Enemies in our garden plants are many. These are pests that damage the underground parts of plants and those that damage the stems, leaves, fruits. One of the malicious ones is thrips. See the photo below. These are very small insects, it is very difficult to notice them on time. More often, we, gardeners, first notice the traces of their activities, and then we already think what kind of struggle with them will be effective. Thrips can harm all plants. And garden, and vegetable, and flower, and weeds. Fighting thrips, if they are already wound up in your garden, is necessary at all stages of plant development. And even the period of winter storage of planting material, when it comes to bulbous and tuberous flowers, is not the time to forget about them.
Without knowledge of biology and the pest development cycle, one cannot do here.
What does thrips look like on plants
Thrips (Thysanoptera), or Fringed-winged, Bubble-footed, is a large detachment of insects, including about 4.5 thousand species (we have at least 200). The unit received the name “fringed-winged” due to wings bordered by dense fringe of long hairs. And they are called “bubbly” because of the special vesicular formations on the legs, which act as suction cups.
As a rule, thrips are very small, subtle insects. The sizes of the adult individual (imago) of most species do not exceed 5 mm. Often males are winged, and females are wingless. All thrips go through five stages of development: eggs, larvae, pronymphs, nymphs and adults.
Thrips begin to show activity as soon as the air temperature rises just above 8C. With a decrease in temperature, insects become numb, do not feed and do not breed. And with an increase, conditions are created for laying eggs (20-40 pcs.) In plant tissue. A few days later, larvae of the first age emerge from the eggs. At first they are white, then they acquire a yellow-brown color. Developing, the larva passes into the pronimph stage, which after a few days turns into a nymph having the rudiments of wings. At the final stage of development, the nymph turns into an adult in black and brown, with a length of not more than 1-1.5 mm. The entire development cycle takes 2-3 weeks, depending on the air temperature. During the growing season, 7-8 manage to develop, and in the south we have even more generations of the insect.
Thrips is harmful to plants at almost all stages of its development. Only at the pronimph stage do they not feed.
The mouth apparatus of thrips is a piercing-sucking type. They feed on the sap of plants, first on the stems and leaves, and when inflorescences are formed, they seriously damage the developing buds and flowers. Externally, thrips lesions look like numerous discolored dots, specks, strokes.
In addition to visible damage, the harmfulness of thrips (as well as other sucking insects) lies in the fact that they spread infectious diseases, including viral ones.
In autumn, when the air temperature drops, thrips are gradually localized in the lower part of the stem and in the axils of the leaves, from where they move to the soil. Some thrips remain to winter in the soil on plant debris.
Fighting thrips on cucumbers, tomatoes and other plants
The fight against thrips must be carried out comprehensively, using both agrotechnical and chemical, as well as biological methods of plant protection. Success is possible only with their combination.
Agri-technical struggle with thrips
Specialists advise observing crop rotation. That is, if you noticed thrips on any plant this season, it’s best not to plant those that can be thripsy for 3-4 years. Most often, this requirement in the conditions of our limited garden plots is not feasible.
But advice will be relevant, to maintain the soil at a high phytosanitary level. That is, in the garden plot you need to regularly loosen the soil, weed out, burn post-harvest plant debris (tops). In this case, the main number of thrips remains on the leaves and stems of plants and does not have time to move to the soil.
Chemical methods of thrips control
Perhaps the chemical method of controlling thrips is the main one. However, it has some features due to the biology of insects. In particular, at some stages of development, the pest is invulnerable to pesticides. So, insect eggs laid in the tissue of the leaves and stem are practically inaccessible to the action of the preparations. In addition, with the systematic use of certain insecticides, thrips develops high resistance to their action, which is inherited by the next generation. The result is a new pest population with high resistance to chemicals.
But this does not mean that the fight against thrips is doomed to failure. Here are some tips to help gardeners and gardeners protect their site from pests.
When choosing insecticides to control thrips, be guided not by the trade or technical name of the drug, but by the name of its active substance. The fact is that on the basis of one and the same active substance often is created not one, but many drugs with different names. For example, Prestige, Matador, Masterpiece, Confidor are drugs, one of the active ingredients of which is imidacloprid. Sometimes the active substance itself has several names, for example, the name "imidacloprid" has synonyms - the admin and the gaucho. Finished preparations may differ in the concentration of the active substance, formulation, type of adhesive, but their mechanism of action and spectrum of application are the same.
Vegetative plants are better treated with systemic, rather than contact, insecticides - the effect will be more noticeable.
Observe the alternation of drugs with different active ingredients and, accordingly, a different mechanism of action on the pest.
Biological control methods
Given the growing interest in environmentally friendly technologies, the biological method of plant protection, it should be noted that there is no integrated system of plant biosecurity against pests, but its individual elements have been tested in practice and are effective.
In particular, to control the pest during spring processing of planting material (bulbs, root crops), you can use an aqueous infusion of garlic, and for spraying use mustard powder.
Very promising soil treatment with Metarizin.
This is a triple action biological product - biological fertilizer, plant stimulant, insecticide. It is created on the basis of a microscopic fungus. Metarhizium anisopliae, discovered about 100 years ago by I.I. Mechnikov. When introduced into the soil, the fungus multiplies, infects soil-borne insects (bear, horsetail, wireworms, thrips, scoops) and, parasitizing on them, causes the death of pests. Important and quite a long period of action of this drug is 2-4 years. The biological product is completely harmless to humans, animals, bees, birds, earthworms, frogs, toads, mice, and snakes.
Thrips drugs
There are a lot of drugs that will help you in the fight against thrips. All of them are difficult to list, and not necessary. The manufacturer often gives drugs with the same active substance different names. How to figure it out ... Therefore, the most important thing in choosing, as mentioned above, you should pay attention to the active substance when buying. You will process plants more than once. Alas, this is so, otherwise we will not be able to cope with such a pest. In order not to cause addiction of thrips to the same active substance, it is necessary to alternate preparations containing them. Buy drugs with different active ingredients and alternate them.
We grouped the preparations according to the active substances, so that it would be easier to understand, and the choice is yours.
- Imidacloprid. The following preparations containing it are on sale - Confidant, Bison, Spark, Biotlin, Commander, Confidor. It is advisable to treat the plants with these drugs before flowering. You can not treat these plants grown on herbs with these drugs. For example, all kinds of salads, dill, parsley, onions on greens, early cabbage, leaf celery, spinach, sorrel.
- Diamethoxam. It contains Aktara, Tiara. Acts through direct contact or the digestive system. Differs in speed of impact. Aphids are affected after an average of 15 minutes. Other insects stop feeding one hour after spraying. Danger to bees.
- Cypermethrin. It is included as the main active ingredient in the following preparations: Inta-Vir, Alatar, Spark, Shar Pei, Confidelin. A significant drawback of cypermethrinodine - the insecticide does not affect insect eggs, so the treatment should be repeated twice more - every 5-10 days. Try not to process plants during flowering.
Of course, there are many more drugs for thrips than those listed above. Our task is to give a general idea of thrips, their lifestyle, methods of struggle. And also to orient you, what should be guided by when choosing drugs to combat thrips.