Many indoor plant lovers are familiar with an insect called flower thrips. This is a pest. Science knows several thousand of its varieties. As a rule, the insect feeds on agricultural crops, but it often chooses ornamental plants.
Description of the pest
Western California thrips (photo can be seen in the article) is a representative of the thrips family of the genus Frankliniella. Body length does not exceed 1.5 mm. The color is pale yellow or brown. The body is elongated, smooth. The palpi are three-segmented, the antennae eight-segmented. The edge of the forehead is shifted towards the mouth. The mouth cone is of a piercing-sucking type, which is characteristic of parasitic insects on plants. In females, the ovipositor is bent down.
The abdomen, consisting of 10 segments, has a dentate comb on the eighth tergite. The limbs are shortened, running, at the ends of the legs there are bubble-shaped suckers. Thrips have a pair of narrow long wings with pointed tips. On the edges they have cilia. Thanks to this structure of the wings, thrips are able to fly from place to place in search of food and while laying eggs. Insects show sexual dimorphismthe female is larger in size.
Lifestyle and harmfulness
Insect leads a secretive life. The western flower thrips is a typical polyphagous and feeds on over 250 plant species including tomatoes, peppers, cucumbers, peaches and lettuce. Often it can be found on flowers: roses, carnations, cyclamens, gerberas. Adults suck juice from stems, leaves, flowers and fruits.
Species that live in warm regions winter in open ground, the insect is not capable of enduring Russian frosts. They wait for the cold season in greenhouses, the larvae hide in the soil, and the adults in the remains of plants.
The spread of the insect occurs through the importation of infected fruits, ornamental plants, flower seedlings and vegetable crops. The nearest movement occurs during the transfer of thrips on shoes and clothes, the flight from a neighboring site. The females lay their eggs in the tissues of the plant so that it is impossible to distinguish between them. By cutting the flowers, you can move the pest home or to the greenhouse. In the warm season, thrips are selected from greenhouses and spread around the area.
The insect spends its entire life cycle on plants. Thrips (the photo on the leaf of the flower is presented below) feed on its juice and damage tissues. They, in turn, grow more slowly, yields decrease, flowers and leaves fall off, and the fruits lose their external attractiveness. A distinctive sign of the presence of a parasite on plants is the formation of black dots and dry spots of light color on the leaves. Among other things, thrips carry some viral diseases.Weakened crops as a result of the vital activity of insect colonies are susceptible to the spotted wilt virus, which can destroy more than a thousand plant species.
Thrips is an insect with partial metamorphosis. Development is determined by the following stages: egg, larva, pronymph, nymph, imago. As a result of mating, females are able to lay up to a hundred eggs on petals, stems, and in plant tissues. Eggs are oval, light, about 0.2 mm in size. The timing of its ripening largely depends on the air temperature. At +25 °C, the formation of the embryo occurs in three days, at 15 °C - in 11 days. At birth, male larvae emerge from an unfertilized egg.
The larva has a pale yellow color, similar to the color of adults. Offspring, as a rule, are born at the same time, in one area you can observe a group of small pests. The larvae go through two stages, after their completion they pass into the pronymph, and after that - into the nymph. They penetrate the soil, and after one to three days an adult (imago) appears. In a favorable environment, the entire generation development cycle takes 12 days. Up to 15 generations of the parasite can change in a year under greenhouse conditions.
First signs of plant infection
Due to the fact that the insect leads a secretive lifestyle, it is not always possible to detect the first foci of affected plants. However, there are clear signs of thrips infection:
- miniature puncture dots on plant leaves indicate that parasites drank juice in these places;
- sometimesunreasonable discoloration of the leaves also indicates the presence of pests;
- brown, brown and silver spots can be found on leaves and petals - these are damage caused by the parasite;
- dying off and falling of leaves indicates an advanced form of plant infection;
- deformation of flowers, stems, fruits can be caused by thrips;
- black dots and sticky secretions on the surface of the plant are a waste product of the insect.
Thrips most often start on plants that do not like frequent watering and spraying, as pests prefer dry, warm air.
