Flower Californian thrips refers to quarantine pests of ornamental plants, fruit and vegetable and vegetable crops. It comes from North America, and the parasite was introduced to Europe in the 1980s, when it was discovered in greenhouses in Holland. At home, this insect is widely distributed along the west coast of the continent, which explains another of its popular name - the western flower thrips. Currently, this pest has already spread to all continents due to its vitality and fertility. Discovered at the beginning of the 90s in St. Petersburg, I didn’t manage to capture the entire territory of Russian flower trips, but in many areas it was already noticed.
Appearance and general characteristics
This pest is on the first lines in the lists of insect parasites that are confronted by specialists of the Department of Quarantine in crop production. There are thrips larvae in both foodstuffs and flowers intended for sale, that is, in considerable quantities..
Homeland California pest America, its North and Central parts, where the presence of thrips everywhere, from the Mexican territories to the coast of Alaska. The name was due to the first place of detection, that is, California. However, local scientists suggest that thrips were brought by accident with flower crops from some South American country. In Europe, it was recorded in 1983. Since that time, the insect has captured the entire European continent, and since the 90s it has been found in Russia.
Adult copy up to 2 mm, with a narrow yellow-headed torso. The body itself may be light, yellowish or brown, saturated. On the wings darkened areas. The larval form is similar to sexually mature, but smaller and lighter in color.
Prefers to hibernate California thrips in greenhouse conditions. Adult insects hide under plant waste, and the larvae invade the soil. In southern regions can winter in open field. Activated after planting seedlings.
The female makes egg laying in leaves, in specially gnawed holes or at the top of the stem. During the month, lays up to 30 dozen eggs. When pollen is fed the clutch grows. After hatching, the larva goes through two cycles of development on the plant itself, feeding on it, and on the third it goes into the soil. The total development time from egg to adult pest is 2.5-3 weeks. Under good conditions, up to 15 generations take place in a year.
Western pest is a “specialist” of a wide profile. Cucumbers, peach and other fruit trees, grape plantations, onions, tomato ridges, planting peppers and strawberries fall into his field of activity. And many other plants, in total more than 250 species. As well as flower cultures: rose bushes, gerberas, cyclamen, chrysanthemums, etc. In the food is juice, which is sucked by the larvae and adult insects.
Danger and harm to the plant
The first thing that emerges from the vital activity of flower thrips is the yellow spot and roughness on the leaves. Over time, the lesions grow and the spots merge, and the leaf dries and dies.
During mass attacks, the stems become bent, young shoots are deformed, grow poorly, and entire areas of damaged plants are visible. When feeding on flower buds, the color is twisted, the bud is not opened and it dries.. When pollen nutrition stops the formation of flowers. As a result, the yield drops sharply, the presentation is lost, the cost decreases.
With the defeat of fruit crops, the picture is no better. Silvery stripes are formed on fruits and berries, the color, shape, deformation occurs and holes appear. Thrips spreads a very dangerous disease to tomatoes - spotty wilting. The main symptoms of the virus are yellow spots, dark patches on the stems. To transmit the infection to the culture, it is enough to tryps to suck the juice out of it for half an hour.
Nuances and difficulties in the fight
Extermination of thrips causes difficulties even with the use of pesticides:
1. It is difficult to achieve direct contact between the insecticide and the pest, since insects hide in parts of plants (bud, flower, stem, bark, scales).
2. Immunity to many chemicals, which thrips has developed in the homeland of its habitat, in America. For greenhouses (the most common) thrips there are no tools that can be combined to combat other parasitic insects.
Ways to combat Californian flower thrips:
Mechanical. Shelter plants potential victims fine-meshed mesh. It is installed on the window, door openings, ventilation grilles.
Agrotechnical. Constant monitoring, removal of affected plants, regular weeding, traps.
Biological. Settling the soil with special types of mites and bedbugs. They do not get rid of the pest at all, but it will greatly reduce its livestock. Moreover, biological destroyers are eaten not only by the larvae, but also by adult thrips.
