Is the cabbage worm poisonous? What is its natural enemy? What are the occurrence and prevention methods?

Pieris rapae, also known as Pieris rapae, and its larvae, also known as Pieris rapae, are the most common, most harmful and often harmful pests in China. So is the cabbage worm poisonous? What is its natural enemy? What are the occurrence and prevention methods? According to the data of Pteropteridae, cabbage worm is non-toxic, and it is addicted to cruciferous plants, especially cabbage, cauliflower, cabbage and radish with thick leaves.

What are the natural enemies of cabbage insects?

1. At present, it is known that the predatory natural enemies of Pieris rapae in egg stage are flower bug, green-winged ant-shaped cryptopterus, Chinese micro-thorn bug and so on, and the predatory natural enemies in larva and pupa stage are assassin bug, wasp and spider.

two。 Seven species of spiders, such as jumping spider, eight-spotted ventral spider, small black spider, and two kinds of natural enemies, such as discolored ladybug and tortoise lady beetle, have great potential to control the eggs and larvae of Pieris rapae. The natural enemy with the highest correlation with the eggs of Pieris rapae is the tortoise ladybug, and the natural enemy with the highest correlation with Pieris rapae is the Chinese jumping spider.

What are the occurrence and control methods of cabbage insect?

Pieris rapae belongs to Lepidoptera Pteropteridae, which is a common pest of vegetable crops. Its adults are called Pieris rapae, Pieris rapae or Pieris rapae, which can reproduce 8 mi 9 generations a year. The generation overlap is serious, and the adults are active during the day and inhabit at night. The larvae could be harmed by transplant and had pseudo-death, which occurred from April to June and from August to September. Pieris rapae is partial to cruciferous vegetables, which prefer cabbage, broccoli, cabbage and radish; it can also harm lettuce, amaranth and other plants; the temperature range for its growth and development is 10: 34 ℃, the optimum temperature is 20: 25 ℃, and the relative humidity is 70% 90%. Strengthen the dynamic monitoring of the occurrence of cabbage pests in vegetables, and timely release disease and pest forecasts, timely carry out classification guidance, effectively control the harm of diseases and insect pests, and ensure the safety of vegetable production.

In recent years, the occurrence of Pieris rapae is serious, and drug resistance occurs rapidly in the process of chemical control, resulting in difficulties in the control of Pieris rapae. The key points of its prevention and control are timely prevention and treatment and alternative use of drugs, and the specific prevention and control methods are as follows:

1. Clean the countryside, deal with residual plants, old leaves and weeds in time after harvest, and reduce the source of insects. Deep ploughing fine rake to reduce the source of overwintering insects. Rotation with eggplant fruit vegetables and onion garlic vegetables or food crops to reduce the number of insect population.

two。 Rotation with eggplant fruit vegetables and onion garlic vegetables or food crops to reduce the number of insect population.

3. Due to the serious generation overlap of Pieris rapae, the food intake and drug resistance of the larvae increased after the 3rd instar. Therefore, the pesticide should be used 3 times continuously before the 2nd instar, and the following agents can be selected: ① 2% vegetable Dan insecticide 30 Murray 50 g / mu, spray 50 kg of water or 0.2% Avermectin EC 2500 Mel 3000 times. These two pesticides are biological insecticides with good effect, not easy to produce drug resistance, no pollution, and can be used continuously. ② 10ml / mu, 10ml / mu, 5ml / mu, 10ml / mu, 10ml /