Identification and control of tea whitefly whitefly

Black whitefly, also known as orange whitefly, belongs to the family Homoptera, which can damage tea, citrus, grapefruit, Camellia oleifera and other plants. The larvae settled on the back of the leaves to suck juice and excreted "honeydew", which led to the occurrence of bituminous disease, hindered photosynthesis, decreased tree potential, sparse buds and even dried up branches and leaves. The adult worm is 1.35 mm long. Except for the orange belly, it has purple-brown body wings, seven white spots around the forewings, light brown rear wings, no spots, thin white wax powder on the body surface and red eyes. The eggs are banana-shaped, 0.21 mi 0.26 mm long, milky white to yellowish brown, attached to the back of the leaves. The larva is black, a total of 3 instar, the first instar is long oval, about 0.25 mm long, flat and smooth, with feet, and there are two slightly curved white wax lines on the back. The second instar larva is about 0.5 mm long, slightly raised on the back, pitch black, the white wax ring around the edge is obvious, there are 10 pairs of thorns on the back, and the foot has disappeared. The third instar larvae are about 0.7 mm long with 14 pairs of spines on the back. The pupa is oval, 1.0 mm long, with 19 pairs of black thorns on both sides of the dorsal spine and 10 pairs (male) or 11 pairs (female) of black thorns on the periphery.

To prevent and control this kind of insect, we should strengthen the management of the tea garden, prune and remove the foot branches to depress the insect population, and second, we should pay attention to protect the natural enemies, and the important link is not to administer medicine blindly. To protect parasitic wasps and ladybugs, whitefly black wasps can be released conditionally. That is, when it is found that there are whitefly black wasps parasitic in the field, do not use medicine, after the parasitism rate is increased, pick the leaves with eggs and put them in other tea gardens. When the insect situation is serious or the insect population is rising, three principles should be adhered to when chemical control is needed: first, to apply the pesticide during the full hatching period of the larvae; second, to ensure the quality of spraying, it is necessary to focus on the lower leaf back of the tea bushes; and third, to choose a good medicine. the medicament can be used with Uranus, Aktai, lice aphid, superior, etc., if it can be mastered well, it can be used in the first generation larva incubation peak, and the medicine can be used only once a year, it can be basically solved.