Dangerous Pear Fruit Gall Midge

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Pear fruit gall midge, which damages young pear fruits, is found almost everywhere. Fruits, attacked by voracious larvae, first grow at an incredible speed, significantly outstripping healthy ones in size. And after the larvae, which have eaten them entirely, begin to move into the soil, the brown damaged pears shrivel and crack, and after a while they completely dry out. If you do not fight this garden pest, crop losses can easily reach 50 - 90%. And too severe damage to fruit trees can generally reduce the yield to zero

Meet the pest

The size of dark gray adults of pear fruit gall midges is about 3-4 mm. All of them are endowed with yellowish-brownish long antennae. They are also characterized by simplified wing venation. The legs of these garden pests are long and thin, and the oral apparatus is reduced. An adult insect is a tiny mosquito, or rather a mosquito-like fly.

Light yellow larvae of pear fruit gall midges grow up to 4 mm in length. Their body is narrowed to the tips, slightly elongated and consists of thirteen segments. Also, the larvae are characterized by the absence of legs and separate small heads.

Pupae overwinter at a depth of five to ten centimeters in the soil. Overwintered parasites begin to emerge at the stage of separation of tiny buds, otherwise called the "rosebud" stage.

Mating females start laying eggs almost immediately. They do this until flowering. With the help of needle-shaped long ovipositors, females lay twelve to twenty eggs in each bud. It happens that one bud can contain up to hundreds of eggs, however, in this case, they will be laid by several females.

After about four to six days, voracious larvae are reborn. They instantly penetrate into the receptacle and develop further there, eating away at the same time the important generative organs of plants. It will not be difficult to find ovaries infested with parasites - they are characterized by abnormally large sizes, since from the first days of penetration of harmful larvae into them, they noticeably accelerate their growth. And by the time the development of these pear enemies is completed, the ovaries are often eaten out entirely, which in turn provokes drying out, as well as cracking of young fruits with their subsequent fall.

Most often, the development of larvae takes from thirty to forty days. In June, throughout the month, they move into the soil, leaving the fruits they love. There, approximately until September-October, they remain in rather dense cocoons, and with the onset of autumn they pupate and continue to stay in the soil until spring. For a year, a single generation of pear fruit gall midges has time to develop. These parasites harm mainly at the stage of larvae.

By the way, outwardly, pear fruit gall midges are similar to flower blackberry gall midges, the larvae of which live in underdeveloped blackberry and raspberry fruits.

How to fight

Both in the near-trunk circles and in the aisles, it is necessary to carry out thorough spring and autumn tillage. And cultivation is carried out during the transition of larvae that have completed feeding into the soil. The ovaries damaged by voracious scoundrels should be promptly collected and destroyed.

During the summer, pests of adults are caught on glue traps, and in the case of mass reproduction of pear fruit gall midge, insecticide treatments are carried out. This is done, as a rule, at the stage of separating the buds. Before flowering in spring, trees are allowed to be sprayed with preparations such as Chlorophos, Nexion, Antio, Karbofos, Phosphamide, Metaphos, Metathion, Zolon, Dursban or Gardona. …

Some gardeners poison the soil under the crowns of severely damaged fruit trees with hexachlorane.