Thrips (Thysanoptera), either vesiculate or fringed, is a very small order of insects that can be found on any of the continents. Karl de Geer first described thrips in 1744, and today more than 6 thousand species of thrips have been identified, which are combined into more than 100 genera.
Features of thrips
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The body of thrips can be colored brown, black or gray, while its length varies from 0.05 to 0.3 cm. In some species, the body of the insect is larger – about 1.4 cm. The mouth apparatus of thrips is piercing. sucking, asymmetric, legs are running, there are no claws on the paws; instead, they have teeth and suction devices of a bubble shape. The abdomen consists of 11 segments, and there is a fringe on the edge of the wings.
The development of such an insect goes through 5 stages, namely: eggs, larvae, pronymphs, nymphs, and imago. The body color of the larvae is yellowish-white or pale gray, and they differ from the image only in that they do not have wings. Thrips are polyphages, which means that they are omnivorous insects. They are considered one of the most common harmful insects in vegetable, ornamental, agricultural, fruit, and indoor crops. Indoors, thrips are the most dangerous, for example, if they appeared in a greenhouse, then it is almost impossible to exterminate them, you can only restrain their population.
It is difficult to find thrips on plants because they are very small and lead a hidden lifestyle: they often live on one bush for a long time, without moving on to neighboring plants. Adult insects, as well as larvae, feed on sap, sucking it out of the aerial parts of the bush while infecting it with their secretions. Initially, in the area of the bites, specks of light yellow color or discolored are formed, as well as stripes and streaks, over time they increase in size and connect to each other.
The result of the life of thrips is the dying off of plant tissues, where there were spots, holes appear over time, withering and flying of foliage is also observed, flowers lose their decorative effect and wither ahead of time. If the occupation of the bush is massive, then on its aerial parts one can see silvery areas, the shoots become curved, and the flowers become deformed (as a result of injury to the flower bud). In addition, thrips are among the main carriers of viral diseases that are currently considered incurable.
In order to protect indoor plants from thrips, do not forget about certain preventive measures:
- Maintain an optimal humidity level in the room. Remember that thrips, like spider mites, prefer low humidity, so install an electric humidifier in the room or systematically humidify it with a fine atomizer.
- Conduct a systematic inspection of indoor flowers, pay special attention to the seamy surface of the sheet plates. As soon as the larvae or adults are found, give the plants a warm shower as soon as possible.
- Experts advise, at least once every 30 days, to arrange a shower for home flowers, this will help rid the plant of dust, adult insects, and pest larvae.
- Place or hang glue traps between the flowers: you can use fly strips or yellow or blue paper strips to which the adhesive is applied. In this way, you can not only understand whether there are thrips on plants but also significantly reduce their number.
- Flowers brought from a friend or bought in a store are recommended to be quarantined for 15–20 days, that is, they should be kept away from other plants and watched.
How to get rid of thrips on houseplants
If a silvery film has formed on the foliage of the orchid, and small dots and strokes on the seamy surface, then this indicates that thrips occupied it. These lesions are very similar to those that remain after spider mites, but in this case, the bite marks are more pronounced. Thrips are quite difficult to find because even with a small threat they quickly hide in the soil mixture. They can also easily move from one flower to another with the help of their wings.
As soon as you notice the first signs of thrips presence, immediately rinse the brush thoroughly under a warm shower. After that, with a sharp sterile instrument, cut out all the affected areas to healthy tissue, and then treat the cut sites with charcoal powder and moisten the bush from a sprayer with Actellik or Fitoverm solution. The bush is processed only 3 times with a break of 1.5 weeks. Until you completely destroy all thrips, the flower is quarantined. If there are few pests on the plant, then you can, if desired, replace pesticides with folk remedies, for example, oil-water or garlic or onion infusion.
As a rule, the florist realizes that thrips have settled on the violet even when most of the bush has suffered. However, there is a method that will help get rid of this harmful insect very quickly. When two or three days remain before processing, water the flower abundantly. Immediately before processing, it is necessary to wrap the container with a plastic bag, which will help protect the substrate during processing from the ingress of the solution. First, dust is washed off the plant with a stream of water, which should be warm.
