Photos and symptoms of spider mites on raspberries
Spider mites are arachnid insects with a body length of no more than 0.7 mm. In nature, there are several types of pests, they differ in color. Most often, raspberries are affected by brown mites. But there are insects that are yellowish, green, and even milky in color. It is impossible to see microscopic insects on a plant, but an infestation of a bush can be determined by the following signs:
- a dense web that gradually covers the entire above-ground part;
- brownish or light spots on the underside of the leaves, gradually moving to the upper part;
- curling of young leaves;
- drying of buds.
Important! The appearance of signs of infection on the trunk indicates strong reproduction of the insect.
Prevention is the best cure
It is necessary to prevent the appearance of spider mites in order to protect seedlings from pests. All bushes should be regularly inspected and checked for young ticks.
It is also recommended to periodically treat the berries with biological products and folk remedies.
Some gardeners recommend planting plants near raspberries that would repel insects. These include garlic, lavender, basil and mint.
What harm does it do?
At the very beginning of infection, the mite does not pose a threat to the condition of the plant: the leaf on which the mites have settled dries out and falls. However, pests reproduce at high speed: one female produces up to 200 embryos in 30 days. The egg matures in just 3 days. In one growing season, only one parasite gives life to fifteen generations.
Adults and larvae feed on plant sap through punctures on the inside of the leaves. The multiplied population covers the entire above-ground part of the raspberry.
Mass infection causes enormous harm:
- shoots freeze and stop developing;
- the leaves first become marbled, then fall off;
- the buds do not open and the ovary does not form in them;
- the immunity and frost resistance of the plant decreases;
- Crop losses with severe infection amount to up to 70%.
It reproduces most quickly in hot, dry weather and especially in dense plantings.
For your information! Spider mites are carriers of a viral disease that is dangerous for raspberries - mosaic. The simultaneous impact of a pest and a disease can destroy all berry plantings in a short period of time.
Reasons for appearance
The most common cause of infection of raspberry bushes in the garden is themselves. Very often, unscrupulous sellers do not carry out the required treatment of plants, selling them already infected. If, when choosing a seedling, cobwebs or various spots (from white to dark shades) are noticeable on the leaves, it is best to refuse it and choose another one.
It is important to know that ticks very often hibernate in purchased soil. They may not appear for some time, as they say, until favorable conditions arise for them.
To avoid the appearance of the parasite, it is recommended to disinfect any purchased soil in advance.
The best method for this is calcination under the influence of hot temperature.
Tick eggs can be carried by birds, insects, and also people. You can easily bring mites home from an infested garden, where they will happily begin to settle on your house plants.
Spider mites are especially often active on raspberry bushes in hot and dry weather.
How to fight with drugs?
The fight against the pest begins at the first signs of its appearance on the bushes, preventing its mass spread. There are several ways to solve the problem.
Chemicals
To reliably destroy pests at all stages of their development, only chemicals are used.
The tick does not belong to the class of insects, so specialized means are needed to combat it:
- Antio is a highly toxic drug that destroys pests at all stages of development after a single spraying.
- Fufanon is a broad-spectrum insectoacaricide. It disrupts the digestive system of pests and causes their death within 24 hours. The protective effect of the drug lasts 2 weeks.
- Akrex is a drug that combines fungicidal and acaricidal properties. The plants are sprayed with a solution of 0.8% concentration 2 times with an interval of 10 days. The product is highly toxic to humans, so protective agents are used during processing.
- Actellik is a non-systemic drug with enteric contact action. Once in the pest's body, the product disrupts the functioning of enzymes that carry out neuromuscular impulse transmission. Accumulating in the tissues of the victim, the drug blocks the functioning of all organs of the pest. The effect of the product begins 2-3 minutes after spraying. The activity of the product lasts 14-15 days.
- Anti-mite – the drug destroys adults and larvae within 2 hours after application. The action lasts 14-15 days. 10 ml of the product is diluted in 10 liters of water and 3 liters are used for 10 medium-sized bushes.
- Dimethoate is a highly toxic product that can be used no later than 40 days before harvesting the first berries. The drug has a systemic effect, accumulates in plant tissues, retains its properties for 25 days.
Carefully! Chemicals must not be used to treat plants during the formation and ripening of berries.
Biological agents
The use of biological products is an excellent alternative for opponents of chemistry. The following agents are most effective in combating spider mites on raspberries:
- Akarin – contains a neurotoxin isolated from the bacteria Streptomyces avermitilis. Paralyzes the nervous system of adult parasites. The drug is applied to the underside of the leaf 3 times with an interval of 10 days. This frequency is necessary to destroy insects hatched from eggs laid by females.
- Bitoxibacillin is a domestic drug produced since the 80s of the last century. It is especially effective to use the product during the larval stages of pest development. The drug is harmless to humans and animals. The bushes are treated with a solution of 1 mg per 10 liters of water 3 times every 3 days. Spray the inside of the leaf, where the pest mainly breeds.
- Fitoverm is a drug that destroys the digestive system of the pest. Treatment is carried out in cloudy weather with a solution of 10 ml per 8 liters of water. The protective effect of the drug lasts 30 days.
