Pear small heartworm, also known as oriental fruit moth moth, peach fold heartworm, originated in the Asian continent, is one of the world's important fruit tree pests, but also one of the most important pests in China's major pear and peach producing areas.
The larvae are mostly mothed from the calyx and stem depression, and there is insect feces outside the hole of the early infested fruit moths, and most of the late infested fruit moths are excreted. The larvae moth into the fruit heart, and under high humidity conditions, the area around the borer hole often becomes black and decays and gradually expands, commonly known as "black plaster". The area around the apple borer hole does not change black. Li youguo is easy to fall off when it is killed, and the li fruit is slightly larger and does not fall off, and the moth-eating peach and plum apricot are mostly the pulp near the core of the fruit. First- and second-generation larvae endanger cherry and peach tree young shoots mostly moth into the marrow from the base of the upper petiole, and then migrate to the lignification place, and the borers flow glue and have insect feces, and the infested young shoots gradually wither, commonly known as "folding branches".
Pear-small insecticidal larva
1. Pear small esophatic heartworm damage
Pear small heart-eating leaves are used by larvae to drill frog peach, peach, plum, pear, coriander, begonia, hawthorn, fir handle, heather new shoots, and later drill the fruits of frog, apple, peach, cherry, hawthorn, batch oak, papaya and so on. From the pear tube or apple fruit noodles into the fruit directly into the fruit heart hazard, the formation of "bean paste filling" or "black plaster".
Second, the characteristics of small pear heartworms
Common names: Oriental fruit moth, peach heartworm, needle eye worm, black plaster;
Host: peach, plum, apricot, pear, apple, papaya, hawthorn, etc.;
Pear small heartworm pupae
Hazard characteristics: The larvae eat peach shoots, causing the new shoots to wilt, wilt and sag, and finally longitudinally crack the glue, affecting the normal development of the canopy. Larval borers often enter the calyx and sometimes exit the calyx when ripe. If the moth from the fruit face of the moth, the moth road directly to the fruit heart, the fruit hole is often invaded by saprophytic bacteria, rot and blacken, so it is called "black plaster".
Eggs: flat round, 0.4mm× 12mm central slightly raised, transparent at the beginning, pale yellowish white later;
Pupae: 6-7 m long, hammer-shaped, yellow-brown. There are 2 short spines on the back of the 3rd and 7th segments of the abdomen, and 8 barbs at the end of the abdomen. Cocoon bag;
Pear small heartworm adults
Larvae: Terminal larvae are 10–12 mm long, body flesh red or pink, reddish to pink, orange-yellow abdomen, yellowish-brown head, light yellowish-brown forebreast shield, and lead-brown for the buttocks. The rump has 4 to 7 teeth and dark brown teeth. There are 30 to 40 single sequence rings of the ventral toe hook and 20 to 30 of the gluteal toe hook. There are 3 bristles on the front of the anterior chest air front.
Adults: 5-7 mm in length and 11 to 14 mm in wingspan. Dark brown or grayish black, dull. The forewings are greyish brown with 8–10 pairs of white hook-like twill on the forewing, a distinct white spot at 1/3 of the central near the outer edge, gray-white scales scattered on the wing surface, some stripes on the posterior margin, and about 10 small black spots near the outer edge. The hindwings are light brown , the two wings are mixed , and the outer edge is synthetic obtuse. The feet are grayish brown, and the ends of each tarsal node are grayish white. The abdomen is greyish brown.
Small pear heartworms harm the young fruit
Third, the life habits of small pear heartworms
Pear small heartworms occur in 3-4 generations per year in North China. Old mature larvae overwinter in the soil under the bark of old trees, in the gaps in branches and forks, and in the soil of the root neck, and some under the stones and in the cracks in the walls of the fruit warehouse. The occurrence period of each generation of adult insects: mid-April to mid-June of the first generation, mid-June to mid-July of the first generation, early and mid-July to early August of the second generation, and mid-August to early September of the third generation. The generational period is very uneven, and the generational overlap is serious. Egg stage: 8-10 days in spring, 4-5 days in summer. The larval stage is 10-15 days, the pupal stage is 7-15 days, the adult lifespan is 11-17 days, and it takes about 30-40 days to complete 1 generation.
