Hello fruit grower friends, Xiaobian has come to popularize the laws of plant diseases and insect pests and control methods. Doing a good job in the prevention and control of pests and diseases is a very important link in the planting process and is of great significance to improving yield. Let's take a look at the peach tree small heartworm to be introduced today!
Peach small heartworm is an insect in the genus Small heartworm in the family Lepidoptera. Also known as the peach borer fruit moth. Fruit tree pests, such as peaches, apples, pears, bonuses, hawthorns and sour dates. Adults are grayish or greyish brown , females are 5 to 8 mm long , have a wingspan of 13 to 18 mm , and males are slightly smaller. In orchards without bagging, the victims are often severe. So what is the harm law of peach heartworms? How to prevent scientifically?
The occurrence of peach heartworms is as follows:
1. Overwintering larvae. According to the multi-year survey, peach small heartworms overwinter in the soil under the canopy with old mature larvae forming round winter cocoons, and more than 95% of the wintering cocoons are distributed within 2m of the trunk circumferential figure. The vertical distribution is 75% in 0-5 cm soil layers and 25% in 6-10 cm soil layers. In mid-to-late May, when the average temperature reaches above 17 °C, the larvae begin to emerge. The amount of excavation depends on the amount of descent. From the survey results, it can be seen that the rain from late May to early June is relatively young, and the amount of moths throughout the year is significantly smaller, indicating that the rainfall is conducive to the concentration of larvae.
2. Adults. The change of rainfall has a significant impact on the number of feathers of peach heartworms, and the peaks of moths of different degrees occur when the relative humidity of the air is large after the increase in rainfall. Rainfall from May to June is the dominant factor affecting the early and late feathering of adult insects. The overwintering generation of peach heartworm moths begins around mid-May, enters the peak period of moths at the end of mid-June, enters the peak period of moths in late June, and the last sentence in July is the end of the peak period. The first generation of moths is not neat, and the peak of the moths is in early August. The peak of the overwintering moth is about 40 days from the peak of the first generation of moths, and the peak of the moth is not obvious.
3. Eggs. According to field observations, peach heartworms mostly lay eggs at the calyx of the fruit, the eggs are orange-red, and the egg period is about 8 days. Varieties with more hairy hairs in the calyx of the fruit (Huang Marshal, etc.) have the largest egg volume, and varieties with less fur in the calyx part of the fruit (Guoguang, etc.) have the largest egg volume. The peak period for the first generation of peach heartworms is in the late June (i.e., about 10 days after the wheat harvest) and the peak period is from the end of the second sentence of June to the beginning of the first sentence of July. The second generation spawning peaks in early to mid-August.
4. Larvae. According to field observations, the decomposed larvae moth in the middle and lower parts of the selected fruit on the fruit surface, and transparent juice flows from the frog fruit hole. The larvae are infested in the fruit for about 20 days. The first generation of larvae is at its peak in mid-July to mid-August. Observe the borer larvae in the box, and the larvae defruit and form a summer cocoon in early August. After the middle sentence in August, the larvae that delay fruit loss overwinter in wintering cocoons. By investigating the egg and fruit rate, the time of drug control on the tree can be determined, and when the first adult is induced, the egg and fruit rate is investigated every 3 days When the egg and fruit rate reaches 1%, the drug is started on the tree. The results of the survey for many consecutive years showed that the egg-fruit rate reached 1% time, the first generation was in late June, and the second generation was in late July to early August.
Mastering the occurrence law of peach small heartworms, we have seized the critical period of prevention and control. Accurate monitoring and reporting is the key, under the guidance of monitoring and reporting, take the prevention and control under the tree as the mainstay, the tree prevention and control as a supplement, the treatment of 1 generation, the control of 2 generations of artificial, physical prevention and control and pharmaceutical control combined methods, you can achieve a more ideal prevention and control effect.
1) Seize the right time on the ground to eliminate the adult insects before going up the tree. At the peak of larval emergence, when the first male moth is lured, it is the appropriate period for ground control. Timely spray within 2m around the trunk, as well as the key areas around the fruit cellar and the fruit drop purchase point, spray the ground evenly with 50% octyl thiophosphorus emulsion 300 times liquid per mu, and immediately after application. Re-administration after 1 month of intervals can basically control the hazard. In addition, after the peak of the emergence of overwintering larvae, the soil under the canopy is 6-9 cm thick, or the mulch film under the canopy can effectively prevent the emergence of adult insects.
2) Grasp the tree to control the appropriate period and eliminate the larvae in front of the borer. When the amount of moths reaches its peak 5-7 days, or when the egg-fruit rate reaches 1%, spray the tree, mainly the calyx of the fruit. Available with 20% permethrin 2500x solution or 48% chlorpyrifos 1200x solution plus 2. 5% high efficiency cypermethrin 2500 times liquid.
3) Fruit bagging (finished before adult eggs are laid), sexual attractants to trap adult insects and other methods of control.
Recently, green food has become more and more popular, and fruit growers can also use biological control to reduce insect pests. There are several kinds of parasitic wasps of peach heartworm, especially the peach small early abdominal cocoon bee and the Chinese tooth leg wasp have a higher parasitism rate. The peach beetle-bellied cocoon bee lays eggs in the peach eggs, parasitizes the larvae in the peach larvae, and is eaten when the peach overwintering larvae emerge as a cocoon. Therefore, at the peak of the generation of adult insects, small parasitic wasps of peach can be released. During the initial incubation of the larvae, bacterial pesticides (bt emulsions) are sprayed to cause the peach to die of disease. Peach small sex attractants can also be used to trap adults during the overwintering generation.