Content
Roses are one of the most popular garden decorations. Gardeners cultivate them, despite the capriciousness of many varieties in care and susceptibility to pest attacks. One typical problem is rose sawfly on roses. To combat it, there is a fairly wide arsenal of remedies - both folk and store-bought drugs. But you need to know how to use them correctly so as not to harm the plants.
What does the rose sawfly look like?
The roseate sawfly is a fairly large hymenopteran insect 7-10 mm long. There are several varieties of it; gardeners most often encounter the top-down type. The natural habitat of the pest is Europe, Eastern Siberia, North Africa. It has also successfully taken root in North America and Central Asia.
Females can be distinguished from males by their thicker abdomen and the presence of a pointed “tip” - the ovipositor. The chitinous shell of the insect is glossy, orange-black, the wings are thin, almost transparent, shimmering with golden yellow.Two antennae are clearly visible on the head, to which the pest owes its popular nickname “fatwhisker”. From the photo you can see that the descending roseate sawfly slightly resembles a miniature wasp.
Thanks to its bright color, it is easy to spot the roseate sawfly on a bush.
Females are not fertile, laying about 70 eggs per season. They are very small (less than 1 mm), yellowish, as if made of glass. The insect “hides” them under the bark of non-lignified stems (the growth of the current season) - the shoots are deformed, and a “cavity” remains after laying.
After ten days, the eggs hatch into larvae - translucent whitish pseudo-caterpillars about 4 mm long. As they “grow up” through molting, the color changes to brownish, black spots appear along the body and near the head, and limbs are formed.
The larvae crawl in groups throughout the bush, gnawing the stems from the inside and gradually descending to the base of the shoots. There they pupate and overwinter in the ground, in a light beige cocoon made of “spider web”.
Roseate sawfly larvae, distinguished by their gluttony, are predominantly nocturnal.
In the spring, when the temperature reaches about 10 °C, adult individuals emerge from the cocoons in batches. They do not live long and do not cause direct harm to the bushes, but they manage to lay another batch of eggs in 2-3 stages.
What harm does
Infestation of bushes by insects means, at a minimum, late and poor flowering.In most cases, you can’t expect it at all this season - roses are massively losing buds and flower buds on the affected stems.
A rose with darkening and withering shoots noticeably loses its decorative value
Mechanical damage left by the pest on the shoots is a “gateway” for pathogenic fungi. The experience of gardeners shows that infection with pathogenic microflora is almost inevitable.
Bushes attacked by the rose sawfly are greatly weakened. Their cold resistance and overall endurance drops noticeably. It is not a fact that the plant will survive the coming winter. The more demanding a variety is to care for, the higher the likelihood of its death.
Signs of defeat
The most obvious evidence of a pest attack on bushes is the presence of adult individuals on them. It is difficult to notice the larvae of the descending roseate sawfly - they hide in the stems and rarely come out.
The damage left on the stems from egg laying lasts a long time and does not completely “heal”
What symptoms appear on the bushes after insect damage and indicate the presence of roseate sawfly larvae:
- the sudden onset of the plant's withering process when properly cared for;
- unnatural curvatures and thickenings on the stems;
- black cavities inside the shoots if you break or cut them;
- thin, translucent “cobwebs” at the bottom of the bush.
To make sure there are rose sawfly larvae on the bush, you will have to cut several stems
If rose sawfly larvae also feed on leaves, holes appear on them. At first they are very small, more like punctures, but gradually increase in size, only veins remain from the leaf plates.Less commonly, the insect eats leaves from the inside, leaving “passages” similar to tunnels, feeds on stamens and pistils, and damages rose petals.
Leaves and stems affected by rose sawfly gradually dry out and die.
Reasons for appearance
The roseate sawfly is a flying insect. It moves freely over fairly long distances in search of food. Wild rose hips can “attract” it to your garden plot, so it is recommended to get rid of its thickets.
The gardener himself can “infect” rose bushes. The most common methods are the use of soil in which the larvae overwinter when replanting, throwing out shoots affected by the roseate sawfly into a compost pit, and “storing” plant debris in an area.
How to deal with rose sawfly on roses
To get rid of sawfly on roses, you can use both folk remedies and insecticides. The method is chosen taking into account the degree of neglect of the problem. The greater the number of pests on the bushes and affected shoots, the higher the likelihood that folk remedies and biological products will not help, and you will have to use “heavy artillery” in the form of chemicals.
Preparations for rose sawfly
When using chemicals against roseate sawfly, you must follow the instructions exactly and use personal protective equipment. Exceeding the dosage of insecticide in solution or more frequent treatments can harm human health, other plantings, and beneficial fauna.
