Mechanical methods of pest control in greenhouses and vegetable gardens

Mechanical methods of pest control in greenhouses and garden beds are an environmentally safe foundation for a healthy harvest. They not only protect plants here and now, but also preserve the biological balance of the soil for the future. Regular inspection of the undersides of leaves, destruction of egg clutches, and manual collection of caterpillars allow for the control of pest populations without the use of chemicals.

How to clean the soil of wireworms and mole crickets

Wireworms are tough, yellow larvae of click beetles that live in the soil for several years before pupation. They damage the underground parts of all garden crops, especially in uncultivated areas overgrown with couch grass. To reduce their numbers before sowing or planting, potato baits are used.

• Wireworm larva length — 1–2.5 cm
• Lifespan in soil — 3–4 years
• Pupation time for larvae — 2–3 weeks
• Bait placement depth — 15 cm
• Time for setup before sowing — 3–4 days
• Bait application rate per meter of bed — 2–4 pcs.

To trap them, potato wedges with small sticks inserted are buried in the soil. The protruding sticks help to quickly find and extract the traps along with the pests. If soil infestation is high, the procedure is repeated after sowing seeds or planting transplants.

The mole cricket is a dangerous, large pest that eats the underground parts of almost all crops. Its natural habitat includes moist soils with a high water table and a high humus content. The insect enters other soil types primarily through human activity.

In infested plots, mole crickets are caught in jars buried at ground level and filled with liquid. In spring, they are placed in the edges of the beds, as these warm up faster than the center. Placing traps in the center of the beds is impractical, as it hinders irrigation and the application of top dressing.

For mass destruction of mole crickets in autumn, thermal traps are organized in piles of manure. Pests eagerly gather in them for hibernation, attracted by the warmth and moisture. This allows for the destruction of the entire population once steady frosts set in.

1. In late September or early October, lay out a large pile of horse manure on the plot.
2. Insulate the pile with straw or another breathable material.
3. When the air temperature drops to -20 °C or lower, scatter the manure across the plot so that the pests freeze.

Protection against slugs and specialized flies

Naked slugs damage the aerial and underground parts of cabbage, legume, and celery crops. Normally, their numbers are kept in check by natural enemies—hedgehogs, toads, and frogs. If these predators are eliminated on a plot, slugs quickly become a disaster, especially in low-lying and shaded areas.

In rainy years, control begins in May, when overwintered individuals become active and the young are born. Slugs are collected manually using evening trap covers, under which they hide during the day. Moisture-absorbent materials are used as these covers.

• Wet rags or damp soft burlap;
• Boards, pieces of plywood, large leaves of rhubarb, burdock, or cabbage;
• Rolled-up damp newspapers (which are collected and burned during the day);
• Saucers with beer or sweetened water.

During the day, the pests gathered under the covers are shaken into a bucket with a soap solution. Additionally, plants are protected with mechanical barriers. To do this, the outer edges of the beds are sprinkled with coarse sand, and the inner surface is mulched with spruce needles.

Vegetable flies represent a highly specialized threat. Carrot, onion, beet leaf miner, as well as spring and summer cabbage flies are dangerous to their respective crops. Seedcorn maggot larvae destroy swelling pea and cucurbit seeds during germination.

The most harmful of these is the spring cabbage fly, whose larvae attack cabbage, especially early white cabbage and cauliflower, as well as radish. The first generation of larvae poses the greatest danger, as they feed on the roots of young plants, damaging them from the outside and inside. The plants become wilted, take on a dull bluish tint, and most often die.

The second generation of larvae, which appear in mid-summer, feed on the roots of robust adult plants, and their presence usually has little effect on the state of the cabbage. Only transplants of cabbage crops planted in July can be severely affected by second-generation larvae and summer cabbage fly larvae.

