Content
Thrips on roses pose a great danger, since the insects are very prolific and go through up to 15 development cycles per year. In addition, they lay eggs under the dense cuticle of the leaf, so treatment even with powerful insecticides does not always have an effect.
Description and photo of thrips on roses
Thrips are a group of insects that parasitize roses and other plants. The body is elongated, length 1-2 mm. The mouth is piercing-sucking, the legs are slender, adapted for running, with teeth. Insects have two pairs of narrow wings, they are fringed with barely noticeable veins. Despite the presence of wings, they fly poorly; some species only run on the surface.
The pest is prolific (up to 200 eggs) and produces up to 15 generations during one season
The development cycle is as follows:
- Adult females lay eggs on the tissue of a dense membrane - the cuticle of a rose leaf.
- After a few days, mobile larvae emerge from these eggs and immediately begin to feed on plant juices.
- After this, they fall to the ground and begin to pupate.
- Then the larvae emerge and the cycle repeats again.
What harm do they cause?
The infestation of roses by thrips has quite dangerous consequences:
- the bush stops developing;
- flowering stops completely or becomes very weak;
- the rose is vulnerable to fungal infections;
- the plant may die as a result of general weakening.
It is quite difficult to combat the pest due to the peculiarities of its development cycle on roses:
- At the first stage, thrips lay small, invisible eggs under the skin of the leaves. At this point, spraying is useless since the eggs are well protected.
- At the final stage of development, thrips burrow into the surface layer of soil, where they lay larvae. It turns out that the pests are again unavailable for treatment. The larvae do not feed at this moment, so the drugs do not affect them.
Thus, it is advisable to spray roses against thrips at the moment when they are directly on the flower (adult stage) or immediately after laying eggs. At the same time, one generation quickly replaces another, which also makes it difficult to fight insects.
Signs of defeat
Signs of an invasion are visible in photos of roses affected by thrips. The main symptoms include the following:
- darkening of the petals at the edges;
- the appearance of discolored spots on foliage and buds;
- the buds practically do not develop;
- flowers become less decorative;
- roses begin to suffer from fungal infections, even those bushes that have not previously suffered from them.
Reasons for appearance
Thrips are ubiquitous in almost all temperate regions
Insect larvae overwinter in the surface layer of soil under dry leaves, and in the spring they move to the surface, moving along young shoots and weeds.
After the foliage of the weeds becomes coarser, thrips move to the bushes, begin to feed on fresh leaves, and then appear in rose buds. Main causes of infection:
- Purchase of new seedlings. It is better to purchase plants from nurseries or other trusted suppliers. Insects can enter an area with contaminated soil.
- Also, neighboring plantings of roses that have already suffered from thrips can become a source of infection. In this case, you need to take preventative measures to protect healthy flowers.
Measures to combat thrips on roses
There are several fairly effective methods for controlling thrips on roses. It is necessary to use special preparations, you can also use home solutions (folk remedies). It will not be superfluous to take care of preventive measures.
Preparations for thrips on roses
To combat thrips on roses, chemicals and biological agents are used. The most effective insecticides include:
- “Conifidor Extra” is a systemic agent that penetrates through the vessels into all plant tissues. To prepare the solution, take 2 g of granules and dissolve them in 1 liter of water, then adjust to 10 liters. This volume is enough to process one hundred square meters.
- "Aktara" is a drug that is mainly used to prevent thrips invasion. To prepare a working solution, you need to dilute 8 g in 10 liters.
- "Actellik" is a contact insecticide that provides a protective effect for three weeks. It is useless to use it in summer, since at temperatures above +25 degrees it is not effective.
Biological insecticides also give good results:
- "Akarin" is a drug with enteric contact action. It is quite simple to prepare - you need to dilute one ampoule in 1 liter of water. Treatment of roses against thrips is carried out only in dry weather.
- "Fitoverm" is a biological preparation based on a fungus. It begins to act within the first two days. It is used sparingly - only 2 ml per 10 liters is enough. This volume is enough for one hundred plantings.
- "Aktofit" is one of the few insecticides that gives an effect even in hot weather. Consumption rate – 10 ml per 1 liter. This volume is enough for one large or two small bushes.
All bushes need to be sprayed, not just those that have pests. Otherwise, insects will move to untreated specimens.
Folk remedies for thrips on roses
Treatment of roses against thrips can also be done using folk remedies. Basically, herbal infusions and decoctions are used for these purposes:
- Garlic - place five pre-chopped cloves in 500 ml of boiling water and leave covered for 5-6 hours. Strain, bring to the original volume of 500 ml and spray the rose bushes.
- An infusion based on dandelion roots - take 50 g of dry rhizomes, pour a liter of warm but not scalding water and leave covered for 4 hours. Strain and begin processing for thrips.
- An infusion of flowers or leaves, stems of marigolds - 50 g of fresh (you can also take dried) raw materials per 1 liter of water at room temperature. Leave for three days and treat rose bushes against thrips.
- You can add flea shampoo to any of the solutions - 1 cap per 10 liters. The specific brand of the product does not matter.
Resistant varieties
To date, no rose varieties resistant to thrips have been developed. Therefore, gardeners are advised to choose those varieties that have stable immunity to various diseases and pests. These include the following:
- Pis;
- Rosarium Utersen;
- Flammentanz;
- Golden Celebration;
- Rosa Westerland;
- Nostalgia;
- Angela;
- Degenhard;
- Larisa and others.
Prevention
Coping with thrips is not easy, since the pest easily adapts to different conditions, it is prolific and goes through a rapid development cycle, changing up to 15 generations per year. Therefore, it is best to prevent the spread of insects than to deal with the consequences. Among the main preventive measures recommended by experienced gardeners are the following:
- Every autumn, remove all fallen leaves, pruned branches and other remains of roses, as well as weed dry weeds. All these residues must be removed and burned. They cannot be used as mulch.
- Water the soil with a solution of any of the described insecticides - this will destroy pests that have moved to the surface layer for the winter.
- In the spring, immediately after the snow melts, remove the mulch, loosen the surface layer of soil and carry out preventive treatment with any preparation.
- After the buds and leaves begin to bloom, repeat the treatment.
- Carefully weed the rose garden throughout the season. As additional prevention, you can use mulch - straw, sawdust and other natural materials.
- It is also recommended to regularly water the entire root zone and irrigate the bushes, since water literally washes away thrips. But you should not abuse this method, since increased moisture leads to the rapid spread of fungal diseases of roses.
Conclusion
Thrips on roses are a rather dangerous phenomenon, and the pests can easily spread to neighboring plantings. To combat them, chemicals are used, and folk remedies are used only as an additional measure.
