Western flower thrips - petty misfortune, but crop may disappear

Thrips or vesicular small insects settled throughout the continent. In nature, there are more than 6 thousand species. Insects specialize in plant nutrition, in most cases they choose crops. Western flower thrips belongs to quarantine objects. This is a harmful organism, the distribution of which must be limited. Insects damage 300 species of plants: vegetables, flowers, other ornamental crops in open ground and greenhouses.

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Western California flower thrips belongs to the thrips family, the genus Frankliniella. The body length of adults is 1-1.5 mm. Coloring is light yellow or brown. The body is narrow, smooth. The head is transverse. Antennae consist of 8 segments, labial palps of 3. The edge of the forehead is beveled to the mouth cone. The oral apparatus is a piercing-sucking type, characteristic of insects parasitizing on plants. The ovipositor of females is bent down.

The abdomen consists of 10 segments, on the eighth tergite scallop of denticles. The legs are shortened, running, a vesicular sucker at the end of the foot. 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 egg laying.

Insects have sexual dimorphism, the photo shows a large female of western flower thrips and a male inferior to her in size.

Distribution area

The pest's homeland is North America (California), it was in the place of the first fixation of flower thrips that its name was chosen. Along with imported plants, insects have spread around the world. Now they are found in Europe, Australia, Africa, are 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 seen in the greenhouses of Russia. A quarantine object is registered in several regions of the Russian Federation: Kursk, Ulyanovsk, Moscow, Kaliningrad and others.

Lifestyle

Detecting a pest makes it difficult for a secretive lifestyle. Western flower thrips is a typical polyphage; it feeds on 250 species of plants. Insects eat on pepper, tomatoes, cucumbers, peaches, lettuce. Often found in various colors - roses, cyclamens, gerberas, carnations. Adults suck juice from various organs of plants: leaves, stems, flowers and fruits.

The heat-loving species in the southern regions hibernates in open ground, but insects cannot withstand Russian frosts. Pests in the cold season wait in greenhouses. Imagoes hide in plant debris, and larvae burrow into the soil.

The spread of Western flower thrips occurs through the importation of infected seedlings of flower and vegetable crops, with fruits and ornamental plants. Directly into the greenhouse, it can fly into from a neighboring site, be recorded on a person’s clothes. Females often lay eggs in plant tissue. Outwardly, it is impossible to determine. Cutting off infected plants, you can bring pests to the house or greenhouse. In summer, thrips leave the greenhouses, spreading in the district.

Malware

What harm does western California thrips cause? Spending the whole life cycle on plants, insects damage cells by eating juice. Infected plants slow down in growth, lose leaves and flowers, the fruits are deformed. Crop yields are reduced. 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).

Thrips are carriers of various viral diseases. Crops weakened by the activity of the pest colony are defenseless against the spotted wilt virus. Despite the name, the disease affects 1,000 plant species, causing enormous economic damage.

Breeding

Western California flower thrips are an incomplete insect. In development, the following stages are replaced: egg, larva, nymph, pronymph, imago. After mating, females lay up to 100 eggs on stems, petals and leaves. The eggs are light, 0.2 mm in size, shaped like a bean. Ripening time depends on temperature. At + 25 ° the embryo is formed in 2-3 days, at + 15 ° the development is delayed for 11 days.

Information. Offspring are also born from unfertilized eggs. In this case, all the larvae are male.

The larva is light yellow, outwardly similar to adult individuals. Offspring usually hatch in groups; in one area, many small pests begin to drink plant juice. Larvae pass two ages, by the end of the second they cease to feed and turn into pronymphus, then nymph. At this stage, they descend into the soil. After 1-3, an imago appears. In favorable conditions, the full development of generation takes 12 days.

Information. During the year, 12-15 generations of western flower thrips are replaced in the greenhouse.

Ways to fight

It is quite difficult to destroy a small pest. In his homeland, he received a stable immunity to many chemicals. Adults and larvae prefer to hide in the buds, buds, scales of plants, which makes it difficult to apply insecticides to them. Glue traps in blue help detect California flower thrips. They are especially effective in flower growing complexes. Cutting often occurs here, disturbed insects fly out and fall into traps.

In the fight against the quarantine organism, a set of methods is used:

1. Biological. In closed ground, predatory mites Oriuslaevigatus, Neuseiuluscucumeris help to destroy pests. Plants are treated with biological agents effective against phytophages.
2. Chemical. The most effective pest control was a mixture of Akarin and Aktara in the proportion of 0.4%: 0.06%. You can apply insecticides one at a time. Maximum efficiency appears 7 days after treatment. Spraying with "Actellic", "Confidor" is recommended.
3. Agrotechnical. The pest appears in greenhouses, where the cultivation of vegetable and flower crops takes place all year round. For a successful struggle, one should abandon the sowing of green crops in the winter for one season. Good results are obtained by the destruction of plant debris in the offseason, the disinfection of soil and premises.

Tip. Do not place cut flowers near potted plants. With flowers, pests can get into the house.

Preventive measures:

• A ban has been introduced on the import and export of flowers and other plants without inspection and approval of the quarantine service.
• Timely inspection of crops grown in greenhouses. Hanging traps at doors, vents, on plants.
• When a pest is detected, plants are burned.
• Soil and work tools need to be disinfected.
• In and around greenhouses, weeds must be torn out and removed before the onset of winter.