Control of cherry pear small heartworms

Pear small heartworm (Grapholitha molesta Busck) referred to as "pear small", belongs to the lepidoptera small leaf curling moth family, also known as pear small borer fruit moth, oriental borer fruit moth, mainly endanger pear, peach, peach, apple, large cherry and other fruit trees, especially fruit trees mixed planting orchards are more serious, today we focus on understanding the harm of pear small heartworms to large cherries and control methods.

First, the harm of large cherry pear small heartworm:

Larvae as a pest of young shoots, when pests mostly from the base of the petiole at the tip of the new shoots into the marrow from top to bottom to eat, after the larvae moth into the new shoots, the outside of the borer hole has insect droppings and gum flowing out, the leaves above the borer hole gradually withered, to dry up, at this time the larvae have been detached or transferred from the tip, each larvae can moth 3 to 4 new shoots, most of the damaged new shoots are hollow, and leave a hole, the new shoots gradually wither, there is worm feces discharged outside the borer holes, and often glue, and then the new shoots dry up and droop.

Second, the occurrence of small pear heartworms　

Occurs 3 to 4 generations a year, with old mature larvae overwintering in cocoons in bark crevices and other hidden places. The overwintering larvae begin to pupate in early spring and mid-April, and the first generation of larvae begins to infest in mid-to-late May. The second and third generations of larvae are harmful to cherries, and from early July to early September, it is a period of severe harm. In particular, the occurrence of severe damage in the nursery, years with more rain and high humidity are conducive to adult spawning, and the occurrence of harm is aggravated. The insects lie still in the leaves, branches and weeds during the day, and begin to move after dusk, and have a strong tendency to sweet and sour liquids and juices and black lights. Adults lay eggs 1 to 3 days in the early stage, lay eggs at night, and individuals are scattered. Each female can produce 50 to 100 grains.

Third, the control method of large cherry pear small heartworm

1. Artificial control: scrape off the coarse skin before germination in early spring and burn it in a concentrated manner; in August, bundles of grass are tied to the main trunk to induce overwintering larvae, which are removed and burned in winter. In the spring and summer, it is cut off in time to be burned by the moth tips.

2. Physical control: use black light to trap and kill at night during the occurrence of adult insects, or hang sweet and sour sprays and sexual attractants in the canopy.

3. Drug control: spray control is in the egg laying stage of adult worms or the incubation period of larvae. After the cherry blooms until before the fruit is harvested. Spray when the orchard moth rate reaches 0.5% to 1%. Agent type and concentration: 2.5% cypermethrin emulsion 2500 times liquid, or 10% cypermethrin 2000 times liquid and 40% water amine thiophos 1000 times liquid, or 1.8% avermectin 3000 ~ 4000 times liquid, or 0% peach spirit emulsion 2000 times liquid, or 25% urea No. 3 suspension 1500 times liquid control.