Reasons for appearance on indoor plants
The appearance of thrips on indoor plants (a photo of the pest can be found in the article) is associated with the conditions for their reproduction and penetration into the house. Considering this, you should pay attention to the following factors:
- Often they enter the room through an open window while airing the room. In addition to the fact that thrips can fly long distances, they can simply be brought into the house by a draft.
- You can infect indoor flowers with a pest by buying a new plant in the store.
- Putting a bouquet of wild flowers in a vase, there is a possibility that pests were brought into the living space with them.
Control measures when found on houseplants
Warm and dry air stimulates the reproduction of harmful thrips indoors. Pests are able to infect growing plants in a short time.houseplants nearby. Before treating flowers affected by thrips, they must be:
- Isolate in a separate room, wash off adults and their larvae with warm water.
- If possible, remove the top layer of soil and fill it with a new one or transplant the plant, thoroughly washing its roots.
How to deal with thrips on plants, consider further.
To get rid of the pest at home, gentle ways to deal with thrips are more suitable. They are not capable of harming the plant. Their use is recommended when the first signs of infection are detected:
- A teaspoon of chopped onion or garlic is poured into a glass of water, insisted for a day, the plant is treated with the resulting product.
- Dried marigold flowers are placed in a liter jar and poured with boiling water. After a few days of infusion, the liquid is filtered and the plant is watered under the root.
- 50 g of fresh dandelion leaves are poured with a liter of warm water. After three hours, the infusion is filtered and the affected plants are sprayed with it.
- 100 g of chamomile is poured with a liter of water and infused for 10-12 hours. The finished composition is filtered, a little soap is added, the leaves and stem of the plant are wiped. A day later, the flower is rinsed with warm water.
- 50 g of flowering celandine is soaked for a day in a liter of water, after which the plant is treated with a ready-made infusion.
- 100 g of dry tobacco is infused in a liter of water for 24 hours, then filtered, another liter of water is added and the plant infected with thrips is sprayed.
In case of mass infection of plants, it is recommended to resort to the help of insecticides. They will destroy not only adults, but also delayed larvae:
- "Aktara". A broad-spectrum agent, it is used not only for processing the plant itself, but also for the soil. Effective at an early stage of infection.
- Fitoverm. A drug with good results in the fight against many types of pests. For processing, two ml of the product is enough, which is diluted with a glass of water.
- Aktellik. Highly effective insecticide that kills thrips quickly and easily. One ampoule of the product is dissolved in a liter of water, indoor plants are sprayed.
- Vermitek. A preparation that eliminates and permanently protects against the reappearance of pests. In a bucket of water, dilute two and a half ml of the product and treat the infected areas.
Processing of plants is carried out in the open air or in a well-ventilated area. After using any of the chemicals, the flower is covered with a plastic bag for a day. Re-treatment is carried out after 10 days.
Fighting in the garden
Thrips is a pest. To get rid of insects that affect horticultural crops, one of three methods of control is used:
- Chemical treatment. In any suburban department you can purchase one of the special preparations:"Karate", "Intavir", "Fitoverm", "Agravertin" and others. The agent is prepared according to the instructions, the crops and the soil under them are treated. Then covered with polyethylene for a day. If necessary, repeat the treatment.
- Biological method. This method involves the use of ticks specially propagated in the laboratory. Each of them is capable of destroying up to hundreds of thrips. This method is very effective and safe.
- Folk methods. Experienced gardeners recommend treating plants with an infusion of garlic or onions, as thrips cannot stand its smell. Another option is to put a container with crushed garlic or turpentine under the infected plant, cover everything with polyethylene.
To prevent thrips from breeding on orchids or other indoor plants, it is important to pay attention to the following recommendations:
- daily leaves and flower stems are inspected for thrips infestation;
- should not allow the soil of the plant to dry out, thereby creating favorable conditions for the reproduction of parasites;
- when buying a new flower in the first few days, it is placed in an isolated room and observed for signs of pest infestation;
- from time to time plants are treated with infusion of celandine or tobacco to get rid of uninvited guests.
These affordable rules will help prevent infection of indoor plants not only with thrips, but also with other diseases and pests.