How to fight and spray cherries against worms

The cherry fruit fly is one of the main pests of cherry orchards. They damage the fruit through feeding as adults and larvae, and during egg laying. The larvae, which develop within the fruit itself, are of greatest concern. It is very difficult to determine whether worms are present in cherries and how to control them, as the fly eggs and the puncture wound left by the fruit fly are very small and difficult to detect. Damage to cherries often appears as a spot during ripening.

Life cycle of the cherry fly

This is a small insect with a bright black thorax, a yellow scutellum, and a distinctive wing pattern. It ranges in size from 4 mm (males) to 5 mm (females). It doesn't fly very far, typically reaching a range of 50 to 100 m. This insect produces one generation each year, going through several stages. The first stage is emergence and mating. Adult flies emerge when the days warm up and the soil reaches 10°C.

For 10-14 days, they feed on aphids, dew on berries and leaves, cherries, and their juice. Once satiated, the fly begins preparing for reproduction by laying eggs. Egg-laying occurs around midday and early afternoon, in sunny, warm weather, when the temperature rises above 16°C. Weather conditions during the egg-laying period are considered crucial for regulating population density: high egg-laying activity during prolonged periods of good weather can lead to extreme outbreaks of this pest. Females emerge first, followed by males. After laying eggs, the insect dies.

The next stage is larval development. Seven days after the eggs are laid, a small white worm, approximately 5 mm long, emerges. The larva feeds on the cherry pulp, moving toward the pit. The berry rots and falls off, taking the worm with it. This stage lasts 2-3 weeks. After this stage, the worm, now 6 to 8 mm long, emerges from the berry. Within a few hours, it burrows into the soil to pupate.

The final stage is the pupa. This stage most often occurs in early June. The pupa is straw-yellow in color, cylindrical, up to 4 mm long and 2 mm in diameter. The depth of pupation depends primarily on soil type and typically ranges from 1 to 13 cm. Overwintering pupae enter diapause and require a period of cooling before development continues. Mortality of pupae during the 9-10 months of diapause is high and is mainly due to unfavorable climatic conditions and predation: often, only 5-15% of pupae emerge the following season.

Damage caused and consequences of use

Control measures target the adult fly, because once the eggs are laid, the damage is already done. The insect damages all cherry varieties. However, worms are rarely found on early-ripening varieties; the females simply don't have time to lay eggs. The worm-infested berries become softer, rot, and fall off. These pests can destroy an entire crop. Berries with larvae inside them shrink, become deformed, and decrease in size. The later a cherry variety is harvested, the higher the risk of infestation.

These berries are used to make jams or compotes. However, before doing so, they must be cleaned of any harmful insects. You can get rid of worms in cherries by soaking them in water and salt. This procedure is particularly useful before making jam or compote. The recipe for the solution is simple: take a large container, fill it with water, and dissolve a few tablespoons of salt in it. Stir the solution and pour it over the worm-infested cherries. After 2-3 hours, the larvae will emerge and float to the surface.

There's nothing wrong with eating wormy cherries. People often eat them without checking the inside. Those who do check throw away the wormy berries. The larvae don't harm people who accidentally swallow them, as they're not adapted to life in the human intestine and consist primarily of cherry pulp. But the very thought of eating a worm is repulsive.

Preventive measures and folk methods of control

Covering the soil under the tree canopy with netting to prevent cherry blossom flies from reaching the fruit is another effective control strategy. Since the flies can survive for long periods under the netting, the edges of the netting are completely buried. Fine mesh (0.8 mm mesh width) is used, as young flies easily pass through mesh with a 1.3 mm mesh width upon emergence.

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Liquid traps with food bait. These are used when temperatures rise above freezing. Various drinks are poured into open containers:

• compote;
• kvass;
• beer;
• aqueous solution of honey.

These "treats" are hung in the shade of cherry trees. The scent of the sweet liquid attracts cherry flies. The bait in the trap is refreshed weekly.

https://youtu.be/c4eKYzoZz28

Since pupae spend approximately 10 months a year in the soil, and the pupation area is strictly limited to the surface directly under the canopy of infested trees, digging the soil to bury the pupae deeper is the simplest method of control. Digging depth is 30-50 cm. Once the stone fruit harvest is complete, all fallen cherries are collected from under the trees. They are either removed completely or buried (50 cm) to prevent the larvae from pupating. Such conditions are unfavorable for the trapped larvae, which die. Eliminating aphids will eliminate problems with the cherry fruit fly, forcing them to migrate in search of food. The problem with this dangerous pest is partially solved by early and complete harvesting of the cherries—preferably, without any fruit remaining on the branches.

There are many different folk methods for controlling the fly, which have been used since time immemorial. These include traditional decoctions sprayed on cherry trees. For example, decoctions of wormwood, tobacco, and garlic and onion solutions. Spraying the cherry trees with a concentrated soap solution creates a film on them that the pest dislikes. This is safe for the trees themselves. At the same time, these solutions target cherry aphid control, which the fly feeds on. It will be completely destroyed, and the flies will be fewer in the treated area. A pine branch is a good ingredient for a chemical-free solution. Place the branch in a pot of water and boil. Leave it in a dark place for 24 hours. Spraying with this infusion is safe and effective.

Chemical treatment: when and what to spray

Chemical treatments are used only in extreme cases, when other treatments or methods other than spraying have proven ineffective. Cherry trees can be treated with any insecticide; commonly used products include Iskra, Aktara, Karate, or Fufanon.

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Iskra is a versatile and fast-acting product. Its action is enhanced by the addition of a second active ingredient. It contains potassium fertilizer, which accelerates the recovery of damaged areas. Currently, it is the only second-action insecticide. Its advantage is its low cost combined with high effectiveness. It dissolves quickly in water.

Aktar is available as a powder. To prepare a solution, it is diluted with water. It is applied in two ways: by spraying and by watering at the roots. The latter method, thanks to its systemic action, protects against both soil and ground insects.

Karate is used to rid trees of aphids. The working solution is prepared in two stages. The contents of the ampoule are diluted with a small amount of water and stirred until smooth, then water is added to achieve the desired concentration.

The tree itself and the surrounding ground are sprayed when flies emerge en masse. If the trees are treated with chemical-free products, repeat the treatment after rainfall. After flowering, apply Bordeaux mixture (0.1%). If there are clear signs of infection, add Topaz or Chorus to the solution. Early-ripening cherry trees are planted away from late- and mid-season varieties to prevent them from being contaminated with the chemical.

When worms are detected in cherry trees, they consider how to get rid of them and what control measures are best at the moment. A comprehensive approach of preventative measures, including biological treatments, is recommended initially. Since the eggs are laid under the skin and the larvae feed inside the berries, insecticides are ineffective. Therefore, it is necessary to combat the fly itself.