severe cases, the branches and leaves are covered with a layer of white cotton flocculent wax, resulting in soot disease. Dense orchards or plants with poor ventilation and light transmission are prone to damage.
Prevention and control programmes
(1) Agricultural control: through pruning, the citrus orchard is ventilated and transparent, destroying its growth and reproduction sites; timely pruning of egg branches and burning them in a concentrated manner; nymphs are swept away with brooms during the blooming period of nymphs, and chickens and ducks are released to peck.
(2) Physical control: the adult stage can be booby-trapped with yellow plates.
(3) Biological control: it can be sprayed with a white stiff dilution containing 8 million spores per milliliter.
(4) Chemical control: spraying insecticide should be mastered in the nymph bloom period, and combined with ground spraying. Optional 15% indicosyl emulsion 2500-3500 times liquid, 480g/L chlorpyrifos suspension 1000-2000 times, 22% thiamethoxazine. High efficiency cypermethrin 4500 times, 10% cypermethrin emulsion 3500 times, 10% bifenthrin emulsion 3500 times liquid, 20% cypermethrin emulsion 3000 times liquid, etc.
3. Morphological characteristics
The adult is 68 mm long, the dorsal plate of the middle thorax is well developed, there are 4 russet longitudinal stripes on the forewing, the forewings are pinkish green, the apical angle is blunt, the hip angle is right angled, the wing veins are reddish brown, and the ventral surface of the left and right wings is erect and flat when resting.
The eggs are milky white, nearly conical, about 1.3 mm long, with a fin-like protrusion in the middle to the end of one side. The nymph is white or pale green, covered with white waxy flocculents on the back and sides, and has a bunch of white waxy hairs at the end of the abdomen.
Fourth, life habits
Adults overwinter in dense foliage and begin to move, mate and spawn the following spring when temperatures warm. The eggs are laid under the cortex of the young shoots or petioles, each follicle is independent, jagged and upturned, arranged at a certain distance into 1 or 2 columns, each column has more than 10-20 fossa, and has a white woolly waxy cover. The hatching nymphs are infested on the branches, and as the insects age, they move to larger branches and cluster in one place, secrete a large amount of white cotton flocculent to cover the insect body and the damaged branches, and feather the adult insects here. Adults are mostly white-winged, fewer green-winged, and occasionally pale yellow-green-winged. Once disturbed, the nymph bounces away or lands on the ground, while the adult bounces and escapes and lands on a nearby branch.
5. Hazards
The leaves lose green, affecting photosynthesis and weakening the tree