Aktara
A universal systemic insecticide based on thiamethoxam, for many insects, including the roseate sawfly, which is a neurotoxin. Belongs to hazard class III.After treatment, it “impregnates” the plant tissue within 2-3 hours, the effect lasts for two months, regardless of weather conditions.
When using Aktara against roseate sawfly, you need to take into account that this insecticide is toxic to bees
When using Aktara against roseate sawfly, you need to take into account that this insecticide is toxic to bees
Tanrek
Insecticide based on imidacloprid. Roseate sawfly larvae die when feeding on the tissues of treated plants, while adults die when they come into direct contact with the drug solution. The product begins to act on the 3rd day after spraying, the effect lasts for 20 days. Tanrek cannot be combined with other agrochemicals; soap shavings must be added to the solution.
Tanrek can be used to protect roses from rose sawfly not only in the garden, but also at home
Angio
An insecticide, due to the presence of two active substances (cyhalothrin and thiamethoxam), penetrates into the body of the roseate sawfly through the outer chitinous integument and during feeding. Pests die within half an hour after contact due to internal “burns”. One treatment is enough for 20-40 days (depending on the frequency and intensity of precipitation).
Enzhio insecticide cannot be used in water protection zones; plants are deadly to bees within two days after treatment
Fitoverm
A very popular insectoacaricide of biological origin with enteric contact action. The active substance is aversectin-S. When a roseate sawfly enters the body, it deprives it of the ability to feed; after 2-3 days the larvae die. The protective effect lasts up to 20 days.
Fitoverm is not phytotoxic, it can also be used on fruit-bearing garden crops
Bitoxibacillin
A biological product based on a combination of “natural” toxins and bacterial strains. “Saturating” plant tissues, it enters the digestive tract of roseate sawfly larvae and provokes the spread of alkali from the intestines throughout the body, as a result of which the pests die. The product provides protection for approximately 20 days and is toxic to beneficial soil microflora.
Bitoxibacillin against roseate sawfly acts rather slowly and is incompatible with other agrochemicals
Folk remedies for sawfly on roses
Folk remedies are used mainly to prevent rose sawfly attacks on rose bushes. If the pest was not noticed in time and multiplied in numbers, they will not help get rid of it; the gardener will only waste time, aggravating the problem.
How can you treat roses from sawfly:
- Wood ash. Helps get rid of roseate sawfly and any sucking and gnawing pests. It is enough to sprinkle the soil around the tree trunk with ash (about 0.5 liters per plant), and then water the bushes well. The components penetrate into the tissues and juice, making them bitter and “unpalatable” to the roseate sawfly. The effect lasts for 5-7 days. Mustard powder and tobacco dust act similarly.
- Sagebrush. The pungent smell of its infusion helps to repel adult rose sawflies from roses. Fresh leaves and stems are crushed, poured with hot water in a volume of approximately 1:3 and left in a dark, warm place for 3-4 days, periodically vigorously shaking the liquid. The finished infusion is filtered and used for spraying bushes and soil in the tree trunk circle.
- Nightshade. Poison for most caterpillars, including the roseate sawfly. The product is prepared by boiling 1 kg of fresh leaves in 2 liters of water (four hours).The resulting liquid is filtered, water is added (0.8-1 l).
Wood ash not only ensures that roses are “inedible” for the rose sawfly, but also enriches the substrate with potassium, phosphorus, and magnesium
Agrotechnical methods
Proper agricultural technology is the best remedy for the roseate sawfly, allowing you to prevent its attacks on bushes. Proper watering and fertilizing play a very important role in maintaining the endurance and ensuring good immunity of roses. In addition, proper pruning is important. Moist, stale air accumulates in the middle of a thickened bush.
Sanitary pruning for the purpose of thinning the bush is carried out in spring and autumn
Prevention
It is much easier to prevent the appearance of roseate sawfly than to fight it later. Effective preventive measures:
- Construction or purchase of traps for adult individuals or scaring away the roseate sawfly with any strong-smelling infusions, planting flowers and herbs with a characteristic aroma next to the flowerbed.
- Annual spraying of roses and tree trunks with solutions of universal insecticides in early spring and late autumn.
- Mandatory renewal of the mulch layer and deep loosening of the soil at the roots in preparation for winter.
- Collection and destruction of all plant debris after flowering and autumn pruning.
Loosening the tree trunk in the fall destroys the shelters in which the roseate sawfly larvae gather to overwinter.
Conclusion
The rose sawfly on roses is an insect that can cause serious harm to plants, which is why their decorative properties suffer greatly. To combat the pest, you can use both folk remedies and insecticides, but it is easier to prevent its attack on the bushes. The best prevention of rose sawfly attacks on roses is competent agricultural technology; there are other simple measures.
