What harm does Spodoptera liturae do to celery? What is the most effective way to prevent it?

In fact, the appearance of this pest will lead to a decrease in the yield of celery, and affect the quality of vegetables, the use of biological control or chemical control methods is more reliable.

It may cause some spots in the celery, which will make the yield of celery decrease, and we should spray the celery with pesticides to prevent pests and diseases, so that it will be fine.

Spodoptera litura's hatchling swarms are infested, and they gradually disperse after the second instar to feed on mesophyll, and enter the gluttony stage after the fourth instar, with 5 and 6 instar larvae accounting for 90% of the total food consumption. The larvae bite the leaves, flowers, buds and fruits, and the leaves are pore or missing, and in severe cases, the whole field of vegetables can be eaten into stalks. The best control period for Spodoptera liturae is from the egg hatching period to the beginning of the second instar larvae.

The agent can be treated with 10% depletion (mitenil) suspension 1500 times, or 1500 times of (emamectin) emulsifiable concentrate, or 4000 times of 15% amperon suspension, or 800 times of 5% methae (lice urea) emulsifiable concentrate, or 1200 times of Caixi (polycides) suspension, or 48% chlorpyrifos emulsifiable concentrate 800 1000 times, or Uranus (bifenthrin) emulsifiable concentrate 2000 times, or 5% antibiotic (fluridin) emulsifiable concentrate 2000 times. The control effect can reach more than 90%.

For water spinach, pinch off the leaves of the long insects, hang a night light, and attract the adults, there is no need to use medicine, because the water spinach grows very fast, you can pinch a stubble in a few days, and pay attention to some insects when washing the vegetables.

In this way, the yield of water spinach will be relatively low, and it will lead to a particularly slow growth rate, and then there will be serious problems with the quality, at this time, it is necessary to kill insects in time, and then spray some insecticides and water more.

It will affect the yield of water spinach, and in this process will also cause a series of damage to the surface, and will also cause a series of economic losses.

Hello There are those special drugs for the prevention and control of cabbage worms Taking cabbage worm as an early land example, the special drugs that can control cabbage worm are dichlorvos, trichlorfon, cyhalothrin, etc. Spodoptera liturae can be controlled by alternately spraying 6 000 8 000 times of 21% killer EC, or 4 000 6 000 times of 50% fenvalerate EC, or 2 000 3 000 times of 20% cyanoma or chrysanthemum EC, or 4 000 5 000 times of Kung Fu and Uranus EC. Spodoptera liturae can also be used on land or in an area to kill 3000 times of emulsifiable concentrate, or 80% of the enemy's group of ascending, or chlorpyramide, or 25% malathion 1 000 times of liquid, or 5% of the stuck gram, or 5% Nongmengte 2 000 3 000 times of liquid, 2 3 times, every 7 10 days 1 time, spray evenly and spray enough.

alternate spraying of 6 000 8 000 times of 21% killing EC, or 4 000 6 000 times of 50% fenvalerate EC, or 2 000 3 000 times of 20% cyanoma or chrysanthemum EC;

or 4 000 5 000 times of Kung Fu and Uranus emulsifiable concentrate, or 3 000 times of 20% emulsifiable concentrate, or 80% dichlorvos, or chlorpyramide, or 25% malathion 1 000 times, or 5% of Jam Ke, or 5% Nongmont 2 000 3 000 times of liquid, 2 3 times, once every 7 10 days, spray evenly and spray the feet.

Taking advantage of the phototaxis of adults, the adults are continuously trapped by using a black light. Before the larvae entered the 3rd instar binge feeding stage, the roots were sprayed with 20 billion pib grams of Spodoptera litura, 12000 15000 times of water-dispersible granules, and 800 times of 45% phoxanthion EC were used to irrigate the roots.

(1) Spodoptera liturae is a pest of the family Spodoptera exigua, which is widely distributed. Adults are 14-20 mm long, dark brown, and have a wingspan of 35-40 mm. The forewings are grayish-brown, the hindwings are white, and the forewings are intertwined with several grayish-white diagonal stripes, with annular and renal striae in between.