Biological description of the pest
This is a microscopic insect. It is possible to see its outline on the plant with the naked eye. The female is slightly larger than the male, measuring slightly more than 0.5 mm. Life expectancy 1 month. During this time, the insect lays eggs, from which new individuals emerge. The life cycle of a tick is as follows:
- The egg looks like small drops located on a web, gray in color. It stays in this state for three days.
- Larval stage. Slightly larger than the size of an egg. The body has three pairs of legs, the period of maturation takes place in 24 hours.
- Nymph. Intermediate stage of growing up. There are 4 pairs of legs on the body.
- Sexually mature individual.
Important! In a month, the female is capable of laying more than 200 eggs.
Fighting cobwebs on raspberries using folk methods
Insect repellents prepared according to folk recipes are not capable of destroying pests. Their effect is mainly repellent, so the bushes are sprayed for preventive purposes.
The following means are used against the pest:
- Onion infusion. 20 g of onions are added to 1 liter of water and left for 7 hours. Then filter and spray the bushes.
- Dandelion infusion. 20 g of roots are infused in 1 liter of warm water for 2 hours.
- Garlic infusion. Take 150 g of garlic pulp per 1 liter of water and leave for 5 days in a dark place. Before use, 5 ml of infusion is diluted in 1 liter of water.
- Infusion of tobacco. Crushed young leaves in the amount of 45 g are poured into 1 liter of water and the bushes are sprayed every other day for a week.
- Mustard solution. 1 package of dry powder is dissolved in 5 liters. water, spray the bush.
- Horseradish decoction. 1 kg of roots is crushed, poured with a bucket of water and boiled. The resulting broth is infused for 2 days, filtered. The resulting product is sprayed on raspberries every 10 days. The decoction is stored in a cool place.
- Vinegar. 1 l. table vinegar is diluted in 5 liters. water and spray.
Wintering
When leaves begin to fall and daylight hours decrease to 16 hours, many fertilized females often burrow into the soil. There they enter diapause. In this state, they do not feed and practically do not move. Diapause allows you to avoid the negative effects of high or low humidity and too low a temperature.
Wintering species can easily tolerate temperatures down to -9 °C. Spider mites, not adapted to such conditions, die at temperatures below 0 °C. Winter varieties stand out among others. Such individuals can withstand temperatures down to -28 °C
It is important to consider that, unlike other species, overwintering spider mites continue to develop even under such conditions
Many wintering species try to move to greenhouses, conservatories, hotbeds and human dwellings. In spring, arachnids usually settle on the nearest weed plant. After a short period of time, the colony returns to its old place of residence or finds a new, more favorable one.
Terms and rules for spraying bushes
To achieve maximum effect, pest control on raspberries is carried out comprehensively, using several means simultaneously. As a preventive measure, even before the leaves bloom, the bushes are sprayed with a urea solution at a concentration of 6%. If preventive spraying does not produce results, chemical and biological products are used.
The first treatment is carried out before the female lays eggs. All damaged parts of the plant are removed from the bush and burned. The soil under the bushes is dug up to a shallow depth so as not to damage the roots. When spraying a bush with chemicals, the surface of the soil must also be treated.
After preparatory measures, a comprehensive fight against insects begins. Practice shows that three-time treatment of bushes according to the following scheme is most effective:
- a chemical to kill adults;
- re-treatment after 10 days with a chemical to destroy a new colony of pests hatched from eggs;
- after 10-14 days, preventive treatment with a biological product to protect the plantings from re-infection.
Folk remedies can be used at any time, since they are non-toxic and do not accumulate in fruits. After destroying the pests, until the end of the growing season, you can periodically spray the bushes with a product prepared according to one of the folk recipes. This will help avoid re-infection of raspberries with spider mites.
What to process
Remember that mites are not insects, but arachnids, so treating raspberries against mites is carried out not with insecticides, but with acaricides (or insectoacaricides). Suitable preparations are Fufanon, karbofos, metaphos, colloidal sulfur. Since spider mites affect so many garden crops, you won’t solve the problem by fighting the mite only on raspberries - you need to treat the entire garden. If there are a lot of mites, the plantings are treated several times - after fruiting and in the spring, before buds open. Trim old raspberry shoots in a timely manner.
Mistakes when caring for a beautiful indoor flower
Actions that lead to increased pest activity:
- the use of organic fertilizers, this contributes to the withering of flowers and leaves;
- too frequent watering: it is recommended to water balsam no more than 2 times a week in winter, and every other day in summer;
- infrequent watering is also harmful: when the soil dries out, the flower weakens;
- the temperature is low or, conversely, high, it is recommended to maintain this indicator at +18...+22°C;
- when the balsam develops, it needs to be fed once every 10 days; this should not be done too often, the flower may die as it cannot tolerate excess nutrients;
- dense installation of pots on the windowsill;
- Water is not removed from the pan, which contributes to waterlogging of the soil and root system;
- The leaves of the flower are not sprayed (this should be done daily).
