Heart-eating worms
Peach small heartworms mainly harm pomegranates, apples, peaches, pears, red flowers, hawthorns, dates and other fruit trees. Peach small heartworm larvae are generally mothed in the middle and bottom of the fruit, and the surface of the fruit has needle-sized bores, showing black-brown notched spots, surrounded by a thick green, often accompanied by teardrop-like pectin spillage, and a white waxy film after drying up. Because the borer hole is small, it is not easy to find. The fruit occurs for 4 to 5 days, and the fruit appears a round light red halo of about 2.5 cm in diameter, and changes with the growth of the fruit
It is peachy red, and the red halo of the dorsal fruit surface is more pronounced. The larvae feed on the fruit, and the borers feed on the surface of the peel or core of the seed, and the worm path is curved and contains reddish-brown insect feces. The young fruit stage is harmful, the fruit generally turns yellow and falls off, and occasionally hangs on the tree. After the larvae mature, they form fruit removal holes 3 to 4 days before fruit removal, and some of the feces are excreted from the fruit. Part of the stool often adheres to the defomentation hole and is easily detected.
Morphological characteristics
(1) Adult worms. Females are larger, 7-8 mm long and 15-18 mm winged. Males are smaller, with a body length of 5-mm and a wingspan of 13-15 mm. The whole is grayish white to greyish brown, and the compound eyes are reddish brown. The female's lip must be long and straight forward, and the male's lip must be shorter and upward, which is one of the main features to distinguish between male and female. Adults have large, nearly triangular blue-gray spots near the central leading edge of the adult forewings, and 7 to 8 clusters of diagonal scales of melasma or bluish-brown near the base and middle. The hindwings are grey with long marginal hairs and light grey. 1 wing is thin male and 2 females.
(2) Eggs. Oval or barrel-shaped, the egg is orange-red in the early stages, the gradient is dark red, and the black skull of the larvae is visible on top of the eggs in the early stages of hatching. The top of the egg is circumferential 2 to 3 times"!" Spiny hairs, the surface of the egg shell has an irregular polygonal mesh marking.
(3) Larvae. The juvenile larvae are yellowish or white. Nearly mature body length 13-16 mm, peach red, larval body length, size, color often due to the host plant and other factors slightly different. The larvae have a lighter abdomen, no rump, a yellowish brown head, a yellowish brown to dark brown forebreast shield, and a yellowish brown or pink rump plate. After the larvae mature, they are cocooned pupae, and the cocoon can be divided into two types: winter cocoon and summer cocoon. The winter cocoon is small, flattened and round, 2-3 mm long, the cocoon silk is tight, and the larvae are waxy pupae in a "c" shape. The summer cocoon is large, long spindle-shaped, 7 to 13 mm long, the cocoon silk is loose, and the larvae are present
A "glyph pupae."
(4) Pupae. Pupae are initially yellowish-white and gradient grayish-black. The ends of the feet and antennae are free, and the pupa wall is smooth and spineless.
Regularity of occurrence
Peach small heartworm is widely distributed in the northern fruit area north of N31 and east of E102 in China, and is one of the main pests in the fruit sound area of China, which occurs in 1 to 2 generations a year in Shandong region, with old mature larvae in the soil under orchard trees, embankments, fruit farms, seed layer sand piles, fruit tree root neck cocoons overwintering. The study found that the wintering larvae in Shandong began to be excavated in mid-May, and the peak period of excavation was from late May to the end of June. After the peach small heartworm was unearthed
Mainly in the shade of the canopy, stones, soil blocks, fruit tree roots, weeds, debris and other places to make summer cocoons and pupate. Adults often emerge diurnally and nocturnally after feathering, usually laying eggs after 2-3 days, and the spawning period of each female is about 15 days. Hatching larvae often crawl on the surface of the fruit to select the appropriate part of the borer damage. The first generation of larvae has a period of 22 to 29 days in the middle of the fruit, and the adults begin to appear in late July, ending in the second sentence of September, and the peak period is generally in mid-to-late August. The second generation of larvae has a period of 14 to 35 days in the fruit, starting to shed fruit in late August at the earliest, and peaking in mid-to-late September. The adult generations of peach heartworms overlap severely, resulting in indivisible algebraic differentiation. Its occurrence is closely related to local temperature, humidity, host plant species, etc. Overwintering larvae excavation, pupalization, feathering, egg laying, etc. all require higher humidity, adult insects need to be moist soil when they emerge, and the larvae cannot be unearthed in the early days of dry weather, and after rain
The number of excavations has increased significantly, so it is necessary to make reasonable adjustments according to weather conditions. The amount of rainfall in May and June is the dominant factor affecting the time and number of feathering of adults in the overwintering generation.
