Identification and Control Methods of the Russian Olive Psyllid

Scientific name Trioza magnisetosa Log. Homoptera, Psyllidae.

Hosts: Russian olive (Elaeagnus angustifolia), jujube.

Damage characteristics: adults and nymphs pierce and suck the sap of young buds, tender twigs and leaves; infested young buds often die, infested leaves mostly curl toward the underside, and in severe cases the twigs and shoot tips die, weakening the tree's vigor, with heavy flower and fruit drop.

Morphological characteristics: adult body length 2.5-3.4 mm, dark green to yellowish brown. Compound eyes large, protruding, reddish brown. Antennae filiform, 10 segments, the terminal 2 segments black, with 2 hairs at the tip. Pronotum bow-shaped, anterior and posterior margins dark brown, with 2 brown longitudinal bands in the middle. Mesoscutellum with 5 brown longitudinal stripes. Wings colorless and transparent; each of the three longitudinal veins of the forewing forks into 2. Posterior margin of each abdominal segment dark brown. Egg about 0.3 mm long, slightly spindle-shaped, with one short appendage filament, pale yellow. Nymph 2.3-3.3 mm long, yellow-white to gray-green, flat oval, body surface covered with white cottony material.

Life history and habits: 1 generation per year, overwintering as adults in fallen leaves, weeds, bark crevices and dry curled leaves on tree trunks. The following year in March, they begin activity when the temperature reaches 6°C. Mating and egg laying occur from early April to early June, mostly in the morning and evening; during the bud-break period eggs are laid on the buds, several together, and after leaf expansion they are mostly laid on the underside of leaves, with one end of the egg inserted into the leaf tissue. Hatching begins in early May, with the peak in late May. The nymph period is 45-50 days; 5th-instar nymphs cause the most severe damage, and when population density is high the honeydew they excrete makes the twigs and leaves shiny. Emergence occurs from mid-June to July. Adults live about one year; during the day they gather on the underside of leaves to cause damage, and they begin overwintering only in late October when the temperature falls below 0°C. Natural enemies include flower bugs (Anthocoridae), lady beetles, green lacewings, thrips, and others.

Control methods: (1) After autumn, clear fallen leaves and weeds from the orchard and dispose of them centrally. (2) Chemical control, refer to the Chinese pear psyllid. The optimal control period is when overwintering adults have basically finished emerging from dormancy.