The insect occurs in North China in 3 or 4 generations a year, in the Yangtze River basin in 5 or 6 generations a year, and in South China it can occur throughout the year. Adults are diurnal and nocturnal, and have a strong tropism to black light and molasses odors. It prefers to lay eggs on the back of the leaves of marginal crops in densely growing fields.

The larvae mostly swarm near the egg masses and feed on the leaves. After the third inage, they are scattered and harmed, and the time of harm is in the evening. The suitable temperature for development is 28-30 , and the main hazards are in summer.

Around the end of August, it feeds on the leaves of strawberries in nurseries, as well as flower buds, flowers and fruits, leaving only bare petioles. If Spodoptera liturae are present in the planting area, the damage will be more severe after warming in the shed in winter. Mature larvae pupate in topsoil at a depth of 1 3 cm.

When the soil is compacted, it can pupate under dead leaves.

2) Control methods: remove weeds in the field and on the ground, artificially kill eggs or kill young larvae. Use honey and black light to trap and kill. The key to control is to poison the 1 2 instar larvae stage.

It can be sprayed with 5% anti-Taibao (fluridinurea) emulsifiable concentrate 2000 times, or 3% emamectin benzoate microemulsion 2000 times, or 1% matrine soluble liquid 800 1200 times. It can also be sprayed with 800 IU Bacillus thuringiensis wettable powder 100 150 g on 40 50 kg of water. The larvae after the 3rd instar should be sprayed in the evening, because the older larvae like to be active at night.

Spodoptera liturae is a very miscellaneous gluttonous pest, which mainly harms tomatoes in nightshade vegetables. Spodoptera liturae larvae often gather near the egg masses to gnaw on the mesophyll, and the mesophyll on the back of the leaf is gnawed into a gauze mesh, leaving only the epidermis and veins. After the second instar, they began to disperse, and the fifth and sixth instars were the gluttony stage, and each larva could damage 7 10 fruits, accounting for 96% of the total larval food. The damaged tomatoes are inedible, so the yield is seriously affected.

Spodoptera liturae can reproduce all year round in South China without overwintering problems; It is highly likely that the source of insects in the Yangtze River basin migrated from the south. In Zhejiang Province, Spodoptera liturae can occur in 5 to 8 generations a year, and it blooms in July and September. The fastest growing temperature of Spodoptera liturae is 29 30, and the most serious damage is in late August, so it is called a high-temperature pest.

Spodoptera liturae adults are nocturnal and have strong flight ability, which can fly tens of meters at a time, up to more than 10 meters; Adults have phototaxis, and are taxis to sugar, vinegar, wine, fermented carrots, malt, soybean cakes, cow dung, etc. The eggs are mostly laid on the underside of the leaves, and each female adult lays an average of 3 5 eggs, each with 100 200 eggs, and the egg period is 5 6 days at an average temperature of 25. The larvae have a total of 6 instars, and the newly hatched larvae swarm mesophyll, leaving the epidermis and leaf veins, which are easily observed in the field, and the larvae after the 4th instar enter the gluttony stage, and most of them come out in the evening to cause harm.

The following three measures are mainly adopted for the control of Spodoptera litura:

1) Trapping adult insects.

The method of booby-trapping is mainly to use black light to hunt and kill, or to trap with sweet and sour liquid: 6 parts of sugar, 3 parts of vinegar, 1 part of liquor, 10 parts of water, and 1 part of 90% trichlorfon mixed thoroughly. In recent years, the technique of trapping and killing male Spodoptera liturae by sexual traps has been widely promoted.

2) Egg masses are picked and larvae are captured manually.

Egg masses can be picked by taking advantage of the characteristics of concentrated oviposition of adults; It is also possible to take advantage of the characteristics of 1 2 instar larval clusters to remove egg masses; In addition, the method of manual capture of older larvae can be used. The egg masses or larvae removed above are destroyed in a centralized manner.

3) Pharmaceutical prevention and control.