Chemical. With the help of several chemicals specifically designed to combat small pests. These drugs are very high toxicity, are used two, at least three times with intervals of several days.
Although the destruction of thrips is difficult and not always successful, but it is necessary to fight it. Who, except for you, will protect your green landings from the invasion of an insidious, voracious and prolific "immigrant" from the West.
The main elements of the integrated system of plant protection from Western flower thrips can also be attributed to:
Mechanical protection. The culture threatened by thrips is covered with the lightest mesh with a cell size of 192 (m [1 (m = 10-6 cm). Doors and other openings are closed with the same mesh. The effectiveness of this technique reaches 30-70%.
Traps (blue) should be posted to identify the pest in the early stages of settlement and possibly prevent its spread. For every 50 m 2 one trap is hung out. For mass capture of thrips, it is necessary to set 1 trap per 10 m 2. If in greenhouses, thrips have already spread, the control with the help of traps allows us to estimate the level of occupancy and the degree of potential harmfulness. The predominance of trapped males indicates a low level of population density. During this period, it is still possible to prevent the outbreak of reproduction. The predominance of females - indicates the outbreak has begun and the need to take urgent destructive measures.
The density of populations can be reduced to some extent, manipulating temperature and humidity in the greenhouse. This technique is especially effective at the end of the growing season, at which time an increase in air temperature of 40 ° C and higher for 24 hours while reducing humidity helps clean the greenhouse from pests.
Biological method. Tick release rates depend on the crop to be protected and plant pest density. They can be several ticks per sheet, several dozen individuals per square meter of greenhouse, several hundreds per plant.
It is necessary to take into account that predatory mites destroy only larvae and do not feed on adults.
The rate of release of bedbugs is very low, for release from thrips per cucumber plant it is enough to release 1-2 adult bugs. Good effect gives the combined use of mites and bedbugs.
Excellent results in the fight against thrips showed the drug Venevia or its complete analogue Excilrel.
Practically on seedling cultures, this insecticide together with the adhesive is used 10 days after transplanting, and then 10 days after the first treatment.
A prospective insecticide Mowento is currently being registered. In 2015, was successfully tested in the fight against ticks.
As practice shows, in order to reduce the risk of diseases and pests of cucumbers and to maintain plants in a healthy state, it is necessary to observe a number of preventive measures. Choose seeds of varieties and hybrids that are resistant to a number of major diseases. Before sowing, be sure to seed dressing. Follow the rules of watering. Feed plants with quality. Timely respond to the first signs of crop damage by diseases and pests. Remove affected plant parts. Fight weeds. After the end of the growing season, carefully remove plant residues from the greenhouse.
Nutrition and living conditions
The spectrum of plant damage by flower Californian thrips is very wide. The pest is almost omnivorous and damages hundreds of species of flower, fruit, and vegetable crops. These are cucumbers, tomato, peppers, cotton, alfalfa, grapes, strawberries, fruit trees, roses, gerberas, cloves, cyclamens. Flower thrips feed on plant cell sap, which, thanks to the piercing-sucking mouth apparatus, is extracted from stems, leaves and fruits, as well as nectar and pollen in buds. As a result, the yield of fruit crops decreases, while the appearance of ornamental plants suffers greatly. Yellow dots appear on the leaves due to dead cells and black scattering of excrement, flower buds are deformed and do not bloom, fruits are not tied. The most numerous colonies of the parasite are able to completely destroy the crop. This insect also carries dangerous viral diseases for plants. Flower thrips does not cause harm to a person - only economic damage. However, this damage can amount to millions of rubles!
Flower Californian thrips - a heat-loving insect and feels great at a temperature of 15-30º C. If the temperature drops below 9º C, the parasite multiplies stops and hibernates, and if it rises to 35 º C - its development stops. In the open ground in the temperate climate of the middle zone, Californian thrips are not able to winter, but it is considered the most dangerous pest of greenhouse. Greenhouses are a particularly fertile environment for insects, with the temperature regime most suitable for its reproduction, and, moreover, independent of climatic zones. In large greenhouses, it is problematic to completely destroy this parasite. At best, it is possible to keep the number of its colonies at a certain level, and then the damage will not be so significant. The threshold of harmfulness is calculated for each culture separately.
