Pear small heartworm referred to as pear small, also known as pear small fruit moth, oriental fruit beetle moth, pear ji heartworm, peach folding worm, small heartworm, peach heartworm, small leaf curling moth family. Pear small heartworms have occurred in various fruit production areas in China in recent years, and tend to be serious.
In our area peach, pear and large cherry on the new slightly more harmful, found that it is too late to break a little and then go to control, seriously affecting the normal growth of fruit trees, small pears in addition to harming pears, peach trees, but also harmful to plums, apricots, apples, hawthorn, etc., seriously affecting the quality of fruit and pear fruit yield, bringing great losses to fruit farmers. Here I would like to introduce to you the occurrence law and control methods of pear small heartworms:
The pear is small and the peach is slightly more harmful
First, the characteristics of the hazard
Pear small heartworm mainly uses larvae to eat the new shoots and fruits of pear, peach and apple trees, often mothed into the branches from the base of 2-3 leaves at the tip end, and the first end of the infested tip withers, and then the gum flows out from the borer hole, drying up and drooping. The pear fruit is mothed into a relatively small hole, and after entering the fruit, it goes straight to the heart of the fruit and eats the seeds. The defoment hole is black plaster-like.
Pear small old ripe larvae
Second, the law of occurrence
The number of generations that occur in a year varies from region to region, with 3-4 generations a year in most areas and 4-5 generations in the Yellow River Gudao area. Mature larvae overwinter mainly in cocoons in the cracks in the bark of the tree body, and can also overwinter in the surface soil at the base of the trunk. Pear heartworms have obvious host metastasis and infestation sites, from harming peach shoots to harming pears or apples, as well as peach fruits. The first to mid-May of each year is the peak of the occurrence of adult insects, with a single egg scattered, and each female laying more than 50 to 100 eggs. The first generation of eggs is mainly laid on the back of the third to seventh leaves of the young shoots of the peach tree.
Hatching larvae moth into the young shoots from the base of the leaf at the tip of the young shoots. The second generation of eggs mainly occurs from June to early July, most of the eggs are still laid on peach trees, a few are produced on apples, pears, large cherry trees, larvae continue to harm new shoots, and some begin to harm peach fruits and early ripening apples, pear fruits. The third and fourth generations of larvae are mainly harmful to pears, peaches, and apple fruits. Adults lie still in leaves, branches and weeds during the day, and are active after dusk, with a strong tendency towards sweet and sour solutions, juices and black lights. Pear small heartworms are generally in rainy years, high humidity, adult eggs laying a large number, serious harm, drought years are lighter. There are many types of natural enemies of pear small heartworms, including red-eyed bees that parasitize eggs, small cocoon bees that parasitize larvae, and blunt bees.
Third, the prevention and control methods:
1. Artificial prevention and control
1) When building a garden, try to avoid peach, apricot, plum, cherry, apple and pear mixing.
2) Before germination in early spring, carefully scrape the bark and concentrate on deep burial or burning.
3) Before the last larvae are shed, tie grass or sack pieces to the main trunk and main branches to lure the wintering larvae.
4) During the larval damage period, cut the affected peach shoots in time and remove the insect fruit to eliminate the larvae in it.
2. Prevention and control of natural enemies
There are many types of natural enemies of pear small heartworms, such as red-eyed bees, black egg bees, tiger beetles, grasshoppers, spiders, etc., and attention should be paid to protecting these natural enemies. Where there are conditions, it can also be artificially multiplied.
3. Ecological prevention and control
Each acre of orchard hangs 33 misty silks, each of which hangs on a firm branch 2/3 of the height of the tree. The principle of the lost silk is to interfere with the information recognition of the small heartworm of the pear, so that the male and female insects "lose" their way and cannot find each other, thereby blocking the mating of adult insects and completely preventing larval harm. Because of its environmentally friendly and efficient characteristics, pear small sex obsession technology has become a common technology in many countries in the world to replace or greatly reduce the use of chemical pesticides to control pear small heartworms.
Pear little fan to silk
Booby traps with sweet and sour solutions. When adults are continuously active in the field, that is, from May 6 to September 10, the sweet and sour solution is hung in the field. Specific method: according to the ratio of sugar: vinegar: liquor: water = 5: 20: 2: 80 to prepare the sweet and sour liquid, the prepared sweet and sour liquid, into a diameter of about 20 cm, about 8 cm deep plastic basin, each pot 500-650 mI, above the basin mouth equipped with a rain cover or placed rainproof plastic sheet, hanging in the shade of the tree, every 667 m² 10-16 places.
Sweet and sour solution trapping
The cultivation of pear small heartworms is advocated in areas with serious pests, and pear fruit bagging can effectively prevent the harm of pear small heartworms.
4. Chemical control
Combined with Qingyuan to kill overwintering eggs. When the buds germinate, the whole garden is sprayed with 3-5 baume degrees of stone sulfur compound, and the tree tray and trunk skin should be sprayed tightly.
According to the insect situation monitor, the medicine is used on the tree at the right time. Medication begins at the end of April and the beginning of May each year, with the option of spraying high-potency cypermethrin or chlorpyrifos emulsion or methylphenidate for control. Spraying the above drugs seven to ten days after the first spray can effectively control the occurrence of small pear heartworms. It should be noted that the small eggs of the pear are laid on the back of the leaves, so the spray head should be turned upwards when spraying to kill the eggs on the back of the leaves. The larvae burrow down from the top of the new shoots, so the new shoots use a sprinkler to spray down the drug to kill the larvae.
Author: Zhu Zhen Responsible Editor: Bai Cha Qinghuan