Prevention and control measures
The prevention and control of peach small heartworms should do a good job in forecasting and forecasting, and adhere to the original principle of "under the tree as the mainstay, the tree as the supplement, strict prevention of the 1st generation, and control of the 2nd generation", which can play a multiplier effect with half the effort.
Agricultural prevention and control
Before the overwintering larvae emerge and defoliate, pay attention to removing weeds and mulchs from the lower part of the canopy, and remove the insect fruit in time and do centralized treatment. In recent years, with the promotion of wide-row dense planting cultivation and the follow-up of corresponding horticultural measures, wide-width mulch film and floor cloth covering the tree disc can effectively prevent or reduce the probability of successful feathering and spawning of overwintering adults, and the effect is good.
Physical prevention and control
(1) Fruit set glory. During the occurrence of peach small heartworms, it is necessary to remove the insect fruits in time and concentrate on drug treatment. Fruit bagging can be performed before the adults lay their eggs to prevent the larvae from drilling into moths.
(2) Enticing prevention and control. In The middle sentence of May hangs insect trap lamps, frequency vibration insecticidal lamps, sweet and sour liquor, etc., which have the effect of monitoring and poaching peach small heartworms.
Chemical control
(1) Sprinkle poisonous soil or spray on the ground. 15% poison mantis granules 2 kg, or 50% octyl thiophos emulsion 0.5 kg combined with fine soil, sand and other 15-25 kgil to make toxic soil, or directly use the granule preparation evenly skimmed under the trunk
The ground, and the medicinal soil is mixed with the soil with a rake and leveled. Use poison mantis, octyl thion, etc. to spray the source of the overwintering adult insects on the ground, and put the loose surface on the ground.
(2) Pharmaceutical treatment. It can be sprayed with 0.5% methyl vitamin salt microemulsion 1500-300 times, or 35% chlorobenzylamide water dispersible granules 7000-10000 times, or 20% cyanopyropentone at the first incubation larval stage. Marathon emulsion 1000 ~ 150 times for spray treatment, can also be used to kill mantis, cyanopyrrhea vinegar, avermectin, methyl salt, the first
Phenyl wormamide, juvenile extermination and other agents have a good effect on eggs and hatching larvae. In the defruiting stage of larvae, spray 40% to kill mantis microemulsion 1500 to 2000 times, or 3% avermectin microemulsion 3000-6000 times, or 14% chlorine worm perchlorine fluorophoride 3000 to 500 times spray treatment to poison and kill old mature larvae. It can also be used to control mature larvae by using permethrin, high-efficiency permethrin, cypermethrin, and juvenile clothing. Spray again 7 to 10 days after the initial spray, and good control effects can be achieved.
(3) Booby traps. In mid-May, the hanging core is suspended, which has the effect of monitoring and trapping peach heartworms.
Biological control
(1) Use parasitic wasps to carry out prevention and control. There are many types of peach heartworm parasitic bees, especially peach small early belly cocoon bees and Chinese tooth leg ji bees with higher parasitic rates and better effects.
(2) Insect pathogen nematodes. As a new biocontrol factor for agricultural and forestry pests, some strains of insect pathogen nematodes show good infestation activity against peach small heartworms. The results showed that the optimal concentration of S.feia 9 strain insect pathogen nematodes on peach heartworm larvae, summer cocoons and winter cocoons was 12,000 strips/mL. Some pesticides such as nematodes can be combined with nematodes, combined with drip irrigation, sprinkler irrigation, sprinkling, pouring and other application methods, to control peach small heartworms, can achieve good results,
(3) Biopesticides. Spray treatment is carried out with 80U/up Bacillus thuringensis 500 ~ 100 times liquid, and the effect is better. It can also be sprayed uniformly under the recommended dose of white zombie bacteria and green zombie bacteria agents, and can be applied to orchards with high requirements such as green and organic to carry out prevention and control.