In one year, under suitable conditions, they can replace each other 15-20 generations of the pest. In just 4-5 days, the population of flower thrips can double. The lifetime of one insect is 1.5-2 months. Females pierce various parts of plants and in a month lay an average of about 100 in them, and as much as possible - about 300 eggs. After a few days, the larva emerges from the egg, which is a reduced copy of an adult individual, but without wings, and after only two weeks the next generation insect is ready for reproduction.
The main method of dealing with such a pest as flower trips is preventive measures in the form of quarantine measures. It is necessary to check for infection of all plant products: planting material, cuttings, potted plants, flower sections. The easiest way to deal with flower thrips in the offseason, when you can remove the plants, carry out the treatment of soil and greenhouses.
I must say that highly toxic pesticides are not only environmentally dangerous, but in the case of this pest they are also useless. It possesses a fairly high resistance to them, and the floral trips lead a secretive lifestyle, hiding in the buds, buds, under the scales of plants, thereby becoming invulnerable to chemical treatments. The most effective is considered a biological method: against the flower thrips let out his enemies: predatory bugs and ticks.
Description of the species
Western California flower thrips belongs to the family of thrips, genus Frankliniella. Imago body length is 1-1.5 mm. Color is light yellow or brown. The body is narrow, smooth. Head transverse. Antennae consist of 8 segments, labial palpi - of 3. The edge of the forehead is sloping towards the mouth cone. Mouth apparatus piercing-sucking type, characteristic of insects, parasitic on plants. Females ovipositor fold down.
Male and female thrips
The abdomen consists of 10 segments, on the eighth tergite a comb of cloves. The legs are short, running, at the end of the foot is a bubble sucker. Insects have a pair of narrow long wings, pointed at the tips. Along the edge they are framed by cilia. The special structure of the wings allows thrips to fly from one plant to another in search of food and during the laying of eggs.
Insects present sexual dimorphism, the photo shows a large female of Western flower thrips and a male, inferior to her in size.
The homeland of the pest is North America (California); its name was chosen precisely at the place of the first fixation of flower thrips. Together with imported plants, insects have spread throughout the world. Now they are found in Europe, Australia, Africa, seen in the vast territory of Asia. In Europe, the pest appeared in 1983, in a record short time, spread to all countries. In the early 90s, western flower thrips were spotted in greenhouses in Russia. The quarantine object is registered in several regions of the Russian Federation: Kursk, Ulyanovsk, Moscow, Kaliningrad and others.
Pest on a cucumber leaf
Detecting a pest makes it more difficult to steal a lifestyle. Western flower thrips are a typical polyphage, it feeds on 250 species of plants. Insects feed on peppers, tomatoes, cucumbers, peaches, lettuce. Often found on various colors - roses, cyclamen, gerberas, carnations. Imago suck the juice from various organs of plants: leaves, stems, flowers and fruits.
The heat-loving species in the southern regions winters in open ground, but insects do not survive the Russian frosts. Pests in the cold period are waiting in greenhouses. The imago hides in plant debris, and the larvae burrow into the soil.
Thrips on rose bud
The spread of Western flower thrips occurs by importing infected seedlings of flower and vegetable crops, with fruits and ornamental plants. Directly into the greenhouse, it can fly into it from a neighboring site, be carried on a person’s clothing. Females often lay eggs in plant tissue. Externally, they can not be determined. Cutting off infected plants, you can bring pests into the house or greenhouse. In the summer, thrips leave greenhouses, spreading around.
Cucumber Leaves Damaged by Californian Flower Thrips
What harm does western Californian trips cause to humans? Carrying out the entire life cycle on plants, insects damage cells, feeding on sap. Infected plants slow down in growth, lose leaves and flowers, the fruits are deformed. Reduced crop yields. The main sign of the presence of a pest on plants is the appearance of dry light spots and black dots on green leaves (accumulation of thrips excrement).
