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Thrips belong to the order of vesicles, the family of fringed insects.
A very common pest on indoor flowers. Moreover, if spider mites can selectively eat flowers, for example, they rarely touch Benjamin ficuses, then thrips is more omnivorous. It is especially harmful to flowering plants.
What an adult thrips looks like: the body is elongated, fusiform, segmented, in front of a pair of long antennae. But the size of thrips is small, about 1.5 mm. Such a trifle is found in our latitudes, but some species of thrips from tropical countries reach 1 cm or more. But not all of them are herbivores, the most bathing species Aelothrips, Scolothrips are predators, they eat small insects and ticks.
The name fringed arose because two pairs of wings in thrips are covered with fine, frequent hairs, like fringes. But you can see where the wings of a thrips can only be under a microscope - when it sits on a leaf, the wings are folded along the body and are invisible.
And the name bubble-legged comes from a special device - bubble-shaped suckers on the legs allow thrips to hold tenaciously on the leaves and not only fly, but jump briskly. Therefore, sometimes you can see thrips on a leaf, and after a second it jumped to the next one. Thrips are jumping like fleas - you can't catch them.
Therefore, if you bring beautiful bouquets of roses or peonies from the garden, know that you are probably carrying thrips home as well - they are very fond of peonies, hide in buds and petals, and thanks to their jumping ability, they will get from the vase on the table to the windowsill.
The mouth apparatus of thrips is piercing-sucking, very quickly the thrips sucks out all the juices from the plants. Much faster than ticks. From the mite on the leaf, the marbling is point punctures, and from the thrips there are small specks, often similar to strokes. But soon discolored silvery spots of irregular shape are formed along the leaf, gradually the leaves become entirely silvery, translucent.
In addition, thrips contaminate plant leaves with their secretions - shiny black drops and gray skins from molting.
Another difference between tick lesions and thrips: ticks are usually collected on the back side of leaves, where you can see husks from molts, then excrement and thrips skins lie on both the upper and lower sides of the leaves. But the pests themselves usually hide in the upper layers of the soil, in the axils of the leaves, the larvae in the buds and flowers that have not yet opened, and the eggs are laid directly in the parenchyma (tissue) of leaves, stems, buds, ovaries and fruits.
What is remarkable - on different flowers, thrips prefer to lay eggs and feed on different parts of plants - in some they lay larvae in flowers, less often in leaves, for example, on roses. And in other plants, both on leaves and flowers, for example, in orchids.
The bad news is that thrips can easily spread pathogens of fungal infections and viruses to plants.
Thrips development stages
- egg - 12-30 days, depending on temperature;
- larva - 1-2 weeks (at several ages), mobile, feeds on plant sap;
- pronymph - 1-3 days, has wing buds, does not feed;
- nymph - 2-3 weeks, there are wings, underdeveloped, fringe has not formed, cannot fly, does not feed;
- imago is a sexually mature individual, it flies, jumps, feeds, after molting, young females are inactive for the first 1-2 days.
The rate of thrips development depends on the temperature - the hotter the faster. So, at a temperature of about 15-16 degrees, eggs ripen for 14-30 days. At a temperature of about 28-30 degrees - 6-12 days. One female lays up to hundreds of eggs, according to some sources, up to 300 eggs. But Sims do not start laying eggs from the first day, but for 2-10 days, depending on the temperature.
There are many types of flower thrips, they differ in color and size. Males are usually smaller than females, the color is from yellow-brown to brown, almost black. The larvae are yellowish or gray, translucent, move quickly when the time for transformation into a pronympha is approaching, the larvae usually hide in the upper layers of the soil.
What you need to know about thrips
- Thrips are widespread in temperate climates, there are many different types of thrips in gardens, they can be brought home with garden flowers, bouquets, from a store with indoor flowers or cuttings.
- Thrips affects many indoor flowers: tradescantia, ficus, dracaena, dieffenbachia, monstera, palm trees, but especially loves saintpaulias, hibiscus, gardenias, orchids, citrus fruits and other flowering plants.
