Pear Burrs

Pear Burrs

Pest Type: Fruit Pest

Row: Equine – Homoptera

Family: leaf flies – Psyllidae

Most harmful in the steppe and forest-steppe. Damages the pear.

Adults 2.5-3 mm in size, body-color from black-orange (summer form) to dark brown, antennae pale yellow; mesoscutum orange with yellowness in the corners; two pairs of transparent wings; hind legs hopping, pale yellow, thighs light brown; the abdomen is dark brown. The egg is 0.3 mm in size, oval, with a short stalk; freshly deferred – milky white, hereinafter – sweet orange. The larva is flat with a rounded belly, first light yellow, later – from yellow-green to brown. Nymph 1.6-1.9 mm long, oblong, brownish-green, antennae with 7 segments, cross-winged cap. Adults hibernate in crevices and cracks of tree bark, under fallen leaves. They leave early in spring at an average daily temperature of minus 2-3 ° C (in the south – in late February – early March, in the forest-steppe – in mid-March).

Females overwintered live from 30 to 45 days. During this time, in several doses with an interval of 5-6 days, they lay from 400 to 600 eggs, placing them in a chain at the base of the kidneys, on the pedicels. The next generations lay eggs on leaves in groups of 20-30 pieces. After 8-10 days, larvae are reborn. They penetrate into the buds, which bloom, later pass to pedicels, young shoots, petioles of leaves, ovaries. After five molts, they turn into an image, which coincides with the end of the flowering of the pear. The duration of development from an egg to an adult insect is approximately 17-25 days. 2-3 days after winging, leaf clowns mate and begin to lay eggs, giving rise to the development of the second generation. The fertility of summer generations is 700-1200 eggs with an average daily laying of 20-80 eggs. In the forest-steppe zone, pear tinnitus develops in four, in the south – in five generations, overlap each other. For the development of one generation, the sum of effective temperatures of 400 ° C is required with a lower threshold of 6 ° C.

Damage is caused by larvae and adults, sucking juice from buds, leaves, pedicels, shoots, and fruits. Damaged organs are underdeveloped, leaves and ovaries fall, the fruits become ugly and stiff, branches dry out; general weakening of trees occurs. Thorns produce a significant amount of sticky sugar excrement, which, with the mass number of pests, covers all trees and the soil of trunks. Saprophytic sooty fungi develop on the contaminated surface. Dry and hot weather contributes to the development of the pest.

The pear is also damaged by a large pear leaf-leaf, which, according to the main features of development and harmfulness, does not differ much from pear tinnitus.

The number of pests is limited by gold lies, muhisirfids, ground beetles, predatory bugs, spiders.

Protective measures. Late autumn plowing of fallen leaves and plant debris. Cleaning strains of apple trees from moss, lichens and dead bark. The criterion for the number of tinkers that determines the advisability of spraying with insecticides is more than 10 colonies per 100 shots, or 10 colonies per 100 sheets, or 5 colonies per 100 flower rosettes. Leaf-leafs of subsequent generations dies after the treatment of trees with insecticides to protect them from moths and other pests.