Consequences of damage to indoor plants with thrips
Thrips are carriers of various viral diseases. Cultures weakened by the life of the pest colony are exposed to the spotted wilt virus. Despite the name, the disease affects 1000 species of plants, causing enormous economic damage.
Threat to the cottage
California thrips can live in unheated greenhouses during the season.Either forms foci on crops such as onions and cabbage. It can develop on them in the summer, and then come to them in storage. At +10 ° C, it begins to feed, and at +13 it multiplies again. And if onions or cabbage are left till spring, then with them he can again get into the open ground and proceed to malicious activity on the site.
Alas, ordinary people can bring Californian thrips to their dacha, bringing back cabbage or onions bought at the store. Then the pest can cause them a lot of trouble: it is able to completely destroy the cucumbers in the greenhouse and destroy all the flowers - their leaves and petals will be covered with spots, and then they will die. Among other things, thrips carry viruses (some of them spread only with these insects). Among them, one of the most dangerous viral diseases of tomatoes is the bronze of tomatoes, which has already appeared in the Moscow region. When Californian thrips came to Bulgaria (in this country, tomatoes are in the status of a strategic culture), it caused great damage by the fact that it brought with it the tomato bronze virus.
Pest and potted flowers
California thrips harms most on production sites. And although no one is immune from the fact that the thrips brought home will be transferred to indoor plants, but he will not live on them for long. So home flowers are more likely to suffer from the relatives of our hero.
If you cut a cabbage head or onion and you see something dark inside (and the wintering individuals are usually like that), which also ran, - most likely it is thrips. By the way, not necessarily Californian: there may be another kind, but this is no easier. At temperatures above +13 ° C, pests can also be detected on the surface. It is better not to try to eat such vegetables as there are usually plenty of insects inside. It is possible that the leaves are already full of eggs. If in warm weather you just throw away the spoiled food in the dacha compost, then thrips can fly out of them, which will pounce on your garden. Contact of infected objects with any living plants is especially dangerous.
So food or flowers with thrips should be immediately destroyed. The apartment is more convenient to use boiling water. But at the dacha the easiest way to bury an unsuccessful purchase in the ground. Putting 10 cm of soil on top of it, you can be calm - thrips will not get out.
Description of the adult
Adult thrips have a narrow oval body, the length of which is approximately 0.8–0.9 mm. It has two pairs of narrow wings of gray-yellow color, surrounded by fringe. Females and males have some differences.
The female can be both light yellow and dark, almost black, brown. It has a transverse head with small bristles and a transverse prothorax. The front wings have a slightly yellowish tint, and the lower legs and thighs are gray. The male is smaller than the female, about 0.1–0.3 mm. Antennae are darker, and the body, on the contrary, is lighter.
It differs from other types of thrips tobacco in that it has four distal setae on the front wings and a practically transparent first antennal segment.
Subspecies of tobacco thrips differ in body color. In the spring usually meet dark, and in the summer light.
In the winter, females go to the soil or plant debris to a depth of 5–7 cm and leave in the middle or end of April, settling weeds. In the leaf tissue they lay eggs, about 100 pieces for a life. Fertility depends on the type of forage plant and temperature. The most intensive development occurs in dry places.
Tobacco thrips are almost never found on young or aging leaves. The most part is located on the formed. Larvae are found on the lower part of the leaf, less often - on flowers or fruits.
The embryo develops from three days to a week, then the larva stage passes for about 10 days. They go to the soil. And about a week later, adult insects are already rising to the surface.
Females and their descendants fly from weeds to crops and cause damage.
What harm does plants do?
Tobacco thrips harm the onions, cucumbers, zucchini, eggplant, melons and sometimes cabbage, celery and parsley. Damage is caused both to the larvae and adults.
The tobacco thrips sucks the juice from the leaves, which leads to a deficit of moisture and the formation of yellow-brown spots. Also damaged petals and stamens. When insects are very dense, leaves curl, turn yellow and dry up completely. In addition, thrips can eat the sap of flowers, because of which they fall prematurely.
To get rid of the Swedish fly, you can use various methods of struggle - both chemical and folk. Detailed information you will find in this article.
