There are two main types of pests: one is to eat the stems and leaves of the plant with the mouth, and enter the stomach after chewing, this pest is called the chewing mouthpart pest; and the other is to use the pointed mouth to pierce into the stem and leaf of the plant, suck the plant juice to cause the plant to wither and die, this pest is called the stinging mouthpart pest.
Stinging mouthpiece pests include aphids, thrips, whitefly (whitefly, whitefly), mites, mites, wood lice, rice planthoppers, blind bugs, etc., there are many species, wide distribution, miscellaneous food, strong fecundity, sucking plant sap, directly causing various symptoms of plants and plants, indirectly spreading virus diseases and various diseases, the harm is very serious!
Now according to the statistics of the national pest resistance monitoring point, the resistance of whiteflies, thrips and aphids of the sucking mouthparter pests has been very high, and the following is a deep analysis of why these sucking mouth organ pests are so difficult to treat!
Whitefly
Whitefly, also known as the little white moth, can harm more than 600 kinds of plants in 112 families, cucumbers, tomatoes, peppers, eggplant, melons, loofahs, zucchini, chrysanthemums are the most harmful, and can also harm beans, lettuce, cabbage, celery, medicinal herbs, tobacco, etc.
Whitefly generally occur from the end of July to the end of September, and greenhouses can generally occur until the end of November. In the spring greenhouse hazard time is from mid-April to late May. The most suitable temperature is 22-30 ° C, preferring to concentrate on young leaves for feeding.
Adults and nymphs suck plant sap with a stinging mouthpiece, causing the affected leaves to fade green, yellow, wilt, and even die the whole plant.
Not only does it suck but it also secretes a lot of honey, which pollutes the foliage and fruit surface, causing coal pollution. At the same time, it causes a large number of fungi to multiply, affecting the normal respiration and photosynthesis of plants, thereby reducing the quality of vegetable fruits and affecting their commodity value.
And whiteflies are also often the vector of viral diseases. Some whitefly can also cause silver leaf disease in zucchini.
Whitefly have tenderness and phototropism, and adults are prone to yellow and green.
Thrips
Thrips occur all year round. Spring, summer and autumn mainly occur in the open field, winter is mainly in the greenhouse, there are many kinds of thrips, known in China there are about 300 species, harmful to eggplant, cucumber, kidney beans, peppers, watermelon and other vegetable crops and citrus, banana, lychee and other fruit tree crops.
Thrips like warm, arid weather, its suitable temperature is 23 ° C ~ 28 ° C, suitable air humidity of 40% ~ 70%, there are many peaks, one is in the autumn or into the winter of November to December, the second is the transition of spring and summer in March and May, especially like to eat in young leaves, flowers, young fruits, heart leaves, curly leaves.
Adults and nymphs file the sap of the young tissues (branches, leaves, flowers, fruits, etc.) of the plant, the young leaves and young shoots of the victims become hard and curled and withered, the leaves become thin, the sides of the leaf midrib appear grayish white or grayish brown stripes or dense small white dots, the epidermis is grayish-brown, deformed, curled, wrinkled, dried, the growth of the plant is weak and slow, and the internodes are shortened;
The flower vessel is damaged, initially white spots, later brown, and gradually withered.
Sucking young fruits will cause the epidermal oil cells to rupture, gradually lose water and shrink, and the scars expand with the expansion of the fruit, showing different shapes of wood bolts silvery white or gray-white spots, and then hardening, scarring, and seriously causing fruit drops, seriously affecting yield and quality.
Thrips are afraid of light, generally day and night, and have a blue tendency.
aphids
Aphids, also known as greasy insects and honey worms, are the fastest-breeding insects. It can harm most plants. There are many kinds of aphids, which are distributed in China for more than 1100 species, and they have existed longer than humans.
Aphids like warm semi-arid weather, the suitable temperature is 15-20 °C, humidity is below 75%, generally spring, summer and autumn are more harmful, spring in wheat, peach trees, spring and summer junction in pepper, melons, peach trees and vegetables. It is especially preferable to gather on the back of the leaves, young stems, flower buds, top buds and other parts for feeding.
Adults and nymphs suck on plant leaves, causing them to shrink, curl, deform, yellow, and wither.
Prickly sucking of stalks, young ears, apical aphids, flower buds, will lead to growth stagnation or delay, flowers decreased or smaller, crop deformity development, early aging, resulting in poor crop growth, poor fruit quality, low yield. Even the whole plant withered and died.
And the excrement honeydew secreted by aphids, transparent and thick, plays a blocking effect on the physiological activities of crops, hinders photosynthesis, and is a good medium for pathogens, inducing soot disease and so on.
Aphids are also important viral media.
Aphids are tender, and adults are yellowish.
Why is it so difficult to prevent
1. Super reproductive ability
Whitefly: more than 10 generations a year, 1 female can lay more than 100 eggs at a time, and more than 400 to 500 eggs. It can lay 3000 to 4000 eggs in a lifetime, and the number of populations can increase by 140 to 150 times after one generation, and the generations overlap, and the number of reproductions increases exponentially!
Thrips: 3-20 generations a year, up to 20 generations a year in the southern region, a female worm lays 22 to 35 eggs at a time, it takes only 14 days from egg to adult, the generation changes quickly, lays many eggs, and is prone to flooding.
