From April in spring to October in autumn, it is a period of high incidence of pear heartworms (also called heartworms and heartworms) in orchards and fruit trees. For the prevention and control of pear heartworms, many fruit farmers usually do not pay attention to targeted prevention in advance, once they hatch from the eggs into the larvae into the young new fruit of the fruit tree or drill into the young fruit inside, most of the fruit farmers want to prevent and eliminate them It is very difficult, and even often helpless at all, because they are hidden in the new and fruit, you want to kill them by insecticide to the fruit tree, which is very difficult to do - the insecticide liquid is difficult to contact them.
Remarks: From mid-April to late May every year, the peak period of the first generation of larval damage of pear heartworm (from mid-April to early June, at this time, the peach tree is the most seriously damaged), in addition, from June to October, there will be 2-4 generations of insect pests ranging from pear heartworm (insect pests will gradually move from peach trees to apple trees, Pear trees and other fruit trees continue to be harmed, the most serious damage at this stage is the fruit trees other than the peach tree Xinxiao and fruit), generally 3-4 generations of pear heartworms can occur in the northern fruit tree planting areas a year, and 5-6 generations of pear heartworms can occur in the southern fruit tree planting areas a year, and each generation of pear heartworms can accumulate and increase from generation to generation, and continue to damage the young and new fruits of fruit trees for a long time, until the weather becomes cold in October and November will gradually stop (the pests begin to prepare for overwintering and dormant at this time).
I believe that the vast majority of fruit farmers have a headache in the prevention and control of pear heartworm every year, because they do not understand the characteristics of the insect pest, and usually do not pay much attention to it before the occurrence of the pest, and wait until the larvae drill into the new slightly to cause the new slightly wilted and die, and wait until the larvae drill into the young fruit to cause the fruit worm eye rot, at this time I don't know what to do.
In today's article, I will first tell you about the insect pests of pear heartworms, and tell you what insect characteristics it has before controlling pear heartworms. If you don't understand the occurrence law and characteristics of insect pests, how can you prevent and control insect pests?
The first point: the occurrence of pear heartworm insect pests is closely related to the mixed planting of a variety of fruit trees in the orchard
Where there are peach trees, pear trees, apple trees and other fruit trees mixed (including the surrounding area) of the orchard, generally the pear heartworm in this orchard will be more serious, on the contrary, if you only plant one kind of fruit tree in your orchard, then the occurrence of pear heartworm on your fruit tree will be relatively light.
Because pear heartworms will move from different fruit trees to each other, for example- For example, sometimes you see a young and young fruit on the fruit tree being broken and withered by the pear heartworm, but you often can't find the larva inside when you peel off the wilt, this is because the larvae has been transferred to other fresher and more tender new trees or transferred to other fruit trees after biting the new and then continues to "destroy"!
The second point: the occurrence of pear heartworm pests is directly related to climatic conditions (temperature and humidity).
Generally speaking, from the beginning of April to the end of September (in some areas to October) in the spring, if there is more rainy weather and high humidity in the orchard, then the occurrence of pear heartworms in the orchard will be relatively serious.
Because as long as the weather temperature reaches the temperature range of 15-30 degrees (the most suitable temperature is 24-29 degrees), and the relative humidity of the air reaches more than 70%, then the adult worms of the pear heartworm will greatly increase the activity of reproduction and egg laying in this suitable temperature and humidity range, and at the same time, the pear heartworm hatches from the eggs into larvae. The growth and development rate from larvae to pupa hatching will be accelerated, and the growth and development time of each generation of pests will be greatly shortened, resulting in more (cumulative generations) of pear heartworms with different insect morphologies in the orchard, resulting in more serious pear heartworm pests in fruit trees.
The third point: the degree of damage of pear heartworm is related to the characteristics of adult and larvae
The adult of the pear heartworm is a winged moth that can fly, and its larvae are also the main force that damages the new fruit trees and fruits. Although the adults of Pearworm heartworm do not cause great harm to the new fruits and fruits of fruit trees, the larvae of the new fruits of fruit trees are closely related to the mating and oviposition of adults.
The adults (females) of the pear heartworm will concentrate on the back of the 3-8 fresh leaves on the top of the fruit tree for concentrated oviposition (after the eggs hatch into larvae, they will directly burrow into the tender and slightly injure the new slightly, causing the new slightly hollow to break and wither), but there will also be some females who will concentrate on the oviposition on the surface of the young fruit (after the eggs hatch into larvae, they will directly burrow under the peel and harm the fruit, resulting in wormholes on the fruit surface, If you want to check whether there are pear heartworms on your fruit trees or check whether the pests of fruit trees are serious, you should focus on checking the back of the tender pieces at the top of the new shoots and the calyx depressions of the young fruits.
