Control methods of main insect pests in Chinese cabbage

The main pests of Chinese cabbage are aphids, Plutella xylostella, Pieris rapae, Chilo suppressalis and yellow striped jumping beetle. Effective control of these pests is a necessary guarantee for high yield of Chinese cabbage. How can we control these pests? Below, the editor of Guizhou Agricultural Network will introduce to you the prevention and control methods of these insect pests of green vegetables.

Aphids

1. Harm: there are two kinds of aphids that harm green vegetables: Rhopalosiphum aphid (turnip aphid) and peach aphid, which are the main pests of green vegetables. The adult and nymph of these two kinds of vegetable aphids sucked vegetable juice, which made the leaves curled and yellowed, the plants dwarfed, and could spread virus diseases. Rhopalosiphum cabbage aphids occur for 20 generations a year, overwintering as wingless aphids in or on the leaf back of the host. The winged and wingless aphids were produced from March to April of the following year, and turned to main damage among cruciferous vegetables throughout the year. But autumn is the most harmful. Peach aphids produce 30 generations a year, wingless aphids winter in the leaves or on the back of the leaves, hatch from March to April in the following year, and produce a large number of winged aphids to migrate in May. Until winter. Male aphids can produce more than 100 offspring in isolation. When the climate is suitable, 4Mel can lay eggs once in 5 days, and the damage is more serious in dry years.

2. Control methods: it can be sprayed with 1500 times of 40% dimethoate emulsion or 4.5% of 3000 times of cypermethrin or 1500 times of Kezhibao produced by Ruide in Shenzhen.

Plutella xylostella

1. Harm: Plutella xylostella larva, commonly known as "tip at both ends", is another major pest against cabbage. The first instar larvae sneaked into the tissues to eat the mesophyll, the second instar began to eat the mesophyll on the back of the leaves, and after the third instar, the leaves were eaten into holes or reticulation. Plutella xylostella produces 10 generations a year, and adults, pupae and larvae can survive the winter. When the weather turns warm, the adults begin to move, and most of the eggs are laid on the back of the leaves near the veins. The average number of eggs laid by a female moth can reach 300. Plutella xylostella is generally damaged from April to October, especially from April to May and August to September, and the damage is serious.

2. Control methods: it can be sprayed and killed with 800 times liquid of 90% crystal trichlorfon or 1500 times liquid of 25% Kemiling 2000 times.

Cabbage worm

1. Harm: the cabbage worm is also called the green worm, and the adult is the cabbage white butterfly, also called the cabbage pink butterfly. Take the larva as the harmful leaf, eat into holes or missing carvings, and in severe cases, the whole leaf is eaten up, leaving only petioles and veins. Pieris rapae produces 9 generations a year and overwinters as pupae in November. The first generation of adults began to occur in mid-March. Adults feed on nectar during the day and like to lay eggs on cabbage and cauliflower. Each female moth can lay 100 / 200 eggs, and the egg period is 3 / 100 / 200 for 8 days. The larvae have a total of five instars, and the food intake before the third instar is small, and the drug resistance is poor.

2. Control methods: chemical control is the same as Plutella xylostella.

Vegetable borer

1. Harm: the larvae of cabbage borer are commonly known as drillworms. The newly hatched larvae spin silk and form a net in the heart of the seedlings and feed on the heart leaves. After the third instar, they can also drill down from the heart leaves to feed on the stem pith to the root, resulting in root rot. The vegetable seedlings suffered the most when there were 4 leaves in 3Mel. The vegetable borer produces 6 mi 7 generations a year. The larvae spin silk in the soil and stick to the dead leaves of the soil to make their nests and survive the winter in the bag. In the following spring, cocoons and pupations were formed in the soil or on the remnants of fallen leaves on the ground. After Eclosion, the adults are active at night, and the eggs are scattered on the leaves, especially in the heart leaves. The larvae have the characteristics of turning to the main damage, and the old mature larvae pupate in the soil or soil near the vegetable root.

2. Control methods: remove weeds and residual leaves of withered plants in the field, and eliminate pupa cocoons. In the vegetable seedling stage, that is, before the larvae spin and agglomerate, spray with 90% crystal trichlorfon 800 times solution or 25% Chinese medicine Meiling 1500 times liquid 2000 times.

Yellow curved striped jumping beetle

1. Harm: yellow striped flea is commonly known as flea, larva is commonly known as white maggot, and it is also one of the main pests harmful to vegetables. The adults and larvae of the yellow striped beetle can produce damage, and the adults mainly feed on leaves, as well as tender stems, buds and pods. The larvae peel off the root bark or decay into the root bark or into the root to form a tunnel, causing the plant to wither. The yellow striped leapfrog beetle produces 5 murine 6 generations a year, overwintering with adults in soil gaps, on the opposite side of vegetable leaves and in remnants and weeds on the ground, and continue to feed when the temperature is warmer. Each overwintering female adult can lay about 600 eggs. After hatching, the larvae feed on the vegetable roots, and the mature larvae pupate at a depth of 3 mi 7 cm under the soil surface.

2. control methods: after autumn, the weeds and withered plants of residual leaves in the field were removed and the overwintering adults were eliminated. When weeds grow in early spring, they should also be cleared in time, so that overwintering adults have no proper food. When adults are found, they are immediately sprayed and killed with 800 times of 90% crystal trichlorfon or 25% of Zhong Ke Mei Ling 1500mi 2000 times. The larvae can be killed by spraying the above chemicals on the soil surface.