Citrus acacia (Aleu-rocanthus spiniferus Quaintance) is classified as Homoptera and Pteromidae. In addition to harming citrus, it can also harm dozens of plants. SICHUAN UNIWELL BIOTECHNOLOGY CO.,LTD. , https://www.uniwellbio.com
Hazardous characteristics? Citrus nigra powder is harmful to the fixed suction juice on the back of the nymph gathering leaf, and it can secrete honeydew to induce soot, resulting in dark foliage and weak tree vigor.
Morphology: Black locust whitefly adults are finer than citrus hibiscus. Female adults are 1 to 1.7 mm in length and 2.5 to 3.5 mm in wingspan. They are orange and covered with a thin waxy white powder. The front wings are purple-brown with 7 white markings, and the hind wings are purple-brown with no markings. Nymphs are 3 years old, oblate, black, body covered with black bristles, a circle of white waxy material secreted around the body, the camp fixed parasitic. Pelicans resemble nymphs, oval in shape, black in lacquer, shiny, jagged edges, prominent bulging of the back, and a wide white wax ring around the perimeter.
Habits? Citrus nigrum whitefly occurs in Sichuan in 4 to 5 generations, with 2-3 years old nymphs overwintering in the back, from early March to early April, phlegm, and in mid-to late March, eclosion became adult. Adult hi hi dark environment, more activities in the new shoots within the crown, eggs produced in the back of the leaves, scattered or densely rounded, constant grain to dozens of grains together. Newly hatched nymphs crawling not far, mostly in the camp near the egg shell fixed sucking life, after peeling the husk left on the body back. The last instar nymph hull hardened into a pupa, namely oyster shell. Occurrence of insect population in each generation is closely related to temperature and humidity. Suitable temperature (below 30°C) and high humidity (relative humidity above 90%) are favorable for adult emergence and hatching of eggs. On the contrary, excessive temperature (average temperature above 30°C). And low humidity (relative humidity less than 80%) is unfavorable, so it is usually more dense and dark in the environment. Natural enemies have more than 20 kinds of parasitic bees, parasites, ladybugs, and grasshoppers, such as whitefly, bees and grasshoppers. Natural conditions have better control effects on black locust whiteflies and should be protected and utilized.
Prevention methods?:
1. Agricultural control: (1) Grasp the pruning of the Qingyuan Garden, improve the ventilation and light transmission of the citrus orchard, and create an environment conducive to plant growth that is not conducive to the occurrence of the black sting bug. 2 Reasonable fertilization, diligent application of thin application, and avoidance of partial application of nitrogenous fertilizer lead to plant growth and prolonged development of beneficial insects. 3 During the period from May to November when natural enemies such as parasitic bees prospered, irrigation with citrus orchards and irrigation of the canopy with a high-pressure water column could reduce the “dew dew†secretion of whiteflies and increase the parasitic rate of parasitic parasites and reduce the incidence of soot. The effect.
2. Biological control: It is mainly to protect and utilize natural enemies. 1 When the parasitism rate of natural enemies such as whitefly is 50%, it is not appropriate to use pesticides to avoid massive killing of natural enemies, and it should be selected to have less impact on natural enemies when they are not used. Spraying during the flood season. 2 Severe citrus plants occur in the black locust pollinator, from May to June, the leaves of the whitefly plucked from the white pods of the whiteflies, yellow plucked bees, and yellow shields are collected (7-8 heads/leaf) ) Hanging in the park, no poisonous pesticides will be applied within one year after the release. 3 The biological control park should not be used repeatedly for pesticides such as deltamethrin and cypermethrin that have a great impact on natural enemies.
3. Chemical control: When the whiteflies are seriously endangered and the natural enemies are less able to keep up with the development of pests, 20% to 20% of the WP can be used in the 1-2 years instar nymphs, or 95% Dai Ling EC 200 times, or 90% dipterex crystal 500 to 800 times, or 80% dichlorvos 1000 times, 50% malathion EC 1000 times, or 40% dimethoate Emulsion 1000 times spraying.