What's wrong with Jasmine Bug?
Photo: Jasmine potted plants
First, the two-horned borer.
This insect belongs to Coccinellidae and Coccinellinae. It is known to occur in low mountains and plains in May-June and August-September in Japan, and it harms the flowers and fruits of rats. It is found that it harms jasmine in China, commonly known as jasmine stem borer. The masses call it a flower boring bug.
Life habit: overwinter as larvae on the tender branches and residual flowers of jasmine. At the end of February and the beginning of March, the pupae will warm and emerge. Adults lay eggs on tender buds or leaves. After hatching, the larvae burrow into the flowers and eat them. When there are no flowers, they hurt the leaves in the leaves, which can be turned into harm. Larvae can also harm shoots, which occurs for more than ten generations every year. It is observed that this insect infects Jasmine in the whole flowering period, with overlapping generations, and its infection peak is from June to September.
Control method of jasmine double-striped corn borer
This insect mainly harms flowers, and jasmine is the raw material for scenting scented tea, so the safety requirements are particularly high. In the prevention and control, first of all, we should pay attention to not using high-toxic and high-residue pesticides during flowering, avoid using drugs as much as possible during flowering, and control the population density through prevention and control before and after flowering. Specific methods:
1. Clear the fields in winter, cut off all dead branches, damaged branches and insect branches, and burn them centrally. Sweep the fallen leaves, burn or bury them. Check the fields with many overwintering insects, and reduce the source base of overwintering insects by applying pesticides.
2. Pay attention to check the flowering period, and all damaged buds, flowers and branches should be removed in time.
3. Smoking in the flower field at dusk to prevent adults from laying eggs.
4. Chemical control. You can choose 24.5% pyridaben 2000 times solution or 1.8% chlorfenapyr 2000 times dilution, or 800- 1000 times solution of sanle pesticide, or other avermectins, such as 0.9% avermectin 2000-3000 times solution and 1% bromine.
Second, the jasmine leaf moth.
Jasmine leaf moth belongs to LEPIDOPTERA, Mothidae. Mainly feed on the leaves of jasmine by larvae, sometimes endangering buds and branches. Newly hatched larvae gather on the back of leaves and feed on mesophyll, leaving a translucent epidermis. When you grow up, eat leaves into holes or bite them into notches. It can also eat the cortex of branchlets, causing the leaves to wither and fall off and the whole branch to die.
Life habit: it occurs once a year in the south 10 generation, and overwinters as larvae. Adults appear from March to April, dormant during the day, active at night, mating and spawning. Eggs are mostly produced on leaves, but also on leaf backs and branchlets. Eggs are arranged in scales, and each female can lay 50 ~ 200 eggs. Larvae gather first, then spread after the third instar, and often connect branches and leaves together, hide them and feed on them. Autumn is more harmful.
Control methods of jasmine leaf borer
1. Clear the garden in early spring, sweep away the dead leaves and burn them to eliminate the overwintering insect source.
2. Biological control. Including protecting natural enemies, spawning parasitic bees and using biological pesticide Bacillus thuringiensis.
3. Chemical control. When the enemy can't control its harm, it can also use 90% trichlorfon 600 ~ 800 times dilution, 50% chlorpyrifos EC 1000 times dilution, 2.5% deltamethrin 1500 ~ 2000 times dilution, or 20% fenvalerate 2000 ~ 3000 times dilution. Note that spraying should be carried out after picking flowers, and pyrethroid pesticides can only be picked more than 5 days after application.
Photo: Spodoptera litura
Three. prodenia litura
Spodoptera litura belongs to Lepidoptera, Noctuidae, also known as Spodoptera litura and Noctuidae. Spodoptera litura is a worldwide pest, mainly distributed in tropical and subtropical Asia, Europe, Mediterranean and Africa. It is distributed all over China. This insect is an omnivorous, gluttonous leaf-eating pest, which often erupts intermittently. There are more than 200 species of plants known to be harmful to 99 families, and there are at least 99 favorite plants. In cultivated crops, it mainly harms jasmine, cotton and so on. Larvae mainly feed on leaves, but also eat flowers, fruits and twigs. This insect occurs more frequently in warm areas south of Huaihe River in China, with more populations in the middle and lower reaches of Yangtze River and South China, and occasionally in the north.
