Falling Leaves At The Rose. Pests. Continuation

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Weakened rose bushes after wintering become easy prey for pests. Sucking the juice from the leaves, they provoke early leaf fall. At the first sign, gardeners begin to treat plants with chemicals, destroying at the same time beneficial insects. What preventive control measures can be applied to roses?

Rosaceous scale insect

A sucking insect has a body up to 3 mm long, yellowish or brownish, covered with a whitish waxy shell.

Sexually mature individuals are very different from each other. Females lack legs, wings, shell is rounded, convex. Males have a smaller size, legs, wings for active movement, poorly developed mouth organs, a slightly elongated flat shield.

After mating in May, males die. Females attach to branches or leaves, lay eggs under themselves. Within 10 days, they incubate until the larvae hatch. For an active lifestyle the young animals were named "tramps".

For several days they are looking for a suitable place for themselves to eat. Then they attach to the plant motionlessly. They molt several times, overgrowing with a powerful shell, turning into adults.

In places where scale insects accumulate, white plaques resembling dandruff are formed. On the outside of the leaf blade, yellowish or reddish small spots appear. With a strong defeat, plant growth slows down, the leaves are deformed, covered with sweet secretions (paddy), are populated with a sooty fungus, gradually turn yellow, fall off.

Control measures:

1. Keeping newly acquired seedlings in quarantine for several weeks. Preventive spraying with appropriate preparations of the plant itself, the transport soil.

2. Top dressing with phosphorus-potassium fertilizers. Limited nitrogen application. Mulching the soil adjacent to the bushes with a layer of 3-4 cm.

3. Timely pruning, burning of old, diseased branches.

4. With a small number of pests at an early stage, infusions of garlic, celandine, hot pepper, walnut, tobacco are used with an interval of 5-7 days.

5. The use of intestinal insecticides on plants, near-stem circles: Aktara, Bankol, Actellik (diluted according to the instructions).

Slobbering penny

Insect with an elongated yellowish body up to 6 mm with a varied brownish pattern. The upper part is covered with small sparse villi. The head is triangular. Rigid dense elytra are located along the abdomen.

Hibernates in the egg phase. At the end of spring, larvae hatch from them, spreading along the stem. In the middle of summer, they turn into adult pests with an active lifestyle.

In September, the female lays in groups of 30 eggs in the cracks of the stem at a level of 5 cm from the ground. With the first frost, insects die. The pest spends all phases of development under foamy secretions, creating favorable conditions for its habitat. Produces only one generation per year.

Individuals hide under the leaf, at the point of growth, shoots, pedicels. They feed on the sap of roses, deforming the stems, causing wrinkling of the leaves, and early abscission.

Control measures:

1. Prevention of the appearance of the pest are:

• destruction of weeds;

• moderate watering (avoid waterlogging of the soil around the plants);

• timely cleaning of organic residues;

• planting spicy-aromatic herbs with a pungent smell (lavender, lemon balm, thyme) near rose bushes.

2. With a small settlement with a pest, it is removed together with the foam by hand.

3. Use infusions of garlic, tansy with the addition of soap.

4. In case of mass infection, the bushes are treated with water, washing off the protective layer from the penny, then the chemicals karbofos, spark, intavir are used.

Walnut

Hymenoptera insect up to 4 mm long with a dark body, reddish belly. Hibernates in the larval phase inside the gall - a reddish hairy growth with a diameter of 0.5-5 cm.

In the middle of spring, an adult emerges from the pupa. Male representatives are born earlier. Crawling over the plants, they wait for the females.

In early summer, the uterus lays eggs on leaves or stems during the flowering phase of roses. The hatching larvae form a protective layer in the form of a gall, where they comfortably feed all summer. One generation comes out per season.

The affected leaves dry out over time, fall off prematurely.

Control measures:

1. Timely harvesting, destruction of the affected parts of the plant along with the pest, while the larvae are inside the growth.

2. Chemical methods of control do not bring the desired result.

Knowing completely all the reasons for the dropping of leaves on roses, you can easily navigate on the spot. Apply the right methods to address the root cause. Save your pets from certain death by prolonging their life for many years.