Then the plant is lowered “upside-down” into a deep container, which is filled with the following solution: one ampoule of Fitoverm is dissolved in 5–6 liters of warm water, and 25 to 30 milligrams of animal shampoo against fleas is also added. During the mixing of the solution, foam forms on its surface due to the shampoo, all of it should be removed. The remains of soap flakes on the surface of the solution are removed with toilet paper. Remove the bush from the solution after 10 seconds, try to glass as much water as possible from it, for this, they turn it over very slowly.
Do not shake the flower or twist it, trying to shake off the liquid drops from it. Then the bush is placed on the table and the package is removed from it, after which the soil mixture in the pot is abundantly spilled with a solution of Fitosporin-M or Aktara (it must be prepared according to the instructions). After the violet has been processed, it is quarantined for a while in order to understand whether you managed to destroy the thrips the first time or not.
Thrips on horticultural and horticultural crops
Thrips are most commonly found in greenhouse cucumbers. They can be found on the seamy surface of young leaf plates, where they suck the juice from the plant. This leads to a slowdown in the development and growth of the bush. In the area of the bites, you can see spots of light color, while they are located very densely. Also, areas of a silvery color are formed on the foliage – this indicates that air has entered the leaf plate. These pests are distinguished by the fact that they multiply very quickly, in this regard, as soon as the first signs of the presence of thrips on cucumbers are found, it is necessary to immediately begin to combat them.
If the insects have not yet had time to multiply strongly, then an infusion made from celandine, garlic, or onions can be used for processing. If there are a lot of pests, then folk remedies will be ineffective, so without wasting time, spray the bushes with pesticides, for example, a solution of Avertin N, Aktara, or Imidacloprid (prepare the solution in accordance with the instructions). Always wear rubber gloves, a respirator, and goggles before proceeding. In order to get rid of this pest completely, you will need more than one treatment.
Onions are home to tobacco onion thrips, which damages both the bulb and feathers. But at first glance, it is very difficult to determine that plants are suffering from thrips. Carefully examine the bush, if there are very small black dots on its surface, and there are light specks in the leaf sinuses that outwardly resemble drops of mercury, then this indicates that the bush is occupied by thrips. Over time, the yellowing of the foliage is observed, and it begins to turn yellow from the top. Then the foliage dies off. The development of the bushes slows down and they form small bulbs. Garlic is least often affected by thrips from onion crops, and shallots are also highly resistant to insects. This insect can inflict the greatest harm on onions.
In order to protect onions from pests, be sure to follow the rules of crop rotation. In the area where garlic or onion was grown, it can be planted again only after at least 4 or 5 years. After the crop is harvested, remove all plant residues from the area and destroy them. Also, in the autumn, they must dig up the soil on the site, since thrips hide in the ground for wintering to a depth of 70 mm. If the onion was grown in a greenhouse, then after harvesting it is processed with Karbofos. Remove all weeds from the site in time, and do not forget to disinfect the planting or sowing material before planting.
If the pest is found, then the storage, where the set and the onion are located, are necessarily fumigated, for this they use sulfur gas: 1 kilogram of sulfur is enough to process one square meter of the room. To exterminate thrips in the garden, they use Aktar, Fufanon, Golden Spark, Vertimek, Aktellik, Mospilan, Fitoverm or Karate. In recent years, gardeners are increasingly using the Spintor insecticide to process onions (treatments are carried out regularly at a frequency of 1 time in 10 days). Together with treatments with pesticides, sticky traps are also used. If there are not very many insects, then you can fight them with the help of herbal infusions (tobacco, onion, or celandine) or a decoction of the zest.
Gladiolus thrips are very dangerous for gladioli. When the weather is dry and hot, the reproduction of the pest occurs fastest: within one season, it can give up to 7 generations. Insects can greatly harm the opening inflorescences, the larvae, and adults, once in the bud, begin to suck the juice from the delicate petals. After the rain passes, the damaged buds turn brown, as if burnt. Those buds that are very badly injured dry out without blooming. In those bushes where thrips have settled, the replacement bulb is formed very small and weak, and if you put it in storage, it will die. In autumn, the pest is buried in the ground and settles on the bottom of the bulbs. By storing such corms, you bring the thrips into storage.
