What if you get the vegetable borer when you plant rape?

Rape, also known as rape, sowthistle, Latin name: Brassica campestris L. Cruciferae, Brassica plants, native to China, its stem color dark green, such as cabbage, is a variety of cruciferous cabbage, flowers are yellow. In agronomy, a number of species with oily seeds in plants are collectively referred to as rape. At present, the main cultivation types of rapeseed are Brassica napus (Brassica rapa (campestris) L.), mustard (Brassica juncea L.) and Brassica napus (Brassica napus L.).

What if you get the vegetable borer when you plant rape?

First of all, let's learn about rape borer.

Hellula undalis Fabricius Lepidoptera, Pyralidae. Alias cabbage borer, radish borer, cabbage borer, vegetable gouge wild borer, heart-eating beetle, heart-eating beetle, heart-eating worm. Synonym Phalaena undalis, Oeobiaundalis Fabricius. It is distributed from Heilongjiang and Inner Mongolia in the north to the border in the south. The South has been badly hurt. In recent years, Hebei, Shandong and Henan have also done more harm.

The larva is a boring pest, which harms the heart leaves and leaves of vegetable seedlings, and the injured seedlings stop growing or wilt and die due to the destruction of the growing point, resulting in lack of seedlings and broken ridges. Cabbage, cabbage can not be affected by the ball, heart, and can spread soft rot, resulting in a reduction in yield.

The adult has a long 7mm, wingspan 15mm, grayish brown, with three white transverse ripples on the front wing, a dark brown kidney-shaped spot in the middle and a white edge on the middle, and a gray-white hind wing. The egg is about 0.3mm, oval, flat, with irregular reticulation on the surface, light yellow in the first birth, red spots later, and orange before hatching. The mature larvae have 12-14mm body length, black head, light yellow carcass, yellowish brown forechest dorsal plate, inconspicuous grayish brown longitudinal lines on the back, hairy tumors in each node, 6 pairs in the middle and back chest, 8 in the front row and 2 in the back row of each abdominal segment. The pupal body is about 7mm, yellowish brown, the wing bud reaches the posterior edge of the fourth ventral segment, 5 longitudinal lines on the back of the abdomen are faintly visible, 2 pairs of thorns grow at the end of the abdomen, 1 pair in the center is slightly shorter, and the end is slightly curved.

There are 3-4 generations a year in Beijing and Shandong, 6-7 generations in Shanghai and Chengdu, and 9 generations in Liuzhou, Guangxi. the silk sac is made of old mature larvae spinning soil grains on the ground and withered leaves (a few overwintering as pupae). In the next spring, the overwintering larvae were buried in 6-l0cm to make cocoon pupation. The phototaxis of adults is not strong, the flying ability is weak, and most of the eggs are scattered on the tender leaves of vegetable seedlings, with an average of about 200 eggs per female. The egg development period is 2-5 days. The latent leaves of the newly hatched larvae are harmful, the tunnel is wide and short; after the 2nd instar, they penetrate the leaves; the 3rd instar spit silk to decorate the heart leaves and feed inside, so that the heart leaves die and can no longer pull out the heart leaves; the 4th-5th instar can be eaten into the stem pulp or root by the heart leaves or petioles with significant wormholes with filaments and moist insect droppings. The injured seedlings withered or the petiole rotted. The larvae can be transformed into 4-5 plants. The 5th instar larva matured and pupated in the soil near the root of cabbage. From May to September, the development period of larva is 9-16 days and that of pupa is 4-19 days. This insect likes the environment of high temperature and low humidity. Autumn cabbage sown in Beijing from August to September has a temperature of about 24 ℃ and a relative humidity of about 67% during the period of 3-5 true leaves, which coincides with the peak period of larvae and suffers the most.

Control methods of rape borer, Chilo suppressalis

The main results are as follows: (1) Agricultural control is ploughing the land, which can eliminate some of the overwintering larvae in the topsoil or withered leaves and reduce the source of insects. The second is to adjust the sowing date so that the period of 3-5 true leaves of vegetable seedlings is staggered with that of Chilo suppressalis. Third, proper irrigation and increasing field humidity can not only inhibit pests, but also promote the growth of vegetable seedlings. (2) Chemical control of this pest is a boring pest, so spraying control must be carried out during the peak period of adults and the incubation period of larvae. It can be used to kill (21% synergistic cyanide horse EC) or 3000 times of fenvalerate EC, 2000 times of 2.5 kungfu EC, 20% thiazuron EC or 2.5% Uranus EC 3000 times, 20% chrysanthemum EC 2000-3000 times, 10% chrysanthemum horse EC 1500-2000 times. The effect is better.