Control of Chilo suppressalis in Yellow Poplar

Lepidoptera: Pyralidae is one of the leaf-eating pests on hedge plants such as Populus tomentosa, Populus tomentosa and so on. It is mainly harmful to the top tips and leaves of hedge plants, resulting in bare branches and leaves, which greatly reduces the greening and ornamental value. In recent years, the harm has been aggravated year by year in all parts of the country.

Distribution and damage are distributed in Sichuan, Guizhou, Hubei, Hunan, Guangdong, Fujian, Jiangxi, Zhejiang, Shanghai, Jiangsu, Shandong, Hebei, Shaanxi, Qinghai, Xizang. The larvae spit silk to decorate the leaves and nest and feed on the leaves and tender shoots, especially to harm the young leaves of the new shoots and affect the growth of the trees. in serious cases, the whole leaves are eaten up, and only silk mesh, residual leaves and fragments are left on the crown, coupled with the slow growth and poor regeneration ability of boxwood. Often wither and die.

Morphological characteristics

1. Adults: body length 14 mm to 19 mm, wingspan 33 mm to 45 mm; head dark brown, scaly hairs between top antennae white, antennae brown; light brown chest and abdomen, brown scales on chest, dark brown at the end of abdomen The wing is white and translucent, with purple flash, the front edge of the wing is brown, there are two white spots in the middle chamber, one is small, the other is curved into a crescent shape, there is a brown band on the outer edge and the posterior edge, and the outer edge of the hind wing is dark brown.

2. Eggs: oval, 0.8 mm to 1.2 mm long, white to milky white at birth and light brown before hatching.

3. Larvae: mature body length 42 mm to 60 mm, head width 3.7 mm to 4.5 mm; milky white at first hatching, dark brown before pupation, carcass yellowish green, glossy hairy tumor and sparse burr on the surface, large black spots on the back of the forechest, triangles, two pieces; topline green, subtopline and upper valve line dark brown, valve line yellowish green, baseline and ventral line light bluish gray The chest foot is dark yellow and the abdomen foot is yellowish green.

4. Pupa: fusiform, brown, 24 mm to 26 mm long and 6 mm to 8 mm wide; 6 gluteal thorns at the tail end of the abdomen, cocoon formed by silk leaves, cocoon length 25 mm to 27 mm.

The occurrence regularity occurred three generations a year in Shandong area, and the third generation of low-instar larvae overwintered as cocoons in the leaf bud, and the damage began in the middle of April of the following year, then pupation and Eclosion began, and adults were not seen until early May. The adults mostly Eclosion in the evening, mate the next day, and lay eggs on the second day after mating. The eggs are mostly laid on the back of leaves or branches, and a few are scattered, with 3 to 13 eggs per egg block and 123 to 219 eggs per female adult. Adults sleep during the day and go out at night, often live in shade during the day, fly away quickly when disturbed, mate and lay eggs at night, and have phototaxis. After hatching, the larvae are scattered to look for tender leaves to feed, and the newly hatched larvae feed on the back of the leaves. The 2nd to 3rd instar larvae spun silk to connect the leaves and twigs to form a nest, feeding on the leaves inside, showing a notched shape. After the 3rd instar, the feeding range expanded, the food intake increased, and the damage was aggravated. The severely damaged plants only had residual screen, insect skin, insect dung, and a small amount of residual leaf edge and leaf edge. Transfer the damage after 4 years old, hide in the nest immediately when you encounter alarm, and pupa the leaves after ripening.

Prevention and cure measures

1. Removing withered branches and rolling leaves in winter and centrally destroying overwintering cocoons can effectively reduce the source of insects in the second year.

2. By making use of its nesting habits, the insect nests were removed in time in the early stage of the first generation, and the cocoons were removed and destroyed in the pupation stage, which could reduce the occurrence of insect pests in the same year.

3. Make use of the phototaxis of adults, set up black light or frequency vibrating insecticidal lamps to trap and kill adults.

4. Chemical control: the key period of control is the dormant stage of overwintering larvae and the low instar stage of the first generation larvae. 2000 times of methamphetamine EC, 2000 times of 2.5% Kungfu EC and 2000 times of 2.5% enemy-killing EC can be used. Some low-toxic, non-polluting pesticides and biological pesticides, such as avermectin, B.T emulsion, etc.

5. Protection and utilization of natural enemies: protection and utilization of natural enemies such as parasitic concave wasps, jumping wasps, Beauveria bassiana and parasitic flies, or artificial breeding and release in concentrated areas can effectively control their damage.