To protect these majestic flowers from thrips, do not forget about preventive measures:
- in autumn, remove from the site all plant residues that are destroyed or laid in compost;
- carry out a mandatory digging of the site;
- before removing the bulbs in storage, they are sorted out, removing all specimens with punctures, mechanical injuries, and bites;
- healthy bulbs before harvesting for storage are immersed in a solution of Karbofos for 30 minutes, then they are washed under running water, thoroughly dried, and placed in storage (the temperature should be no more than 5 degrees, this contributes to the death of the pest);
- in the spring, before planting the bulbs, they are again treated in a solution of Karbofos.
From mid-June, they begin a cycle of flower treatments with insecticidal preparations, and they must be alternated. For example, you can treat the bushes twice with a solution of Actellic or Karbofos, and then the plants are sprayed with Decis. The first 2 times gladioli are treated with a break of 7-12 days, and the third spraying – 25-28 days after the second treatment.
Thrips on roses
Most often, thrips on garden roses settle in buds, where they suck the juice out of them. As a result, buds damaged by the pest may not bloom and dry out quickly. Since such an insect multiplies very quickly and rapidly spreads through the bush, it is capable of destroying all roses in a short time. Therefore, it is necessary to begin to fight it immediately after the first symptoms of the presence of thrips are detected. Both in the garden and at home, roses from such a pest are treated with a solution of Aktara, Inta-vira, Fitoverma, or Commander.
With a solution to one of these insecticidal preparations, the soil around the plant should be shed regularly once every 15 days. To make the product more effective, it is recommended to pour in a little zoo shampoo or add green soap crushed on a grater. To treat the bushes themselves, pesticides are not used, as this can cause the death of bees. Those buds that are already damaged by the pest are cut off because they can no longer be saved. However, you can keep healthy buds from being hit by thrips.
Thrips remedies (drugs)
Chemicals are the most effective in the fight against thrips. The following insecticidal preparations will be described that are used in the fight against this pest:
- Agravertine. This enteric biological agent is used for the extermination of sucking insects and is highly effective. Solution preparation: 10 milligrams for 1 liter of water.
- Aktara. Such a drug with an intestinal action is highly effective and is very quickly absorbed by plants.
- Actellic. An organophosphorus preparation of a wide spectrum of contact-intestinal action, it is used in the fight against ticks, sucking, and leaf-eating pests. Solution: one ampoule for 1 liter of water.
- Vertimek. It is an insecticidal acaricidal agent with an enteric action, which is used to protect crops in the greenhouse, as well as indoor flowers. Solution: 2.5 milligrams per bucket of water.
- Decis. A broad-spectrum contact agent, which is effective in the fight against sucking and leaf-eating pests, and it exterminates both larvae and adults.
- Imidacloprid. This drug is able to exterminate various pests. It is used as an active ingredient in the manufacture of various modern drugs.
- Inta-vir. The tool is used to destroy various pests in the garden and horticultural crops, both in the open field and in the greenhouse. It is not dangerous for humans and pets. Solution: one tablet for 2 liters of water.
- The spark is golden. Such a highly effective drug is used in pest control.
- Karate. This highly effective contact agent is excellent at killing pests. Solution: 2 milligrams per bucket of water.
- Karbofos. The pesticide, which is characterized by moderate toxicity, is used in the fight against pests of vegetable and fruit crops, grapes, and citrus fruits. Solution: for 1 liter of water 7.5 milligrams.
- Mospilan. This systemic tool acts very quickly, it is able to exterminate pests at any stage of development.
- Spintor. This biological agent has a unique mechanism of action against many pests.
- Fitoverm . Such a biological agent, made on the basis of the vital activity of soil microorganisms, is used to protect indoor flowers from harmful insects. Solution: for 100 milligrams of water, 1 milligram of the product.
- Fufanon . A broad-spectrum organophosphorus drug is distinguished by intestinal, contact, and fumigate action.
Fighting thrips with folk remedies
Despite the fact that folk remedies are not as effective as compared to pesticides, they are less toxic to bees, domestic animals, humans and birds. In this regard, if there are not very many thrips on the plants, you can try to get rid of them with folk remedies. They are also often used for preventive treatments.