To protect spring and summer transplants of cabbage crops from larvae, it is necessary to prevent the possibility of eggs appearing on the surface of the ridge. To do this, it is sufficient to block the flies' access to the soil by covering ridges of white cabbage and cauliflower, broccoli, kohlrabi, and, if necessary, radish ridges with a transparent cover material ("Spunbond", "Lutrasil", or "Agril"). The cover fabric must be pressed tightly against the soil so that there are no gaps, and it must not have any damage. Irrigation should be performed without removing the fabric, directly through it, and the fabric is lifted for a short time only for the application of top dressing. A microclimate favorable for cabbage crops is created under the fabric, and they grow quickly. The flight of the spring cabbage fly begins in mid-May, simultaneously with the start of birch and dandelion flowering, sometimes coinciding with the start of cherry flowering, and peaks during the flowering of lilac. All this time, the ridges with cabbage crops must be reliably covered. This will protect the plants not only from the spring cabbage fly but also from the cabbage butterfly, which flies in clear sunny weather throughout May.

Cruciferous (flea) beetles. These small beetles are most fond of the leaves of rutabaga, turnip, radish, radish, as well as young cabbage. If many beetles have gathered on the ridges, this indicates that the irrigation is insufficient and the application rate of irrigation water needs to be increased.

In hot, dry weather, which is favorable for the pest and unfavorable for the mentioned vegetable crops, the number of flea beetles can be reduced by catching them on sticky traps. A leg is attached to a small piece of plywood or cardboard so that it can be stuck into the ground. A sheet of cardboard painted yellow on both sides is smeared with non-drying glue, and this trap is placed between two rows of plants. If the flea beetles feeding on the leaves are disturbed by stirring the leaves, they will jump onto the sticky surface. Preparations that do not lose their adhesive properties for many months can be applied to the plywood. Once you have made a sticky trap, it can be used throughout the summer. Many insects, including whitefly, are attracted to the yellow color.

Garden moth. It causes significant damage to all nightshade crops — tomato, pepper, eggplant. After hatching from eggs in the spring, the green caterpillars settle on the underside of the leaf, eating through the tissue. In addition to leaves, they also damage green fruits. The moth butterfly appears in late May — early June. It lays up to 1000 eggs. The moth larva lives for 30–40 days, actively feeding on plant leaves. To control the caterpillars, plants are sprayed with carbophos and other preparations, the labels of which state that they are effective against this type of pest.

Spider mite. It causes great damage to cucumbers in greenhouses and under plastic covers. This sucking insect settles on the underside of the leaf, forming a sparse web. Light spots appear on the outer side of damaged leaves. With severe damage, the leaves discolor and die. The female lays up to 100 eggs per clutch. At a temperature of 28—30 °C, the mite becomes an adult within 8—10 days. It overwinters on plant residues, in the cracks of greenhouses and hotbeds.

Damaged plants, from the very beginning of the pest's appearance, are sprayed 1–2 times with "Keltan" at 20 g, carbophos at 60 g, or trichlorometaphos-3 at 50-100 g per 10 l of water, respectively, 20, 30, and 30 days before the start of harvesting.

The biological method of control is an effective means. For this, a natural enemy of the mite is used — the phytoseiulus. It is propagated on soybean plants and released onto plantings infested with spider mites, where it sucks out the eggs. Throughout the summer, it is released from 2 to 6 times every 10-12 days, 80—100 individuals per 1 mg. The use of the fungus Entomophthora adjarica, which destroys the mite completely, is also effective. Against the spider mite and aphids, an infusion of chopped potato tops is used. For this, 1.2 kg of fresh greens or 0.8 kg of dry vegetative mass is soaked for 3 hours in 10 l of warm water. If tops of tomato are used, then 400 g of the mass is boiled for 30 minutes in 10 l of water. The decoction is diluted with water until the initial volume is increased fivefold. To combat the mite, it is also recommended to maintain high air humidity in the greenhouse by spraying the plants with water more often.

You can set up traps for insects. Scents are used not only to attract insects but also to repel them by spraying plants with substances that emit these odors. These include so-called pheromones and attractants.

Pheromones are substances secreted by females of certain insect species to attract males. By making a trap and placing a container with pheromones inside it, you can destroy a huge number of pests.

Attractants are substances similar in their action to pheromones. Currently, it has been possible to isolate and synthesize them artificially.

Insects crawling on the ground can be collected using trenches dug in the soil. Tops remaining after harvesting harvesting">harvesting must be collected and burned to prevent the spread of diseases and pests.