Pea seed larvae are about 6 mm in size. For a full description of the insect, see http://stopvreditel.ru/rastenij/selxoz/gorohovaja-zernovka.html link.
- providing high humidity and uniform watering, since tobacco trips mainly develops on those crops that grow in dry places,
- digging up the soil and eliminating post-harvest residues,
- weed control, because thrips multiply and feed on them in spring,
- placing onions as far as possible from other crops to prevent them from becoming tobacco trips, since the onions most often damage the pest.
Insecticides are used at intervals of a week. Can not be used on the onions grown on greens. The following remedies are effective:
- Aktara, VDG (400 g / ha),
- Karate Zeon, MKS (150–200 ml / ha),
- "Fufanon" (1 ampoule per 1 liter of water),
- "Commander Maxi" (3 g / ha),
- “Spark Gold” (10 ml / ha).
You can also use an infusion of onion peel - 4 liters of water for 2 liters of husk, after two days add another 12 liters of water and add laundry soap. And the bulbs should be treated with sulfur gas before storage (50 g of sulfur are used per 1 m3 of room).
The use of these methods (individually or in aggregate) will help rid tobacco and vegetable crops from tobacco thrips, and the use of uninfected planting materials will reduce the risk of its occurrence in the future.
Ways to fight
Destroying a minor pest is quite difficult. In his homeland, he received sustained immunity to many chemicals. Adults and larvae prefer to hide in the buds, buds, scales of plants, which makes it difficult for them to use insecticides. Glue traps of blue color help to find out the Californian flower trips. They are especially effective in complexes for growing flowers. Cutting often occurs here, disturbed insects fly out and fall into traps.
In the fight against the quarantine organism, a complex of methods is used:
- Biological. In a closed ground, predatory mites Oriuslaevigatus, Neuseiuluscucumeris help to destroy pests. Plants are processed with biological preparations effective against phytophages.
- Chemical. The most effective remedy against pests was a mixture of drugs "Akarin" and "Aktara" in a proportion of 0.4%: 0.06%. You can apply insecticides one by one. Maximum effectiveness appears 7 days after treatment. Recommended spraying "Aktellik", "Confidor".
- Agrotechnical. The pest appears in greenhouses, where the cultivation of vegetable and flower crops occurs all year round. For a successful struggle, it is necessary to abandon the sowing of green crops in winter for one season. Good results are obtained by the destruction of plant residues in the offseason, disinfection of soil and premises.
Council It is not necessary to place cut flowers near potted plants. With flowers in the house can get pests.
- A ban on the import and export of flowers and other plants without checking and approving the quarantine service.
- Timely inspection of crops grown in greenhouses. Hanging traps at doors, air vents, on plants.
- When a pest is detected, the plants are burned.
- The soil and working tools need to be disinfected.
- Inside and around greenhouses it is necessary to pluck weeds and remove them before the onset of winter.
Who are they?
Thrips are small and unusually voracious insects. More than two thousand species of this pest are known, and there are about 300 of them only in the territory of the former USSR.
Thrips are small oblong bugs of gray, drilling or black color. Depending on what type they belong to, their growth can be from 0.5 mm to 1.5 cm. Most often thrips are about 2 mm long. They have short, quick legs, each of which has a bubble-like growth at the very base. Because of this, they are often called bubbling.
They also have wings with several longitudinal ribs, along the edges of which there is a long hair fringe. During development, thrips overcome several stages, starting from the egg and ending with the imago. At that time, when thrips are larvae, they lack wings, and their color is beige or gray.
Species and their photos
Because of the small size of these insects, it becomes quite difficult to determine which species they belong to. Among thrips there are many different species that are extremely dangerous for various plants. Thrips dehydrate flowers, fruits and leaves, pollute plants with their secretionsand can also infect them with various diseases and viruses.
This species is one of the most common among thrips, which is also called "ordinary." It occurs everywhere, even in the subantarctic. Has a brown or black-brown color. The adult individual in length reaches no more than 1 mm. It has yellow fore shins and darkened wings, on the basis of which there is a light transverse strip.
