Occurrence of fruit flies in stone fruit orchards and integrated control
Zhou Lei
In the past two years, the harm of fruit flies in stone fruit trees has shown an upward trend, especially large cherries, peaches and other heavy victims, which has become a threshold restricting their healthy development. Large cherries are the most harmful, with light early maturing varieties and late maturing varieties being heavy; Peaches, especially late-ripening peaches, are also harmful. The adults lay their eggs under the skin of the fruit, and after hatching, the larvae first pest under the skin of the fruit, and then moth to the heart of the fruit, and the flesh gradually becomes soft, brown, and slowly decaying. The rate of victim fruit commodities is reduced, becoming a secondary fruit, which seriously affects sales and efficiency, especially due to incomplete media reports, causing public consumption panic, causing a negative impact on the industry or even a blow, seriously affecting the healthy image of the industry, so it is necessary to strengthen the comprehensive prevention and control of fruit flies in order to solve the harm caused by fruit flies. [Yoshiyama Huayao self-media network debut]
1 Occurrence
1.1 Harmful characteristics
Fruit flies belong to the fruit fly family, is a saprophytic pest, the world's fruit fly family has found more than 2,000 species, widely present in the global temperate and tropical climate zone, because its staple food is yeast, most of the fruit flies feed on rotten fruits or plant bodies, a small number of only take fungi, sap or pollen for food. Among them, there are four main species of fruit flies that harm fruit trees, namely black-bellied fruit flies, Suzuki fruit flies (spot-winged fruit flies), Hyde's fruit flies and Imi fruit flies, of which the black-bellied fruit flies and Suzuki fruit flies are the main ones, accounting for 98% of the fruit flies. 56%。 Among them, the large cherries are mainly black-bellied fruit flies and Suzuki fruit flies, and the peaches are mainly Suzuki fruit flies. At present, early ripening peaches have not yet found fruit flies, and late ripening peaches such as gold and autumn tong have a heavier occurrence.
1.2 Morphological characteristics
(1) Drosophila black-bellied. Egg white, long 0. 5 mm, oblong-oval, flattened ventral surface, with 2 slender snorkels on the head. The larvae are maggot-like, with a slightly pointed tip at the tip, a pronounced black hook, and a generally white body color, which varies with the color of the juice consumed. Pupae are pupae, fusiform, 2 to 3 mm long, with 2 small breathing holes in the anterior segment, tail buds in the posterior part, and the pupae are milky white in the early stage and dark brown in the later stage. The male adult is small, with a blunt end of the abdomen, 4 ventral segments visible on the ventral surface of the abdomen, 3 distinct black stripes on the back of the abdomen, and 1 black comb on the first tarsal segment of the 2 forefoots. Female adult body length 2. 5 ～ 2. 6 mm , with a distinct 5 uninterrupted black stripes on the dorsal ventral back , a slightly pointed black caudal segment , a cylindrical ovipositor at the end , and a V-shaped arrangement on both sides with bristles. The ovipositor is not black serrated.
(2) Suzuki fruit fly. Egg white, long 0. 6 mm, oblong-oval, with 2 slender snorkels on the head, longer than those of Drosophila melanogaster. The larvae are cylindrical, milky white, pointed, and 3. 0 to 3.5 mm. Pupae are pupae, cylindrical, reddish-brown, 2 to 3 mm long, with 2 small breathing holes in the anterior segment and tail buds in the posterior part. Male adults grow 2. 6 to 2.8 mm, body color nearly yellowish brown or reddish brown, head with 1 pair of red compound eyes, thorax yellow-brown, 1 dark spot at the end of the 1st diameter of the wing vein, 3 to 6 personality combs at the 1st tarsal and 2nd tarsal segments of the forefoot. The hermaphroditic alien is obvious. Female adult body length 3. 2 ～ 3. 4 mm, the female has an uninterrupted black band on the back of the ventral segment, a black ring at the end of the abdomen, a dark spot at the apex of the anterior edge of the wing, a distinctly black serration on the ovipositor, 2 rows of serrations on the spawner, and a number of 30 to 36 serrations.