The first generation of eggs is mainly laid on the back of the leaves of the 3-7 leaves of the peach tree young shoots, and the larvae are mostly endangered in May, and the hatching larvae moth into the young shoots from the base of the 2-3 leaves at the end of the young shoots. The second generation of eggs is mainly from June to early July, most of them are still laid on peach trees, a few are planted on pear or apple trees, and the larvae continue to harm new shoots and begin to harm peach fruits and early maturing varieties of pears and apples. The third generation of eggs is in full bloom from mid-July to early August, the fourth generation of eggs is in mid- and late August, and the third and fourth generations of larvae mainly harm the fruits of pears, peaches and apples. Adults lie still in leaves, branches and weeds during the day and begin to move after dusk, with a strong tendency toward sweet and sour juices and black lights. Adults lay eggs 1-3 days before spawning, lay eggs at night, and individual eggs are scattered. Each female can produce more than 50-100 grains.
Pear small heartworm
Fourth, the law of occurrence
Pear small heartworms occur in 34 generations in the fruit area of Bohai Bay, 4-5 generations in 1 year in the Yellow River Gudao and Guanzhong in Shaanxi, and 6-7 generations in 1 year in all parts of the south. They all overwinter in white cocoons in cracks in bark or crevices in the root-neck soil or in the top sticks and cloth ropes. In Shandong, 4 generations occur in one year, and the overwintering larvae pupate in the upper middle sentence in April of the following year, and the pupal stage varies from 10-20 days. Overwintering adults are at their peak of feathering from late April to early May, laying eggs on the dorsal surface of the peach tip, with an egg stage of 7-10 days. The first generation of larvae occurs in mid-to-late May, mainly in the presence of borers.
Small pear heartworms harm the tenderness of fruit trees
The first generation of adult worms occurs in early to mid-June and lays eggs in peach, pear and apple shoots. The 2nd generation of eggs is 5-7 days old, and the 2nd generation of larvae occurs in mid-to-late June, and the small larvae almost all burrow new shoots, and the large larvae turn to moth infest the young fruit. The second generation of adults occurs in mid-July. The third generation of eggs occurs in the middle of July, most of the eggs fall on pear and apple fruits, and a few fall on peach and cherry shoots, and the egg stage is 4-5 days.
The tender wilts after being slightly endangered
The third generation of larvae occurs in mid-to-late July, and most of the larvae choose pear tubes or apple fruit noodles to enter the fruit directly to the heart of the fruit. The third generation of adult worms occurs in the middle of August in the second sentence. The fourth generation of eggs occurs from mid-to-late August to the first sentence of September, and almost all of them fall on the pear orchard and nearby apple and hawthorn double fruit and fruit surface, and the egg stage is 4-6 days. The 4th generation of larvae occur from mid-to-late August to mid-September, and almost all of them eat the fruits of pears and apples, only the eggs that fall in peach and cherry orchards, and continue to cobalt new shoots after hatching.
Damaged fruit child symptoms
Adult pear heartworms are diurnal and nocturnal, and have a positive tendency to sweet and sour liquids, fruit juices and black lights, especially to sex attractants. The amount of eggs laid by a single female can reach 100, and the eggs are scattered at the 3rd to 7th leaf back, fruit surface, and double fruit at the tip end. The larval stage is 14-18 days and can harm 2-3 shoots or 1 fruit. The pupal site is generally in the cracks in the bark of the branches and the fruit filling, and the pupal stage is 11-15 days. The developmental period from eggs to adults is 30-50 days.
Physical booby traps
Pear small heartworms generally lay a large amount of eggs in years with frequent rain and high humidity, which is seriously harmful, and the occurrence of pear peach mixed planting areas or mixed plantations is heavy. The natural enemies of eggs are pine caterpillar red-eyed bees, and the natural enemies of larvae are rolling moth swollen leg bees, large-legged wasps, mulberry cockroach polyoma bees, dancing poison moth melanoma bees, and curly leaf moth yellow long-distance cocoon bees.