- 1 tbsp. combine water with 1 tsp. onions or garlic, which is pre-chopped. The infusion will be ready after 24 hours, it remains to be filtered and you can start processing indoor flowers.
- A 0.5 liter can is filled with dry marigolds and so much water is poured in so that the container is full. After two days, the finished infusion is filtered and the culture is treated with it.
- 1 liter of warm water is combined with 50 grams of fresh roots or dandelion foliage. After 3 hours, the infusion is filtered and used to treat plants with thrips.
- Add 100 grams of pharmacy chamomile to a liter of water, mix everything well, and leave for 12 hours. In the strained infusion, dissolve 5 grams of green soap crushed on a grater, after which the bushes affected by the pest are sprayed with it.
- A liter of water is combined with ½ tbsp. tobacco dust or crushed dry tobacco and leave for 24 hours. Pour another liter of water into the composition, mix everything thoroughly, and use to spray plants from thrips.
- In 1 st. water add 50 grams of dry tomato foliage. The infusion will be ready after 3 hours, it is filtered and the volume is brought to one liter with clean water. Various cultures are processed with it.
- 100 grams of dried or 50 grams of fresh celandine (crushed shoots and foliage) are combined with a liter of water, the product will be ready after 24 hours. Then it is filtered and used to spray the bushes from thrips.
- Finely chopped garlic is poured into a small container, or turpentine is poured in, then it is installed directly in a flower pot to an indoor flower affected by thrips. After that, the bush is covered with a plastic bag for three hours.
Types of thrips
It was already mentioned above that there are many species of thrips in nature, and most of them are omnivores. However, the following species most often harm indoor, garden, garden, and greenhouse crops:
Common thrips (Frankliniella intonsa)
The length of the dark-brown beetle is up to 0.12 cm; it is a wide polyphage that can inhabit various cultures. It sucks the juice from flowers and ovaries. Berry, vegetable, ornamental, and fruit crops can suffer from it. The species can be found throughout the Palaearctic.
Floral western thrips
Floral western thrips, or California thrips (Frankliniella occidentallis). This pest is also a wide polyphage that affects a variety of crops grown both in the greenhouse and in the open field.
Decorative thrips (Hercinothrips femoralis)
The color of such an insect is dark brown, and in length, it reaches about 0.17 cm, it prefers to settle on all ornamental crops: on orchids, gardenias, cacti, calla lilies, dracaena, chrysanthemums, crotons, begonias, coleus, palms, and also on commeline and bulbous plants. In mid-latitudes, as well as in regions with a cool climate, this species is most often found indoors.
Dracaena thrips (Parthenothrips dracaena)
Brownish-yellow females of this species reach about 0.12 cm in length, while males are lighter and smaller. Such insects settle on aralia, ficus, hibiscus, and also on commeline and aroid plants. Other cultures can also be damaged by them. In nature, they can be found in areas with tropical and subtropical climates, and in areas where the climate is cooler, they damage crops in the closed ground and indoors.
Rose thrips (Thrips fuscipennis)
The length of the brown body in this species, which is a wide polyphage, is about 0.1 cm. This insect prefers to settle on rosaceous plants grown both in the open and closed ground. They can be found in buds and flowers.
Tobacco thrips (Thrips tabaci)
This insect can harm many crops, while most often it settles on umbrella and nightshade plants. The color of the female can vary from brown to yellowish. The length of an adult is about 0.1 cm. In nature, such pests can be found in Ukraine, in the southern part of Russia, and in Central Asia. In the north, such thrips are found indoors and in greenhouses.
Bulbous thrips (Liothrips vaneeckei)
This widespread insect has a dark brown body, which reaches a length of about 0.2 cm. It settles between the scales of the bulbs.
This insect can damage both ornamental and cultivated plants, but cereal crops most often suffer from it: rye, barley, oats, corn, and also buckwheat, cotton, and tobacco. And also this pest settles on weeds. It is a dark-colored beetle, the body length of the male is about 12 mm, and the female is twice as long.
In the fight against thrips, it should be borne in mind that scientists have discovered elements of social behavior in them. This insect, like bees or ants, can gather in large groups to guard larvae and clutches, and it has also been noticed that they pave odorous paths for group coordination.