1.3 Occurrence
(1) Drosophila black-bellied. Occurs 10 to 11 generations in 1 year, with 11 more generations occurring, pupae overwintering in the soil under the tree 1 to 3 cm, rotten fruit or fruit husk. In mid-to-late March, adult insects begin to appear when the temperature is about 15 °C and the ground temperature is 5 °C, and when the temperature is stable at about 20 °C and the ground temperature is stable at about 15 °C, the adult worm reaches the peak of feathering, and the amount of insects increases. In mid-May, adults begin to lay eggs on large cherries and other fruits, late May to early June is the peak period of egg laying, larvae in the fruit generally after 5 to 6 days of old ripening and bite through the peel and fruit peel to pupate, pupa feathers into adults and continue to spawn and reproduce the next generation, there is a phenomenon of generational overlap. After the harvest of large cherry fruits, turn to mature apricots, plums, peaches and other ripe fruits or rotten fruits as a pest, in late September, with the temperature drop the number of adult insects decreased significantly, late October to early November, the old mature landing larvae in the soil or rotten fruit pupated overwintering.
(2) Suzuki fruit fly. Suzuki fruit fly, also known as spot-winged fruit fly, can occur 3 to 10 generations in 1 year, up to 13 generations, and complete the life history of 1 generation as soon as 12 days. The lifespan of adult insects varies greatly between different algebras in different seasons, and the length of life is mainly affected by temperature, and the adults live for 3 weeks to 10 months, mainly overwintering with adults, and sometimes with larvae and pupae. Spring temperature to about 10 °C adult insects began to move, each spawn 1 to 3, each adult produced nearly 400 eggs, eggs hatched into larvae for 12 to 72 hours at room temperature, the larvae ate in the fruit for 3 to 13 days, matured pupae, pupae after 1 to 5 days that feathered into adults. It usually overwinters in adult form, but can also overwinter in the form of larvae and pupae.
1.4 Differences in the hazards of Drosophila Black and Fruit Fly Suzuki
Black-bellied fruit fly is a carrivish, mostly eating rotten fruits, because there is no serrated egg layer, can only harm the fully ripe or rotten fruit, that is, only in the late stage of fruit ripening, Suzuki fruit fly has a greater impact on the commerciality of the fruit, it can start from the fruiting period. In addition to eating ground fruit or damaged fruit, because the female egg layer is hard and jagged, eggs can be laid directly in the softer peel of immature, near-ripe and fully ripe large cherries, peaches, plums and other fruits, and the larvae eat the pulp inside the fruit to cause harm, and the damaged fruit quickly decays around the feeding point, and causes secondary infestation of fungi, bacteria or other diseases, accelerating the decay of the fruit.
2 Integrated management of fruit flies
Although the eggs and larvae of fruit flies in the fruit are harmless to humans and animals, nor are they infectious and parasitic, they are extremely harmful due to generational overlap and rapid reproduction. Therefore, it is necessary to intensify prevention and control, implement the principle of "prevention first, comprehensive prevention and control" in production, and concentrate on contiguous orchards to require the implementation of the prevention and control strategy of mass prevention and control and unified prevention and control. Taking the fruit ripening period as the key period, taking the control of adult insects as the key insect state, early prevention and early control, focusing on cleaning the orchard, reducing the occurrence of fruit flies, trapping or smoking adult insects, and avoiding fruit damage, taking physical + biological + chemical methods of integrated control to reduce the occurrence and degree of harm of fruit flies.
2.1 Clean the orchard and lower the insect population base
In mid-to-late March, spray orchard floors and weeds with 40% octylthion emulsion 1500x solution or 40% Lesben emulsion 1500x liquid to lower the drosophila base.
During the fruit coloring period, timely clean up the weeds and garbage in the orchard, timely pick up, remove and remove the falling fruit, rotten fruit, diseased and insect fruit, split fruit and residual fruit in the orchard, and reduce the food source and population breeding site of fruit flies. After harvesting, it is necessary to completely remove the borer fruit and mildew fruit on the tree and under the tree and carry out drug treatment, and then bury it deeply, if necessary, it can be used to use high-efficiency and low-toxic agents for ground spray treatment, and remove the breeding place of fruit flies in the orchard to achieve the purpose of effectively reducing the number of fruit flies.
In late autumn and early winter, the deep ploughing of the garden is generally carried out in combination with the application of basal fertilizer from late October to before the soil freezes, with a depth of 20 to 25 cm, to eliminate the drosophila pupae that overwinter in the soil.
2. 2 Timely harvesting to reduce the chance of borers
Reasonable matching of varieties, the choice of tight skin, thick flesh, high gloss varieties, so that timely harvesting, ripe batch harvest, to avoid excessive ripening of the fruit, reduce the black-bellied fruit fly and other eggs in the fruit, reduce the harm.