- One of the signs of defeat by thrips is the shedding of pollen - the larvae climb deep into the buds, gnaw out the anthers.
- Eggs and nymphs of thrips have protective covers, so contact insecticides do not take them. This means that treatments for thrips must be carried out in such a way as to destroy all newly hatched from eggs while they are in the larval phase, and of adults (adults).
- Calculate the frequency of treatments based on the ambient temperature.
- A hot shower is not able to cope with thrips, alas.
In the atlas of pests of indoor flowers, there is also a photo of thrips and the personal experience of forum participants on methods of combating thrips.
How to deal with thrips
Due to the fact that thrips leads a secretive lifestyle, and eggs and nymphs are not affected by contact preparations, then only the use of systemic insecticides is effective on flowering plants. This concerns, first of all, Saintpaulias.
Contact pesticides can be used on ornamental deciduous plants, as well as those flowering before bud formation, since larvae and adults are on the surface of the plant.
Of the systemic insecticides, the most effective against thrips are Actara and Confidor. Dilute Aktar at a concentration of 1 g per 2 liters of water. Usually, thorough watering is sufficient, the active substance is carried through the vascular system to all organs of the plant.
Often it is necessary to cut off the buds and flower stalks, but if the thrips has not yet had time to greatly spoil the flowers, when processing with Actara, you can do without removing the buds.
In addition, during the use of Actara at normal room temperature, i.e. from 20 degrees and above, the period of its protective action is 2 - 4 weeks, which means that nymphs hatched from eggs or molted will receive their dose of chemicals.
But the aktara practically does not come to the fruit. From a hygienic point of view, this is good, but it means that citrus and other fruit trees should be re-treated in time to ensure that pests are eliminated.
From contact drugs are effective:
- avermectins: Vermitic, Fitoverm,
- cypermethrins: Intavir, Iskra, Sharpey, Arrivo,
- neonicotinoids: Tanrek, Colorado, Golden Spark, Mospilan,
- organophosphorus compounds: Actellik, Karbofos and others.
Multiplicity of treatments with contact insecticides
If we proceed from an average room temperature of 22-26 degrees, then the time for the development of eggs and nymphs is 4-5 days, for 2-3 knocks the females lay eggs, therefore the period of re-processing is 5-8 days.
At a temperature from 15 to 22 degrees - repeated treatments within 8-16 days after the first.
If the flowers are on the balcony, where the average daily temperature is below 15 degrees, re-processing in 8-10 days, then the third in a week.
At a temperature of 28-30 degrees, the full development cycle from the egg to the breeding female is 5-7 days, it is better to re-process it on the 5th day after the first.
How to treat thrips insecticides
- Dilute the working solution according to the instructions.
- With solutions of contact-systemic preparations of Actara or Confidor, it is possible to water the soil in pots, for reliability it is possible to spray it.
Thoroughly spray all the leaves with solutions of contact action, or prepare the solution in a bucket of water and dip the plants upside down for 2 minutes. So the solution can penetrate better into the buds than when spraying and destroy the pest. But besides this, you need to thoroughly moisten the top layer of the earth with a solution.
You can dip flowering, but not the most capricious plants, for example, small hibiscus, Kalanchoe, spathiphyllum.
- It is not necessary to tie the sprayed plants into a bag, the main thing is to re-process them on time.
- But to thoroughly ventilate the room after the plants have dried is a must.
- It is advisable to carry out the treatments outdoors: arrange the plants in boxes and spray in a windless place.
- Thoroughly wash windowsills, glass, frames with soapy water.
Consumption rates of some insecticides from thrips
- Aktelik - 2 ml per 1 liter of water,
- Vertimek - 2.5 ml per 10 liters of water,
- Intavir - 1 tablet per 10 liters of water,
- Karbofos - 15 g per 2 liters of water,
- Karate - 1 ml for 5 liters of water,
- Confidor 1 g per 5 l of water,
- Mospilan - 0.5 g per 8 l of water,
- Fitoverm - 2 ml per 200 ml of water.