The occurrence and harm of Spodoptera litura are affected by many factors, such as temperature, humidity, soil, rainfall, host plants, natural enemies and human measures. The optimum temperature for growth and development is 25 ~ 30℃, and the optimum relative humidity is 75% ~ 80%. Insect population density is generally higher in fields with good water and fertilizer conditions and dense growth. 20% soil water content is helpful for pupation of larvae and emergence of adults. If the newly hatched larvae are washed by heavy rain, they will die in large numbers, and long-term water accumulation in the field is not conducive to the survival of pupae. In Guangxi, the temperature and humidity conditions are most suitable for the growth and development of Spodoptera litura. If there is no continuous rainstorm in June, it will be beneficial to the outbreak of insect population.
Control methods of Spodoptera litura
1, trapping and killing adults: using the phototaxis and chemotaxis of adults, trapping and killing adults with black light and poplar branches or sweet and sour.
2. Artificial egg killing: According to the characteristics that adults tend to lay eggs on the back of the leaves in the middle of the plant, and larvae feed in groups, the egg pieces should be removed in time before the spawning season and the larvae spread, so as to kill the adults.
3. Chemical control: During the vigorous larval growth period, EC 4000 times, 4.5% beta-cypermethrin EC 3000 times and 52.25% Agrocybe EC 65438+ were obtained by eliminating suspending agent 1.500 times, 5% Ruijinte suspending agent 2500 times and 5.7% 100% ripening.
Fourth, orange-gray image
Citrus gray elephant belongs to COLEOPTERA, Elephantidae. It harms jasmine from March to May every year. Adults eat buds, buds and leaves in addition to old leaves. Young and old leaves were carved and all of them were seriously eaten up, which greatly affected the first batch of flowers in late April and early May. According to preliminary investigation, there are more than 20,000 insects per mu in jasmine fields along sandy loam in Hengxian County. Known hazards of citrus gray elephant: citrus, tea, jasmine, etc.
Control method of citrus gray image
Artificial killing: The insect has no hind wings, can't fly, moves slowly, and has strong ability of feign death, so it can be killed by artificial capture.
Chemical control: it is appropriate to spray pesticide at the peak of adult development. The following chemicals can be selected: 30% mirex 1000 times solution, 4.5% beta-cypermethrin 1000 ~ 2000 times solution, or 2.5% kung fu 1000 ~ 2000 times solution, and some dichlorvos spray can be added appropriately. Highly toxic pesticides such as methamidophos and 1605 are not suitable for use because of their high toxicity and long residue period.
Photo: flower thrips
Five, flower thrips
Flower thrips belong to the genus Thysanoptera thrips. This insect destroys the corolla and stamens in flowers, especially around the ovary, and destroys the reproductive organs. After the corolla is damaged, stripes or spots appear, which can make the corolla deformed, wilted and dried up, which has a great influence on the ornamental value. After the leaves are damaged, silver-gray stripes often appear on the new leaves of tender stems, or the leaves are all silver-gray, which causes deciduous leaves and affects growth.
Life habit: one year 1 1 ~ 14 generations, with overlapping generations. Overwintering as adults. Adults have strong phototaxis. There are dozens to hundreds of adults and nymphs in a slightly fragrant stamen, and the corolla is very large. Eggs are mostly produced in petals, filaments and tender leaves, and the spawning ground is slightly enlarged or slightly raised, which can be inspected by light. Each female lays 77 ~ 248 eggs, and the spawning period is as long as 20 ~ 50 days.
Control methods of flower thrips
Use chemicals to prevent and control. Spray 500-800 times of 2.5% Skin Spring EC, 800- 1000 times of 3% pyrethrin EC, 1000 times of 50% fenvalerate EC, 1000 times of 20% fenvalerate EC or 25% quinalphos emulsion.