In addition, the adults of the pear heartworm have a strong diurnal nocturnal nature, and generally cannot hide their activities during the day, and will not come out to carry out activities (such as laying eggs at night) until the evening and night (especially in the first half of the warm and humid night);
Fourth, the type of fruit tree and the part of the fruit tree that the pear heartworm harms at different times are different
From the end of March and the beginning of April to the end of September and the beginning of October every year, 3-6 generations of pear heart-eating insect pests can occur in fruit tree planting areas in different regions throughout the year (basically one generation can be reproduced in a month), and generally fruit trees in southern provinces can occur about 5-6 generations throughout the year, and fruit trees in northern provinces can occur 3-4 generations throughout the year. Generally, the larvae of the first and second generations mainly damage the new shoots of fruit trees, and the larvae after the third generation mainly damage the young fruits on fruit trees.
Taking the orchards of mixed peach, pear and apple trees as an example, the first generation of pear heartworms begins to lay eggs and reproduce around mid-April, which mainly harms the new shoots, new leaves and new leaves of peach trees, resulting in the withering of new shoots and new leaves on peach trees. The second-generation larvae that breed from mid to late May to early June will not only continue to damage the tender and young fruits of peach trees, but also the adults of the pear heartworm will successively transfer to the surface of the young and young fruits of pear trees and apple trees for oviposition and propagation, and the larvae will continue to damage the new and young fruits.
After that, the third generation of larvae that breed from mid to late June to early July, the fourth generation of larvae from the end of July to early August, and the fifth generation of larvae that reproduce from mid to late August to early September will accumulate and accumulate from generation to generation on orchards and fruit trees, gradually increasing the damage to new fruit trees and young fruits. That is, from June to September every year, this is the most serious period of pear pest infestation in the orchard and on the fruit tree (don't wait until this time the fruit tree pest is serious before thinking about spraying pesticides to control pear pests, because the larvae at this time have already penetrated into the fruit, and the pesticide control effect will be very poor or even completely ineffective).
The fifth point: we must correctly learn the detection method of pear snack heart insect pest and the judgment of insect pest symptoms
To control the pear heartworm in the orchard, it should be checked early in the spring, prevented as early as possible, and the correct location should be checked. When the pear heartworm damages the fresh and young fruits on the fruit tree:
(1) Adult oviposition inspection site: when the female of the pear heartworm lays eggs, it is generally mainly concentrated on the back of 3-8 leaves from the top of the new fruit tree, and we can focus on checking this position when checking whether there is a pear heartworm on your fruit tree in the spring in March and April, and you can know the degree of damage to the insect pest in the later stage by looking at the early oviposition.
(2) The larvae damage the new part: the larvae that have just hatched from the eggs are generally mainly from the petiole of the 2nd to 3rd leaf of the fresh new top of the fruit tree/ The base of the leaf peduncle is drilled into the new slightly, and when the larvae drill into the new later, it will leave insect feces in the place of the leaf base cavity or cause the new worm hole to flow outward, and cause the new slightly noon wilting or cause the new leaf to be slightly yellow and white and gradually wither and break, we should focus on checking whether there is a larvae in this new part of the new part when the hatching peak period of the first and second generation larvae in the spring (the 1-2 generation larvae are mainly harmful to the fruit tree).
(3) The larvae damage the young fruit parts: most of the larvae of the pear heartworm are the fruit stalks of the young fruits from the fruit trees/ The fruit stalk part is drilled into the inside of the young fruit, and when the larvae drill into the inside of the young fruit, it will leave a small wormhole on the surface of the fruit, and the wormhole part on the surface of the fruit will also have the phenomenon of outward gum and worm feces (the wormhole part will be black or rotten when the air is very humid), we should focus on checking whether there is larval borer drilling phenomenon in the young fruit peduncle part of the tree during the peak hatching period of the 3rd and 6th generation larvae after May in spring (the larvae after the 3-4 generations are mainly harmful to the fruit on the fruit tree).
The sixth point: we must grasp the best control nodes and control points of pear heartworm
For the control of pear heartworm, the earlier the detection of the incidence of insect pests, the earlier the prevention and control effect, the better, when the new slightly tender egg insect rate in the orchard reaches 0.5-1%. The best time node for the prevention and control of pear heartworm is the peak period of concentrated oviposition of adults (females) at each stage and the early stage of concentrated incubation of larvae at each stage, or in mid-April, early May, mid-June, early July, mid-August, early September, at this time, chemical control + agricultural control + physical control + biological control pear heartworm pests and the most effective control, the best insecticidal and insect control effect, and the focus of prevention and control is to concentrate on eliminating the adults who lay eggs and killing the newly hatched larvae.
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