Rhododendrons are exposed to a large number of pests and diseases. To prevent the death of plants, it is worthwhile to constantly check the condition of the shrubs, if necessary, to take actions to eliminate harmful organisms and diseases. Consider the main pests of rhododendrons in the photo and talk about combating each of them.
Striated weevil
This is one of the most formidable pests. Many plants suffer from it, including rhododendrons. Its danger lies in the fact that mature insects eat foliage, flowering, buds, and embryos, while in the ground, destroy the root system down to the trunk. The bark of young plants gnaws completely, which leads to wilting and drying.
The foliage goes along the curve, starting from the ends. Damaged plants lose their beauty.
Mature individual reaches 0.8-1 cm, colored with a blackish pattern with yellow splashes on massive, corrugated wings with a small nose. Mature insects move a little and do not fly. They devour the plants only at night, and in the daytime they hide in the ground, therefore their detection is a very difficult task. If the plants bloom, then they can be found in the buds themselves. When detected in the morning, insects from touch touch and fall down, making them invisible against the background of the soil.
Did you know? Rhododendron can grow to the height of a high-rise building.
The larvae are fat, have a light yellow color, reach a length of 1.5 cm and are a few millimeters thick, with no limbs. Externally similar to the embryos of May beetles. They devour the rhizomes and the beginning of the trunks because of what the rhododendrons die. Under suitable conditions, this trash gives offspring throughout the entire calendar year, but especially in the second half. For plants, this is the black period, since pests show maximum activity. Insects ripen by the end of winter in the form of pupae, and by the end of spring adult beetles are ready to devour greens. Eggs laid by females, best ripen in fertilized soils or compost heap.
For applying a large deformity of foliage, flowering and plant trunks enough for a few individuals, and the larvae can devour a lot of green seedlings.
To deal with this insect is a big job, in view of the difficult determination of their presence in the soil. Large larvae and mature beetles have low sensitivity to treatment with drugs. In identifying the larvae of this insect in containers in which the green seedlings of rhododendrons grow, it is necessary to transplant the plants into the new soil, and with the old it needs to be thermally treated.
Important! When transplanting should prevent the transfer of larvae, which are located near the root system of the seedling.
For prophylactic purposes, all seedlings should preferably be treated with a mixture of insecticide solutions.
In the period of high activity of beetles, plants must be treated with insecticidal and acaricidal solutions, preferably at night, when insects come to the surface.
Spider mite
Spider mite settles in plants in dry and hot weather, feeding on foliage liquid. In view of the tiny size, it is almost imperceptible to the naked eye. And only a superficial analysis of the plant will determine the presence of this pest. One gets the impression that the bottom of the foliage is entwined with a fine web, and the leaves themselves are colored in brown tones, wither and die.
Discover the types of spider mites.
Important! The important point is that the maturation of the tick is 8-10 days, and in the warm season more than 20 new generations appear on the plants. Therefore, to combat it, it is necessary to make weekly treatments with systemic pesticides solutions: "Diazinon" and "Agravertina".
Shatter-pan
This is a small roundish insect with a brown color. Larvae make holes in the bark with their proboscis and attach themselves to the trunks of plants. Because of this, the rhododendron loses its vitality, looks pleasant and dries out over time. To clean the leaves of this pest, you can use a brush, cloth, alcohol or soap solution.
To prepare an alcohol solution with soap, you need to take 10-20 g of liquid soap, the same amount of alcohol and pour one liter of water. First check how sensitive your plants are to this solution on a single leaflet. At high sensitivity, try to apply the solution directly to insects. If the lesion is very severe, then it is recommended to use such drugs: "Actellic", "Phosbecid" and "Aktara" in accordance with the instructions.
If you want your rhododendrons to be healthy, find out how to deal with a false shield.
Tobacco thrips
It is a pest of small size with a noticeable black color. Eats foliage and flowering from rhododendrons. Because of this, leaves and buds wither, fade and die before time. The development of green plants is slowed down, the buds are deformed. To combat tobacco thrips, nicotine solutions, spraying with a dust of a metaphos or Phosphamide emulsion at the rate of 2 g per liter of water are used.
Rhododendron bug
Rhododendron bug is recognized as the most harmful and popular insect that devours these plants. To notice its presence will help the little dark dots on the underside of the leaves - an area where the pest makes holes and feces.
The destruction of the bug is carried out with the help of contact and systemic preparations. But the treatment must be done carefully so that the pest does not develop immunity to insecticides.
Did you know? The life span of rhododendrons can reach 100 years.
Greenhouse whitefly
Hothouse whitefly is a carrier of various infectious diseases. It breeds all year round. It is very easy to notice its presence on plants - it is a small white midge at the bottom of a leaf.
To overcome this pest, it is recommended to use pesticides safe for insect pollinators, and recently, neonicotinoid preparations, in which acetamiprid, imidacloprid, clothianidine, thiacloprid and thiamethoxam are active substances.
Rhododendron whitefly
This pest can be found mainly on rhododendrons with large leaves. The greatest effect in the fight against these insects is the treatment of foliage from the bottom with a nicotine solution and an oil emulsion in the spring and autumn. For prophylaxis, it is advised to treat with the help of nicotine dust in the summertime, and to tear and destroy damaged foliage.
Did you know? Honey from certain types of rhododendrons has hallucinogenic and laxative properties, which was known in Rome and ancient Greece.
Shellfish
Rhododendrons are badly damaged by mollusks and snails, devouring the leaves and flowering of these plants. Fighting them consists of two methods: either collect by hand or process it with special means - molluscicides.
Passed Slug
This pest damages the foliage of green rhododendrons, making large holes in it.
Important! Passed slug can destroy plants in a very short period.
The slug must either be destroyed by hand, or water the plants with TMTD solution.
To combat each pest, it is important to timely detect and use the most effective measures that will help preserve all the beauty and sophistication of rhododendron plantings.
Check out the most popular winter hardy rhododendron varieties.