Thrips is a detachment of plant pests that numbers several thousand species. They differ in a peculiar structure: extremely small sizes (from 0.5 to 1.5 mm), an elongated body, two pairs of narrow fringed wings, not adapted for long flights.
Homeland flower thrips
California flower thrips belongs to the quarantine pests of ornamental plants, fruit and vegetable crops. This misfortune comes from North America, and the parasite was introduced to Europe in the 80s of the last century, when it was discovered in the greenhouses of Holland. At home, this insect is widely distributed along the western coast of the continent, which explains its other popular name - western flower thrips. Currently, this pest, due to its vitality and fertility, has spread throughout all continents. Discovered in the early 90s in St. Petersburg, flower thrips have not yet been able to capture the entire territory of Russia, but has already been noticed in many areas.
Features of nutrition and living conditions
The spectrum of plant damage by California flower thrips is very wide. The pest is almost omnivorous and damages hundreds of species of flower, fruit and vegetable crops. These are cucumbers, tomatoes, peppers, cotton, alfalfa, grapes, strawberries, fruit trees, roses, gerberas, cloves, cyclamens. It feeds on flower thrips with plant cell juice, 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, fruit crops are declining in fruit crops, while the appearance of decorative crops is greatly affected. Yellow dots appear on the leaves due to dead cells and a black scattering of excrement, flower buds are not deformed and do not open, the fruits are not tied. The most numerous colonies of the parasite are able to completely destroy the crop. This insect also carries viral diseases that are dangerous to plants. Flower thrips are not harmful to humans - only economic damage. However, this damage can amount to millions of rubles!
Californian flower thrips is a thermophilic insect and feels great at a temperature of 15-30 ° C. If the temperature drops below 9 ° C, the parasite stops multiplying and hibernates, and if it rises to 35 ° C, its development stops. In open ground in a temperate climate of the middle zone, California thrips are not able to overwinter, but it is considered to be the most dangerous pest of closed ground. Greenhouses are an environment especially favorable for an insect, with the most suitable temperature regime for its propagation, and also independent of climatic zones. In large greenhouse farms, it is problematic to completely destroy this parasite. In the best case, it is possible to keep the number of its colonies at a certain level, and then the damage will not be so significant. The severity threshold is calculated for each culture separately.
Breeding
In one year, under suitable conditions, 15-20 generations of the pest are capable of succeeding each other. In just 4-5 days, the population of flower thrips can double. The life span of one insect is 1.5-2 months. Females pierce various parts of plants and during the month lays an average of about 100 in them, and a maximum of about 300 eggs. After a few days, a larva emerges from the egg, which is a reduced copy of an adult individual, only without wings, and only two weeks later, the next generation insect is ready for breeding.
Control measures
The main method of dealing with such a pest as flower thrips is preventive measures in the form of quarantine measures. It is necessary to check for infection all plant products: planting material, cuttings, potted plants, cuts of flowers. The easiest way to deal with flower thrips is in the offseason, when you can remove plants and soil and greenhouses.
I must say that highly toxic pesticides are not only environmentally hazardous, but in the case of this pest are also useless. He has a fairly high resistance to them, and he leads a flower thrips secretive lifestyle, hiding in the buds, buds, under the scales of plants, thereby becoming invulnerable to chemical treatments. The biological method is considered the most effective: against flower thrips, its enemies are released: predatory bugs and ticks.