Early Control of main Underground damage of Potato

I. main pests

1. Mole cricket is also called Lala Oratosquilla and country Dog son. The adults of mole cricket (fully winged) and nymphs (unwinged) are harmful to potatoes. It uses mouthparts and front claws (front feet) to tear the underground stems or roots of potatoes into disordered filaments, wilting or dying the aboveground parts, and sometimes biting buds so that the buds can not grow, resulting in lack of seedlings. It digs tunnels in the soil, separates the young roots from the soil, breathes air, causes water loss, affects the growth of seedlings, and even dies. It bites tubers in autumn to form holes or make them susceptible to rot bacteria.

The adults and nymphs of mole cricket move up and down with the change of soil temperature in the ground. Dive 1.2 to 1.6 meters while overwintering to build a hole to sleep. In spring, the ground temperature rises, and the plough layer is harmful to the depth of 10 centimeters. Move underground during the day and on the ground at night. When the temperature is high in summer, it is active at a depth of about 20 centimeters, and it is harmful to the plough layer in autumn. Generally speaking, the harm of mole cricket in the soil with more organic matter and light saline-alkali is rampant.

2. Grubs, also known as ground silkworms, are the larvae of beetles. After the tuber is drilled and eaten, it leads to quality loss or decay. Adults (beetles) also fly to the plant and bite the leaves.

Grubs and their adults can survive the winter and move vertically up and down in the soil. The adults overwintered below 40 cm and the larvae below 90 cm, and then rose to a tillage layer about 10 cm deep in spring. It likes organic matter and lives in mule and horse dung. Adults are active at night and hide in the soil during the day. The larvae have 3 pairs of chest feet, obese, milky white, often curled into a horseshoe-shaped, pseudo-dead.

3. The golden needle worm, also known as the iron filariasis, is the larva of the turtle. In order to harm the larvae, the buds, roots and underground stems are drilled in spring. Although the thicker roots or stems are rarely bitten off, the seedlings will wilt or die gradually. In autumn, the larvae drill into the tuber and form a pore in the potato meat, which reduces the quality of the tuber, and some even cause rot.

The adults and larvae of the golden needle worm can drill into the soil below 60 cm to survive the winter, leaving wormholes, and then rise from the wormhole to the ploughing layer in spring. When the soil temperature exceeds 17 ℃ in summer, it gradually moves downwards, and when the surface temperature decreases in autumn, it enters the plough layer again. The larvae are white when they first hatch and change color with the change of growth. they are shiny, hard, 2-3 cm long and slender.

4. The land tiger is also called the soil silkworm and the root cutter. The larvae are very harmful. The adult is a kind of nocturnal moth, which is divided into small land tiger and yellow land tiger and so on. The ground tiger mainly harms the seedlings of crops such as potatoes, biting off the seedlings close to the ground, killing the whole seedling, and often dragging the bitten seedlings into the wormhole. When the larvae are young, they also bite the tender leaves, resulting in gaps and holes in the leaves. It also bites tubers underground, making smaller holes than grubs.

The larva of the ground tiger is a yellowish brown, dark brown or dark brown flesh worm, usually 3 to 5 centimeters long. The small tigers like the shady and humid environment, and there is a large number of insects in the places with large field coverage, weeds and high soil moisture; the yellow tigers like the dry environment, do not have high humidity requirements, and are afraid of heat in summer. Their adults all have phototaxis and molasses.

II. Prevention and control methods

The above-mentioned underground pests are different, but they have something in common. They are all underground, so the prevention and control methods are generally the same.

1. Dig deep into the ground and rake deeply in autumn. Destroy their overwintering environment, freeze to death a large number of larvae, pupae and adults ready to overwintering, reduce the number of overwintering and reduce the harm of the next year.

2. Clean the countryside. Remove weeds and debris from fields, ridges, lands, fields and ditches, and take them out of the ground for treatment to reduce the number of larvae and eggs.

3. Trap and kill adults. Using molasses trap, black light, fresh horse dung pile, grass handle and so on, the adults with phototaxis, molasses and horse manure can be trapped and killed respectively, which can reduce the oviposition of adults and the number of larvae.

4. Chemical control. Use poisonous soil and granules: sow with 1% trichlorfon powder 3kg / mu, 10 kg fine soil, or 1.5 kg / mu carbofuran granules 1.5 kg / mu and big thunder, etc., spread along the ridge in the ditch to kill underground pests harmful to the seedling stage. Or when ploughing, the above pesticides are scattered on the roots of the seedlings to kill pests.

Root irrigation: with 40% phoxim 1500 × 2000 times solution, root irrigation at seedling stage, 50 × 100 ml per plant.

Use poison bait: the above pesticides can also be used for small area control, mixed with fried wheat bran, corn or bran to make poison bait and sprinkle it in the field at night.