True rose lovers find it difficult to accept the fact that the beauty of their favorite plants can be destroyed.However, it is worth remembering that these shrubs are a tasty morsel for many pests, including insects that show no mercy to the queen of flowers.
The tissue of the leaves is eaten, the juices are sucked from them, the larvae dig tunnels in the shoots and various vegetative parts are deformed and the tissues overgrow in the form of galls. All these types of damage make us realize that roses require careful care. Properly selected chemical preparations are necessary to control pests. When the pest is easily covered with the agent while spraying the plant, contact is sufficient.
To fight pests hidden in rose tissues, it is necessary to use preparations that penetrate deep into the plant. Their action is called systemic, because they are moved along with the juice and reach even those parts of the plant that have not been sprayed with a chemical agent. This circular route will also reach the digestive tract of insects.
As with the control of common rose diseases, which include, for example, rust, powdery mildew, and black leaf spot, in the protection taken against pests, protective measures should be used in the appropriate times.In the case of insects, useful there is information about the biology of the development of species, that is, knowledge about when the different stages of development appear and what is the number of generations that may develop during the year.
Where does the white coating appear on rose buds?
The white coating on the buds and on all above-ground parts of the rose is a symptom of a fungal disease - rose powdery mildew (Sphaerotheca pannosa var. Rosae). Infected buds and shoots should be removed and spraying with anti-fungal plant protection products, the so-called fungicides.
- says Dr. Eng. Tomasz Mróz
Beautifully fragrant lush-flowered rose varieties
Pink rose
The very mysterious lesions on rose leaves include those left by the period of Megachile centuncularis. It is an insect similar to and related to the honeybee, but not colonized. The specimen makes precise semicircular cuts in the leaf blades of roses.Interestingly, it does not feed on these plant fragments, but transports them over long distances and uses them to cover the cradles of its larvae.
Aphids
There are several species of aphids on roses. The most common are bimodal aphids: Metopolophium dirhodum and Macrosiphum rosae. Young aphids hatch from the eggs in spring. Depending on the weather, this takes place in April or at the turn of April and May.They feed in large numbers on flower and apical budsThey look like green plants in color, but their presence is revealed by sticky excrement in the form of honeydew and white exudates. The harmfulness of these small insects is mainly the inhibition of the growth of shrubs, and sometimes also their deformation.
Rose Nimułka
A very common cause of rose leaf damage is the Hymenoptera Blennocampa phyllocolpa. Seeing the tubularly rolled leaves, we can immediately identify the culprit.The individual leaves take on a characteristic shape due to the secretions of the female insect, which lays eggs along the main nerve.
The leaf is tucked underneath on both sides, thus providing shelter to the larvae developing in the center of the "tube". The deformation of the leaf and the scraping of the leaf tissue by the larvae causes it to fall off the plant prematurely. Black, approximately 0.5 cm adults appear in April, and fertilized females lay eggs (causing the leaves to curl) from May.
Dangerous hymenoptera larvae
Damage to rose shoots is mainly caused by the larvae of two species of wasps: Ardis brunniventris and Cladardis elongatula. The invasiveness of these pests is high as the larvae dig tunnels inside the shoots. The ditch cutter does this from the top of the plant where the larva hatches.It grows by tunneling down the shoot, and the corridor length is up to 5 cm.When the larva is of sufficient size, it gnaws a hole through which it exits into the soil, where it pupates.
Leaves a damaged shoot tip which turns black and dies. The rose leaf larva follows the opposite direction of travel. It bites close to the base of the shoot and travels upward. Its tunnels are twice as long as those bored by the furrow chaser.The activity of both pests paves the way for the attack of fungal and bacterial pathogens.The wallworm destroys the plant habit, and flaccidity reduces the mechanical strength of the shoots.
Rose Jumper
The Edwardsiana rosae are small (about 3 mm long) Heteroptera bugs. Feeding on rose leaves, they leave very characteristic traces.
These are white discolorations on the upper side of the leaf blade.These discolorations increase during the season and with high intensity of the pest individual spots merge into larger ones, which makes the entire leaves white.The leafhoppers responsible for this damage should be found on the underside of the leaf blades.In addition to adults, there are also larvae and nymphs that feed in a similar way - sucking the juice from the plant tissues.
Rose chimpanzee
Mainly wild rose Rosa canina is susceptible to attack by the rose bush Diplolepis rosae.The larvae develop on rose shoots in special growths called galls.The overgrown plant tissues create a multi-chamber dwelling for the larvae.
The jagged galls are initially green-red, turning brown-black in autumn. Inside, the larvae winter, which transform into pupae in the spring. Soon after, adult insects emerge from their galls.