Aphids: Aphids have strong fecundity, can reproduce 10 to 30 generations a year, and the phenomenon of generation overlap is prominent. In warm conditions, it takes only 4 to 5 days to complete a generation, and a female can produce hundreds of millions of aphids after hatching in the spring.
2. There are many breeding places and a wide range of hazards
As the area of vegetable cultivation continues to expand, whitefly, thrips and aphids have enough food and breeding grounds throughout the year.
And these sucking mouthparts pests, the general invasion of host plants are very widespread.
There are more than 200 species of whitefly that can invade host plants, almost most melon crops, nightshade fruit crops, cruciferous crops and some legumes.
Thrips can infringe on more than 500 kinds of host plants, a variety of vegetables, flowers, cotton, fruit trees, sugar cane, rice, corn and so on.
Aphids can invade a wider range of hosts, have been on Earth for longer than humans, and most plants can infect and parasitize and reproduce.
3. You can dodge and fly to fight guerrillas
Whitefly: has a strong migration of flight, can fly autonomously for a short distance, a dozen pills will fly away, not easy to contaminate the liquid, even if this piece of land is killed, it will move from another piece of land to fly a few for harm, a few days to breed a generation, after a few days is a large group appears.
Thrips: Thrips have the habit of lying down at night, usually like to hide in flowers, curl leaves and the back of leaves, while eggs are generally in plant tissue, and the medicinal solution is difficult to penetrate, so it is difficult to kill.
Aphids: Aphids also like to hide in the curly leaves and the back of the leaves, and the general liquid cannot penetrate at all. And aphids can also be migrated and transmitted, so it is more difficult to completely kill.
4. The resistance to drugs is very strong
According to the resistance monitoring points conducted by the National Agricultural Technology Center, the resistance of aphids to cypermethrin > 4545 times, and the resistance multiple of imidacloprid to 188 to 316402 times. It has different degrees of resistance to acetamiprid, thiamethoxazine, praiazidone, and cabaret.
The whitefly population is at a high level of resistance to cyanoxamide bromide and moderate to high levels of resistance to agents such as pyridoxine and spironium ethyl ester. A high level of resistance to imidacloprid (resistance multiple is more than 1200 times), a high level of resistance to thiamethoxine (resistance multiple 200-500 times), and a resistance multiple of more than 1000 times to thiazinone.
Thrips are also highly resistant, with varying degrees of resistance to organophosphorus, carbamates, neonicotinoids, pyrethroids and bio-derived agents.
5. The medication is not on the right way, and the prevention and control cannot be legal
The use of drugs is not the right way, the prevention and control cannot be legal, the water is spared at all costs, and the effect of treating insects is poor. Repeated abuse of pesticides, arbitrary increase in doses, etc. cause the insect control effect to be extremely poor, the residual effect period is very short, and even the phenomenon of more and more prevention occurs; in addition, in the actual field control process, there is a widespread misunderstanding of "large amount of medication and small amount of water", which often causes incomplete control of aphids and leaves great hidden dangers for the "comeback" of insect pests.
Generally whitefly, thrips, aphids are on the back of the leaves, curly leaves, heart leaves, and some farmers do not understand the characteristics of these sucking mouth organ pests, in the use of medicine used to the front spray, the back of the leaf always forget to spray, there are some farmers usually spray 400 pounds of water to hit 5-6 acres, the amount of water is not enough, there is no way to beat through. These also lead to unclean beatings, and whitefly, thrips, and aphids reproduce rapidly, and can reproduce in 3 to 5 days, so it looks like bugs can't die.
6, insecticide does not kill eggs, adult insects can not kill impurities
General medicine can only kill adult insects, it is difficult to kill eggs and larvae, resulting in eggs hatching after the adult insects continue, so that the number of drugs can not catch up with the reproductive speed, even if after the drug dies a large piece of adult insects, but for eggs, pupae has no effect, "cutting grass does not remove the root, cure insects do not kill eggs" This often leads to insect pests for a few days.
Because whitefly, thrips, and aphids will have some pests that cannot be completely killed when they are medicated, they will come back after taking the medicine to continue to be harmful, and after a few days, they will flood again. If you can take the drug again at intervals of 1-3 days, the insecticidal effect will be very obvious after two times.
How to prevent better
1. Booby trap avoidance and biological control
Depending on the repellency of the insect infestation, yellow or blue armyworm plates can be hung to trap the adult insects. Or use biological control, such as whitefly can use aphid wasps, grasshoppers, aphids can use ladybugs, aphids, grasshoppers.
2. Change the misunderstanding of medication
Adhere to group prevention and group treatment, continuous medication, to ensure that the amount of medication is sufficient, to wet leaf surface dripping water prevails, the front and back sides of the leaf are sprayed.
It is best to use a compound of insecticidal egg killing, whitefly, aphids can choose ethyl spirant, flufenaceramide, alenopherolamine, thiamethoxine, imidacloprid, matrine, pyritone, etc. or with pyrimethoxyl, thiazide, or the use of Longshida Hongjinlong, reasonable ratio of insecticide and egg killing.
Of course, when playing whiteflies and aphids, orange peel essential oil additives can dissolve the wings of whiteflies, and singles have an insecticidal effect, which is better when dispensing, which can be fast-acting, long-lasting, and assist in insecticidal and egg killing.
Thrips can also increase permeability, using polyficide, polymycin or thistle net plus acryloxachloramine, polybactericide plus thiamethoxam, of course, plus orange peel essential oil is better.