It can be used with 10% Anlubao 1500 times liquid, 20% pyrethuron suspension 1500 2000 times liquid, 5% anti-Taibao + 5% stuck decimation emulsifiable concentrate 1000 1500 times liquid, 5% Ruijinte 1500 2000 times liquid, 10% depletion suspension 1000 1500 times liquid, Nongdile emulsifiable concentrate 1000 1500 times liquid, vegetable and fruit emulsifiable concentrate 500 times liquid, 25% fight special 4000 times liquid, 8010 insecticidal bacteria 500 800 times liquid, 25% insecticidal aqueous agent 500 times liquid +Dichlorvos EC 1000 times liquid spray, 48% Lesben EC 800 1000 times liquid, etc. The time of pesticide control should be mastered in the 1 2 instar stage, and the larvae above 3 instars are dispersed into the fruit, and the control effect is greatly reduced.

(1) Habits and hazard characteristics: Spodoptera liturae belongs to the family Spodoptera exigua, which is a gluttonous pest with a very mixed diet. The first hatched larvae were swarmed, and after the 2nd instar, they gradually dispersed and fed on the mesophyll, and after the 4th instar, they entered the overfeeding stage, and the 5 and 6th instar larvae accounted for 90% of the total food consumption.

The larvae bite the leaves, flowers, flower buds and fruits, and the leaves are holes or missing, and in severe cases, they can eat the whole field crops into stalks.

Adults are 14-20 mm long, wingspan 35-40 mm, dark brown with white bush hairs on the back of the thorax and dark brown bush hairs on the sides of the abdomen. Forewings grayish-brown, inner and outer transverse lines grayish-white wavy, with 3 white diagonal stripes in the middle, hindwings white. The eggs are flattened and hemispherical, yellowish-white at first lay, purplish-black before hatching, and covered with grayish-yellow villi.

The mature larvae are 35 to 50 mm long, and the larvae are divided into 6 instars. The head is black-brown, and the color of the thorax and abdomen varies greatly, such as earthy yellow, blue-yellow, gray-brown, etc., and there are a pair of half-moon-shaped or triangular black spots from the middle chest to the dorsal surface of the ninth abdominal segment. Pupae 15-20 mm long, reddish-brown, with a pair of short spines at the end of the tail.

Spodoptera litura, which occurs in 5 6 generations a year in Hainan Province, is a thermophilic pest, with a suitable temperature of 28 30 and a serious damage period of 6 September. Adults are nocturnal and nocturnal, with the most active activity at 8 to 12 o'clock in the evening, with phototaxis, and taxis towards sugar, wine, vinegar and fermented substances. The eggs are mostly laid at the leaf vein bifurcation on the back of the leaves in the middle of the plant, and each female lays 3 5 eggs, each with about 100 more than 100 eggs.

When large occurrences, larvae have the habit of migrating in groups and have the tendency to fake death. After the older larvae enter the gluttony period, they generally hide in the shade or in the soil crevices during the day, and mostly come out after the evening to carry out activities, and the mature larvae pupate in 1 3 cm of topsoil or under dead branches and leaves.

2) Control measures: trapping and killing adult insects. Use the phototaxis and chemotaxis of adults to trap and kill, you can use black light and frequency vibration lamp to trap moths, or you can use sweet and sour liquid or carrot, sweet potato, soybean cake and other fermentation broth, add a little brown sugar, trichlorfon for trapping.

Artificial killing. Taking advantage of the characteristics of adult eggs and clumps and incubated larvae swarming, artificial egg picking and larvae were eliminated in combination with field management. Biocontrol.

In the initial incubation period of larvae, it was sprayed with 1500 times of the compound virus insecticide insect plague No. 1, and the effect was better. Chemical control. Catching the larvae in the stage of cluster damage and spotting before the 3rd instar can be combined with field management for picking, and there is no need to apply pesticides in the whole field.

After the 4th instar of the larvae, due to the diurnal and nocturnal damage, the application should be carried out around the evening. The following agents can be used: 5% anti-Taibao EC 3000 times, insect ba, 5% Ka Ke EC 2000 times, 2000 times 2000 times 20% chrysanthemum EC, 40% cyanochrysanthemum vinegar 5000 times, Uranus EC 3000 times, 48% Lesben EC 1000 times, spray once every 7 10 days, 2 3 times.