Six, cotton red spider
Cotton spider is also called Tetranychus urticae and Tetranychus gossypii. It belongs to acaridae and Tetranychidae, and it is an important pest mite. Cotton spider is omnivorous, with strong reproductive ability and rapid diffusion, which can harm dozens of plants, including corn, melons, beans, vegetables, trees and weeds. Jasmine is one of the most common harmful plants. The insect sucks the host juice on the back of jasmine leaves or flower buds with adult mites, juvenile mites and nymphs, which makes the damaged leaves lose their green color, turn white obviously, turn yellow seriously and even appear rust spots. When the bud is damaged, it will shrink or close, which greatly affects the yield and quality of flowers.
Cotton spiders can drift with the current, spread by the wind, crawl and spread over short distances. Generally speaking, the climate is dry and high temperature is beneficial to its reproduction. The optimum temperature is 29 ~ 365438 0℃ and the relative humidity is 35% ~ 55%. If the air humidity exceeds 70%, its reproduction will be inhibited. There are many natural enemies of cotton spiders, such as lacewings, carnivorous mites, thrips, ladybugs and so on. All these have played a very good role in preventing and controlling cotton spiders.
Control methods of cotton red spider
1, agricultural control (1) Eliminate weeds in the field, combine pruning, remove diseased leaves, remove fallen leaves, and burn or treat them, which can eliminate the source of overwintering insects and reduce the harm. (2) Strengthen the management of water and fertilizer to enhance the insect resistance of plants. Keep the humidity and worsen the living environment of cotton spiders.
2. Chemical control: 24.5% propargite or 1.8% propargite diluted 2000 times, or 50% tricyclic tin wettable powder diluted 1.500 times, or 75% propargite emulsifiable concentrate diluted 1.000 times, or 35% Saidan emulsifiable concentrate diluted 35 times.
Photo: Snail
Seven, snails
Snails belong to mollusks, not insects. Taxonomically, it belongs to Gastropoda, Amphibia and Snail. Commonly known as buffalo, snail and hard shell worm. There are two kinds of snails common in farmland, the homotype snail and the gray snail, and the homotype snail is the main one. Snails eat all kinds of food, except jasmine, vegetables, beans, hemp, tobacco, tea, cotton, green manure, bananas, fruit trees, weeds and so on. On jasmine, all branches, young leaves, old leaves and even stems are damaged. They often eat in groups, eat up young buds or bite off the cortex of branches, which makes the whole branches wither, or bite the leaves into nicked, perforated and tattered leaves, which seriously affects the yield.
Methods of snail control: agriculture and manual control
1, often cleaning the garden, cleaning and burning the dead leaves on the ground of crops, especially the branches and leaves trimmed before winter, is one of the places to provide snails with wintering, and they can't stay in the garden for wintering.
February, April and May, September and June, and 65438+ 10 are the snail spawning seasons. Combined with intertillage weeding, the topsoil of crop roots is plowed and exposed to the sun to kill eggs.
3. In the peak period of Oncomelania snail activity, it is exposed and fed in the morning and evening or on cloudy days, and artificial capture is adopted.
Pesticide control: 30% chlorhexidine can be used, per mu 100 ~ 500g, and the bait is 2 ~ 3kg (corn flour, bran, peanut cake, etc. ), can be mixed with water to form small particles, and the control effect is very good. You can also use 300-500g molluscicide, 350g 6% molluscicide and 10% molluscicide per mu, mix and dry fine soil or fine sand, and sprinkle them evenly on snail crops and the ground at night, or spray them with warm water or a water sprayer after dissolution. 70% Balosha Wettable Powder 1000 Diluent Spray Killing. If it rains after application, it should be applied again. Or sprinkle lime powder, 3 ~ 5 kg per mu.
Photo: Jasmine eaten by insects.
Tips Insects on jasmine flowers don't have to be treated with chemicals. You can make your own insecticidal water with some small things in life first, and then use chemicals when it is not possible. After all, pesticides are toxic, so it is not safe to use them at home. If you want to know the method of self-made insecticidal water, you can pay attention to the previous article of Uncle Gardener.