2. 3 Improve ventilation and light transmission conditions, promote healthy body cultivation to strengthen orchard management, promote new models of cultivation methods such as trunk shape and "Y" shape, improve orchard ventilation and light transmission conditions through wide dense planting and simplified pruning, implement organic fertilizer substitution technology, increase organic fertilizer application, apply formula fertilization and water and fertilizer integration technology, balance nutrient supply, enhance tree potential, promote the healthy growth of fruits and trees, improve tree resistance, and reduce the occurrence of diseases and insect pests.
2. 4 Strengthen physical control, trap adult insects by using fruit fly bait or sweet and sour liquid, sticky worm board, plant tobacco agent and other ways to trap (kill) and avoid adult fruit fly; At the same time, the orchard mulching is implemented to isolate the fruit fly larvae from entering the soil to pupate and the feathering of adult insects, which is convenient for cleaning up the rotten fruits of diseases and insects.
Fruit fly bait is generally used 7 days before fruit picking, hanging 10 to 12 lure bags per acre, if the garden is relatively closed can hang about 20, the distance of adjacent lure bags is not more than 10 meters, most of them are hung on the branches at 2/3 of the height of the tree, and a small amount is hung 20 to 30 cm from the ground. After use, in case of high temperature and drought weather, it is necessary to supplement the enticing as appropriate, and orchards with a harvest period of more than 20 days need to replenish the enticing in time 15 to 18 days after use.
The sweet and sour liquid trap is hung in the shade of the lower part of the orchard canopy when the fruit begins to be colored, 40 to 80 cm above the ground, and 15 to 20 pots per acre. Ratio of sweet and sour liquid: Brown sugar, fruit wine, vinegar and water are mixed according to the ratio of 1 : 3 : 1 : 10, while adding a small amount of 90% crystal enemy insects or fly killers, the appropriate amount of juice can improve the booby trap effect, regularly remove adult worms in the basin, replace the sweet and sour solution once a week, when the amount of insects is large or when there is a lot of rain, the sweet and sour solution should be replaced or supplemented in time.
In addition, 30 to 50 yellow armyworm boards are hung per acre of orchard, which can effectively kill male insects, interfere with male and female mating, and reduce the insect population base.
Fruit bagging can effectively prevent adult insects from laying eggs, especially pay attention to bagging can be appropriately advanced, requiring timely bagging before the fruit is not laid by fruit flies at the young fruit stage, and spraying insecticides and fungicides before bagging within 1 to 3 days after bagging.
2. 5 Timely medication, three-dimensional prevention and treatment
Take a combination of under the tree and on the tree, and spray high-efficiency, low-toxic agents in time to kill adult insects. After the fruit begins to color under the tree, the ground is sprayed with 20% fly-killing amine soluble powder 800 times liquid, 2. 5% high-efficiency cypermethrin emulsion 2000~4000 times liquid, 40% chlorpyrifos emulsion 1500 times liquid, 2% avermectin emulsion 2000 times liquid and other agents, sprayed once every 7 to 10 days, sprayed 2 to 3 times continuously.
It can also be used before the fruit coloring period begins to ripen, with a high efficiency cypermethrin ratio of about 1 : 5 or after mixing with water or 1. 82% amylmethrin smoking agent is mixed with water at 1 :1, and the ground is sprayed with smoke downwind with a smoke blower to kill adult insects.
On trees, generally before fruit harvest (generally outside the 15-day interval of pesticides), it is found that the population density of fruit flies in orchards is large and there is a harm to the tree, and the tree is sprayed in time 0. 6% bitter lactone aqueous 1000 times liquid, spray liquid added to the prepared 3% sweet and sour solution. Also can spray 1. 5% pyrethroid water emulsion 1000 ~ 1500 times liquid, 2. 5% rotenone emulsion 1200 ~ 2000 times liquid, 1% methylamino avermectin benzoate water dispersible granules 3000 times liquid, 1% avermectin emulsion 3000 times liquid, 60 g / L ethyl polybactericide suspension 2000 times liquid, 4. 5% high-efficiency cyfcypermethrin emulsion 1500 times liquid and other high-efficiency low-toxicity low-residue insecticides, pay attention to the spraying of the canopy inner chamber part. After fruit harvesting, the tree body and the weeds on the ground and surrounding weeds in the park are sprayed with insecticide once in time.