5. Prevention and control methods
There are many pear small heartworm host plants, and the seasonal transfer host is obviously harmful, so we must adhere to the strategy of prevention and comprehensive prevention
Fertilize fruit trees to enhance their disease resistance
1. Agricultural prevention and control
The newly built orchard comprehensively considers the regional characteristics and tree species factors, rationally plans, and advocates large-scale operation. Try to avoid mixed or adjacent planting of apples, pears, peaches, cherries, etc. For tourist orchards or orchard picking, there should be a barrier between the seeds. Combined with gardening before April. Remove the bark cracks, branch roots, cloth ropes in the overwintering larvae, pear small heartworms during the peach damage, every 5-7 days to visit the orchard, combined with summer shears to cut off the new shoots of the victims in time, and properly deal with it.
Do a good job in the prevention and control of pests and diseases in advance
2. Physical prevention and control
During the adult occurrence period, the field hangs a frequency vibration insect lamp, a black light or a sweet and sour liquor or a sexually lure to trap adult insects for monitoring or vagus control. From May to June, the bagging cultivation technology of peach and pear fruits in the whole garden is an effective pollution-free control method for the prevention and control of pear small heartworms.
In the spring, the skin of the tree can be carefully scraped to eliminate the overwintering larvae; the single-planted pear garden, in the first and second generation of larvae, artificial removal of the pest fruit; peach pear and plantation, timely removal of the affected peach shoots, reduce the source of insects, reduce the pest source, alleviate the harm to the pear in the later stage; planting lure plants, the test proves that the scattered planting of plum trees around the pear orchard, the inducement of small pears to lay eggs in the plum fruit.
Prune pest and diseased branches
In Beijing, in early May, more than 95% of the plum fruits are eaten by pear small heartworms, before its fruit removal, timely removal of all the affected plum fruits, centralized destruction, can effectively reduce the number of insect mouths in that year; black light booby traps; before wintering fruit removal (northern fruit areas are generally before mid-August), on the main trunk of the main branch, the use of booby grass or sack pieces to trap the larvae that have overwintered.
When building a garden, try to avoid mixing with peaches and apricots or planting at close range, and prevent the pears from being transferred to each other between the hosts; set up sweet and sour liquid (brown sugar: vinegar: white wine: water = 1:4:1:16) in the orchard, add a small number of enemy insects, and trap the adult insects. Hanging frequency vibration insecticidal lamps from mid-March to mid-October can be effectively booby-trapped.
Prune in winter to remove damaged branches
3. Biological control
The 5-5-5 bee release method (that is, 50,000 heads per 67m2, that is, 50,000 heads per 67m2, that is, the 5-5-5 bee release method) wasp release in the field during the spawning stage of each generation of pear heartworms (that is, 5-5-5 bee release method) wasp release in the field to lower the insect population base in the early stage of the peach orchard and reduce the pressure of the prevention and control in the later stage of the pear orchard. Pear minimise silk technology: the use of adult mating requires the release of pheromones to find mates biological habits. The use of high concentrations of long-term pheromone interference, so that the male insects can not find the female insects, to achieve the purpose of unable to mate and lay eggs to protect the orchard. This technology is simple and convenient to use, while reducing pesticides or even eliminating the need to use pesticides, in line with the development of food safety.
High quality pear hanging fruit performance
Red-eyed bee control technology: taking the core of pear small heartworm as a monitoring method, after the peak of the moth l ~ 2 days, artificially release the pine hair red-eyed bee, 1.5 million heads per hectare, 300,000 heads / ha each time, divided into 4-5 times, can effectively control the pear small heartworm as a pest.
High quality peach hanging fruit state
4. Chemical control
At the spawning stage and larval stage of each generation of adult insects in pear orchard, chlorite benzocarbin gum, oxycarbacene, juvenile extermination, methrin, trifluorothrin, high-efficiency cypermethrin, methyl vitamin salt and other rotational alternate spray control 4-8 times. Prevention and control time and indicators: the egg and fruit rate survey began in August, 1% to 2% began to spray, and after 10-15 days, the egg and fruit rate reached more than 1% and then sprayed. Types and concentrations of agents: 2.5% cypermethrin emulsion 2 500 times liquid, 10% cypermethrin 2 000 times liquid and 40% water amine thion 1 000 times liquid, 1.8% avermectin 3 000 to 4 000 times liquid.
High quality plum hanging fruit symptoms
Remarks: Common pear heartworm hazards mainly harm peach trees, pear trees, plum trees and other fruit trees, first the fruit tree is tender, and then the fruit is endangered. After the opening of spring, the flower buds are not spreading leaves and fruits at a diameter of 1 cm, and they are controlled at two key times!