Control time of rice stem borer

Rice borer drills into the rice stalk to feed through the larvae, which poses a great threat to rice. When is the control time of rice borer?

1. Control time of rice borer

The control time of rice borer should be determined according to the situation of pest and seedling, and the drug control should be done from the peak of egg hatching to the occurrence of the first instar larvae, and the specific time is based on the information of the local plant protection station.

2. Characteristics of rice borer

1. Chilo suppressalis

Chilo suppressalis is distributed in all rice areas in China, and it is more serious in the south of the Yangtze River. Its hosts are rice, wheat, corn, Zizania caduciflora, broad bean, rape and so on.

The larvae of Chilo suppressalis are stout when they are mature, with a length of 20mm and 30mm, reddish brown head and purplish red on the back of the body.

The adult's body is 12-15 mm long, the wing is 27-30 mm wide, the body is hypertrophic, and the female moth's body is larger. The head and chest is grayish brown, the abdomen is light brown, the forewings are nearly rectangular, light grayish brown, the outer edge is dark, and there is a dark brown line from the wing base to the outer edge.

The pupa of Chilo suppressalis is relatively hypertrophic, yellowish brown, 13-18 mm long, with powdery secretions on the head and chest.

The eggs of Chilo suppressalis are oval, brown, with longitudinal and horizontal lines on the surface, and the eggs are mostly laid in the leaf sheath, usually with 2-3 rows and more than a dozen grains gathered together.

2. Chilo suppressalis

Chilo suppressalis is widely distributed, ranging from Heilongjiang in the north to Hainan Island in the south, and is common in the north and south of China. It can harm not only rice, but also Zizania caduciflora, corn, broad bean, rape and so on.

The mature larvae of Chilo suppressalis are larger, with a body length of 20mm and 30mm, a reddish brown head and a light brown body, with five brown stripes on the back.

The adult is 10-15 mm long and grayish brown. The front wing of the female moth is nearly rectangular and there are 7 small black spots on the outer edge. Male moths are slightly smaller than females, and their body color and wing color are darker.

The pupa of Chilo suppressalis is 11-17 mm long, cylindrical and brown. Five dark brown vertical lines can be seen on the back of the early stage.

The eggs of Chilo suppressalis are flat and oval, about 1.2 mm long, and are glued together by dozens or even hundreds of eggs.

3. Chilo suppressalis

Chilo suppressalis is mainly distributed in the Yangtze River basin and its southern rice area, from the north sporadic to Yantai.

The larva of Chilo suppressalis, 14-20 mm long, yellowish white, head yellowish brown or light brown.

The adult of Chilo suppressalis is 8-13 mm long with triangular forewings, and the female is relatively large and yellowish all over. There is an obvious small black spot in the center of the two forewings and a bunch of yellowish-brown villi at the end of the abdomen. The male is relatively small, the whole body is grayish brown, there is also an obvious small black spot in the center of the forewing, and there is a dark brown twill from the tip of the wing to the center of the wing.

The pupa of Chilo suppressalis is in the shape of a long cylinder, green and white, and the pupa to be Eclosion is brown. The pupa is 10-15 mm long.

The eggs of Chilo suppressalis are oblong, waxy and lumpy, each with dozens or even hundreds of eggs, covered with yellowish-brown villi.

The rice stem borer (Chilo suppressalis) eats rice exclusively. The harm of Chilo suppressalis larvae can be found throughout the whole growth period of rice. It is easy to cause withered seedlings at seedling stage and tillering stage, dead booting at booting stage and white panicle at heading stage.

III. Control of rice borer

The main results are as follows: 1. In the cultivation system, the coexistence of single-cropping and double-cropping rice is changed into large-scale double-cropping rice or single-cropping rice, and the "bridge field" which is beneficial to the survival of borers is eliminated as far as possible. Transplanting seedlings at the right time and reasonable management can make the peak period of borer stagger with the tillering stage and booting stage of rice.

2. Root out the weeds on the edge of the field during winter and spring, and destroy the overwintering larvae and pupae. Eliminate barnyardgrass and field edge weeds before the eggs are fully hatched.

3. The pupation period of the borer is generally in the spring ploughing season, when spring ploughing and retting is necessary. Rice stakes, straw and weeds are turned into the soil to eliminate overwintering larvae and reduce the base number of pests.

4. At the same time, physical control methods are used to kill or hinder pests by means of light, high temperature or obstacles. The more mature physical control method applied in production is to trap and kill adults by light. The adults of rice borer have a strong tendency to the light emitted by black light and frequency vibration insecticidal lamp. in the peak period of adults, using black light or frequency vibration insecticidal lamp can trap and kill a large number of adults, thus reducing the amount of eggs laid by adults. can play a good preventive effect.

5. Chemical control. According to the different characteristics of Chilo suppressalis, Chilo suppressalis and Chilo suppressalis, different pesticides were selected for control.

Control Chilo suppressalis, when the symptoms of withered seedlings are found in the seedling stage, it should be sprayed in time. 18% insecticidal double water agent can be used with 200ml per mu and spray 50kg of water. Spray once every 5-7 days, generally prevent and cure it for 2-3 times. At the jointing stage of rice, 40% imidacloprid was used to spray 50 kg of water. From booting stage to heading stage, the ideal control effect can be achieved by spraying 50 kg water with 200ml / mu of insecticidal double water agent.

To control Chilo suppressalis, when it is found that Chilo suppressalis harms seedlings and causes withered seedlings at seedling stage, 25% Shachongshuang 100g / mu can be used to control water 50kg / mu, and 100kg 150g / mu 50% dimethoate EC is sprayed on water 50kg / mu at white panicle stage, which has a good insecticidal and egg killing effect.

For Chilo suppressalis, the withered seedlings and white ears can be effectively prevented by spraying 50 kg of water with 5% fipronil 15ml / mu during the peak egg incubation period and the broken ear stage.

The hatching of rice borer is relatively fast, and there are differences in different generations, and it will also be affected by region and temperature. therefore, it is best to consult the relevant departments in the time of control.