[Harmful symptoms]
Adults lay eggs on newly exposed shoots, and after hatching, the larvae burrow into the buds to eat, and the victims of the young shoots swell to form a tumor-like gall, so that the buds cannot continue to grow, and the petioles and unexploked leaves wither and rot.
[Prevention and control methods]
(1) Strengthen the prevention of seedlings, insect-bearing (pupae) soil and scion from entering insect-free areas and new planting areas in epidemic areas. (2) In winter, the garden is combined with shallow ploughing tree trays to destroy its overwintering places and reduce the density of occurrence; during the spring bud period, the orchard is often inspected, and when the young shoots are found to be damaged, they are erased at any time and burned centrally. (3) Pay attention to the protection and utilization of natural enemies such as citrus mosquitoes black bees and long-distance spiny wasps. (4) Before the overwintering adults emerge (before germination) or the larvae enter the soil (that is, the buds wither and the early stage of bud rot), sprinkle medicine on the ground with 3% Miller granules 2.0 to 2.5 kg per acre, sprinkle on the topsoil of the tree disc, and can also spray organophosphorus agents on the ground for control; in the park where citrus sprouts mosquitoes occur, when citrus trees germinate, spray with 5% avermectin emulsion 1500 times, 220% methrin emulsion 2000 times, and 48% chlorpyrifos emulsion 2000 times liquid.
[Morphological characteristics]
Female adults are 1.3 to 1.5 mm long, orange-red, and densely coated with fine hairs; compound eye kidney-shaped, black; antennae 17 segments, with short stalks between each segment, densely covered with fine hairs on the nodes; the wings are about 1.4 mm long and about 0.6 mm wide, with 3 wing veins; 8 segments are visible in the abdomen, and the ninth segment is a slender pseudo-oviduct that can be freely retracted. Male adults are yellowish brown , 1.1 to 1.3 mm long , slightly smaller than females ; antennae are 0.94 mm long , 1.5 times larger than females , and the terminal segment has a long stalk connected to the lower segment. The eggs are oblong in shape, about 0.05 mm long, with a smooth surface, milky white at first birth, and later purple-red. The larvae are milky white, spindle-shaped, 3 instars, the hatching larvae are 0.24 mm long and 1.02 mm when mature, and the terminal larvae have a yellow-brown "Y" bone in the center of the second ventral surface, the end of which forms a pair of positive triangular forks. Pupae have 1 pair of frontal bristles on the top of the head, 1 pair of long snorkels on the anterior thorax and dorsal front edge; black compound eyes, shiny, black feet and wing buds; male pupae are 1.2 mm long, with the hind feet exceeding the length of the body, and the middle foot extends to the end of the abdomen; the female pupae is 1.5 mm long, and the hind feet extend to the front of the fifth abdominal segment.
[Life Habits]
Generations overlap, with old mature larvae overseating and overwintering in shallow soils. Laying eggs on buds that have not opened, the hatching larvae burrow into the young buds as a pest, the affected buds are swollen and gallous, the leaflets are curled, or the young shoots shrink into small galls, or the petioles are enlarged and nodular, and the victim site is pale or white-yellow. Before April, about 10 days after the discovery of the victim, the orange buds dried up and fell off. Before the infested grass dries up, the larvae bounce into the earthen chamber to pupate. From April to early May, due to the increase in temperature, the affected buds are often moldy and rotten. The larvae are mostly active on the soil surface of 1 to 2 cm and pupate. After May , the larvae form cocoons in the topsoil until late December or early January of the following year , when they pupate and feather into adults.