During the year, give no more than 2-3 generations. Females lay eggs in sepals and fodder stalks. It carries considerable harm to the berry crop, grass, fruit trees, legumes and cereals. It feeds not only inflorescences, but also emerging ovaries. In total, there are about 500 species of various plants that feed on this pest.
Western Californian Floral
This pest belongs to tropical species. It is distributed throughout the world, but most of all in North America. It is a tiny insect, no more than 2 mm in length. It has a predominantly light yellow or dark brown color.
His mouth apparatus is piercing-sucking type. The front wings of this insect have a pointed top. Also This pest is highly resistant to chemical plant protection products.
It feeds on the juice of the cultivated crop, which leads to the curvature of fruits and shoots, deformation of flowers and delayed development of plants. Flower thrips also carry viral diseases..
This type of pest is widely distributed in Russia. In addition, it also covers the territories of North America, Africa and Western Europe. Wheat thrips is a small, elongated insect from 1.5 to 2.3 mm.
The oral apparatus, which is piercing-sucking type, is directed backwards along the body. The wings have an elongated shape, with a long fringe of cilia along the edges and narrowed in the middle. Cilia are also present on the posterior margin of the forewings. The color of this insect varies from black and drilling to black. The front legs and fore tibia of wheat thrips are colored yellow.
This species mainly damages the following plants:
- spring wheat,
- wild cereals,
- wild herbaceous plants.
When eaten, it damages flower films, corn scales and awns. It also sucks the juice, which causes the plants to be smooth and white-boned.
Tobacco trips are most common in Australia, America, Asia and Africa. It has an elongated oval-shaped body, which consists of separate sections of the abdomen, chest and head.
This species is rather small, unlike the others. Its maximum length is 1.5 mm. The forelegs and wings are yellowish in color. From other types of thrips it differs by the presence of lateral setae on each side of tergite of the second segment.
Mostly tobacco trips damage shoots, buds and leaves of plants from the following families:
But most often it harms tobacco by sucking the fluid from the cells of the epithelial tissue. In case of severe damage, the leaves of the plants are covered with yellow-white specks with black dots, after which they turn brown and dry.
It is a common vegetable pest. It is found throughout the world. The adult individual of this insect reaches in length from 0.8 to 0.9 mm. Onion thrips have an oblong narrow body, which is painted in a dark brown or light yellow color.
The wings of this insect are framed by a fringe. Damages the following crops:
Mostly damage is caused by females and larvae. They feed on the cell sap of the leaves, which causes the appearance of bright necrotic spots, which eventually turn brown. As a result of the damage caused, the plants slow down in growth and the yield decreases.
Rosan thrips are fairly widespread in the former USSR. It has an elongated oval body, which grows no more than 1 mm in length. Outwardly, it is not much different from raznoyadny thrips, with the exception of the characteristic brown color.
This species feeds on leaves and flowers, which belong to the Rosaceae family. Sucking the sap from the plants, it causes the appearance of brown spots on the leaves, after which they dry out. They settle inside the buds and therefore they are very difficult to detect.
This type of insect is most commonly found in North America and Western Europe, but is also widely distributed in Russia. Dratsenovy thrips has a small body, oblong. In appearance, it is similar to rosy and raznoyadny thrips. Its characteristic difference is the yellow-brown color.
Dracene thrips are extremely dangerous for many indoor plants, but more often it damages the following:
It is quite difficult to detect and is mainly distributed in enclosed spaces, especially in the northern regions.
This is the most dangerous pest of closed ground. Most common in the northern regions and the middle zone of Europe and Asia. He, like other representatives of thrips, has an elongated body ranging in size from 1.5 to 2 mm.
It can be distinguished from other species by a bright dark brown color. Also, its hallmark is dark wings, at the base and on the tips of which you can see bright spots. Decorative thrips are a threat to many indoor plants.
The following are particularly affected by it:
- Orchid (how to deal with thrips on the orchid, read here),
- Money Tree,
- palm trees.
Most often they live in flower buds. If the plant does not have flowers, then they stick to the lower leaflets.