Harmful symptoms and control methods of pest thrips

Thrips file with adults and nymphs to suck the juice of the young tissues (shoots, leaves, flowers, fruits, etc.) of the plant, the young leaves and shoots harden and curl and wither, the plant grows slowly, and the internodes are shortened. Young fruits (such as eggplant, cucumber, watermelon, etc.) will harden after being killed, causing fruit drop in serious cases, seriously affecting yield and quality. Let's take a look at the prevention and control methods of thrips pests.

Harmful characteristics of thrips

The main results are as follows: 1. Leaf damage: after the young leaves are damaged, the leaves become thinner, gray-white or grayish-brown spots appear on both sides of the leaf midvein, the epidermis is gray-brown, deformed and curled, and the growth potential is weak, which is easy to be confused with the side polyphagous tarsal mite.

2. young fruit damage: the epidermis oil cell ruptured, gradually lost water and dried up, and the scar expanded with the expansion of the fruit, showing different shapes of cork silver-white or gray spots, but a few occurred in the waist and other parts of the fruit.

Agricultural control of thrips

1. Remove weeds and withered branches and leaves in the field in early spring, burn them or bury them deeply, and eliminate overwintering adults and nymphs.

2. Strengthen fertilizer and water management to promote plant growth and reduce damage.

3. Make use of the blue habit of thrips, set up blue sticky plates in the field to trap and kill adults, and the sticky plate height is the same as that of crops.

Chemical control of thrips

1. Rice: thiazine varieties are recommended for rice thrips, imported varieties Ruisheng 30% thiazine suspension seed coating agent, and domestic test variety Bailui 35% thiazine suspension seed coating agent.

2. Vegetables: thrips such as eggplant fruits, melons and beans are irrigated with 25% thiazide water dispersible granules 3000-5000 times to reduce the occurrence of virus diseases and the harm of underground pests. Aktai, an imported variety, is a well-known domestic breed of Dagong cattle.

3. Fruit trees: thrips such as mango do serious harm to crops. 25% thiazine spray can be used, but the use should be increased, such as 800 times spray, and can be mixed with avermectin buckets of microemulsions.

4. Tobacco: when tobacco is irrigated before transplanting or sprayed when planting, imidacloprid, thiazide and thiamethylamine can be used, 25% imidacloprid 1000 times, 25% thiazine 3000 times.

Main points of prevention and control of thrips

1. According to the characteristics of thrips lying in the daytime and coming out at night, it is recommended to take medicine in the afternoon.

2. Thrips have strong concealment, so it is necessary to choose internal absorption or organosilicon auxiliaries, and try to choose agents with long effective period.

3. If the conditions permit, the combination of chemical fumigation shed and foliar spray is suggested.

4. Thrips should be prevented in advance, do not wait until flooding before using medicine, grow vegetables during high temperature, if there is no plastic film, it is best to spray the middle and lower parts of the plant and the ground at the same time, because these places are the habitat of thrips nymph.

Symptoms and control methods of thrips in yellow corsage

[harm] Evening jade, gladiolus, orchids, chrysanthemums, roses and other flowers. The adults of nymphs concentrated on the sucking juice of the flowers of the plant, and the grayish-white spots and oviposition marks appeared after the flowers were damaged. When it is serious, it can make the petals curl up and not open smoothly.

[morphological characteristics] the adult female has a brown body, orange chest, 1.2-1.4 mm in length, yellow antennae in section 3, brown in other nodes, two pairs of wings, long and narrow like a rod, with tasseled hairs on the periphery, gray forewings and light base. Egg yellowish, kidney-shaped. Nymphs are smaller and lighter in color than adults, have no wings and have fewer antennal nodes.

[occurrence regularity] more than 10 generations occur in a year. Greenhouses can happen all year round. The female early spawning tube is inserted into the epidermis of petals or stamens to lay eggs under the epidermis or semi-exposed. Nymphs and adults do harm by hiding in flowers. The insect has a variety of feeding habits and can often transfer to each other among different plants. High temperature and drought are beneficial to the blooming of thrips.

[prevention and control method] A. Remove weeds around flower beds and reduce thrips' habitat and breeding grounds. b. When insect pests are found in the growing season, 2.5% deltamethrin EC 4000 times or 50% malathion EC 4000 times can be sprayed for control. Attention should be paid to spraying and hiding places of thrips in flowers when spraying.

Prevention and control of diseases and insect pests of mango thrips

Classified Coleoptera, thrips (Thripidae).

1. Tea yellow thrips ScirtothuipsdosalisHood

1. Harm

The leaves of mango trees damaged by adult and nymphs were scalded by hot water and finally wilted, resulting in brown rough spots on the surface of the fruits. This insect is also harmful to tea trees, bananas and other crops.

2. Morphological characteristics.

The adult body is about 1.0┨ long, yellow, the wing is narrow, long, gray and transparent, the wing margin is hairy, the head width is about 1.8times of the length, the compound eye is slightly gray and black, the single eye is bright red, the antennae are saved as 3 times the length of the head, the width of the forechest is 1.5 times of the length, and the posterior edge has a pair of thick and short thorns.

Egg yellowish, kidney-shaped.

The nymph is milky white when it is first hatched, then becomes yellowish, and looks like an adult.

3. Life habits

The annual occurrence algebra is unknown. The first generation can be completed in more than 10 days when the temperature is high. Both adults and nymphs can damage leaves and fruits; the color of the injured leaves becomes lighter, like hot water scald, and the maximum number of insects in a leaf is 19. The damaged fruit surface shows brown linear lines or markings, causing the fruit surface to be rough and thus reduce the commercial value. This insect is harmful when the mango fruit is soybeans. Usually, the insect body is hidden under the sepals, and when the damage is serious, the small fruit can be withered. The appearance of the injured small fruit shows brown lines (spots). As the small fruit grows, these lines (spots) grow thicker as the fruit grows, and the fruit surface becomes rough when the fruit is ripe.

4. Prevention and control methods

When the insect is found to be harmful, it can be sprayed with 2000 times of dichlorvos or 40% of dimethoate, or 4000 times of 2.5% of dichlorvos or dimethoate. In severe cases, spray once every 7 days, 3 times in a row.

2. Red band thrips Selenothripsrubrocinctus (Giard)

1. Harm

Adult and nymphs damage the leaves of mango seedlings, showing numerous dirty black spots, leaf tips blackening, leaf edges curling, and finally all the leaves fall off, and the whole plant dies; this insect still discharges red liquid feces on the leaves, showing rusty brown or black shining spots after it dries up, affecting photosynthesis. The insect is also harmful to rubber, coffee, cashew nuts, litchi, longan, citrus and other crops.

2. Morphological characteristics.

The adult is long, dark brown, with a body length of 1.0ml 1.5 ┨ and a dense gray-black hairy wing margin.

Ovoid-kidney-shaped, yellowish-white, about 0.25 ┨ long.

The nymph is long and yellow, with a bright red ribbon at the base of its abdomen and a body length of about 1.0 ┨ when it is fully grown.

The pupa is long, with a body length of about 1.0 ┨. It is similar to a nymph in shape, but has fully developed wing buds.

3. Life habits

It takes place about 10 generations a year. The female adult is parthenogenetic and lays eggs on the lower surface of the leaf with a drop of fecal-like substance. The egg stage is 3 days and the pupa stage is 6 days. Adults and nymphs often live in depressions or grooves near the main vein, often raising the end of the abdomen with a spherical droplet at the end.

4. Prevention and control methods

When it occurs, 40% dimethoate or 50% fenitrothion or 80% dichlorvos 1500 times solution can be sprayed to control.