Plum pests and measures to combat them

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Published: June 26, 2019

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As they say, you need to know the enemy by sight, then the gardener will not be in danger of losing his crop. The most harmful insects for plums are those that feed on fruits, as well as those that prefer young shoots. By the way, under the influence of the last ovaries on plum trees there may be no ovaries at all. Here are the plum pests you should know about.

1 Plum sawfly
2 Codling moth
3 Aphids
4 Pliers
5 Wrinkled sapwood
6 Centipede
7 Prevention of the appearance of harmful insects on plums
8 Why are plums bleached? 8.1 Autumn whitewashing
8.2 Spring whitewashing

9 Some means of protecting plums from harmful insects

Aphids

Several types of aphids parasitize plums: hop aphid, pollinated plum aphid, peach aphid, cane aphid, potato aphid and thistle aphid. Each of these species can have several generations. Most often, aphids live on leaves or petioles, sometimes on young shoots and buds. It contaminates them with honeydew secreted in large quantities - a black sticky coating. Colonies of insects inhabit the underside of the leaf blade, the edges of which are curved downwards. When aphids multiply massively, the tops of the shoots begin to lag in growth and dry out.

Aphids deprive plants of a significant amount of nutrients, the deficiency of which can cause a decrease in yield and winter hardiness of trees, a decrease in the weight and commercial value of fruits, and a decrease in their sugar content. Aphids are also dangerous because they are carriers of viral diseases, including the most harmful - sharki.

Plum shoots and leaves infested with aphids

Control measures. Collection and destruction of damaged plant parts. The first chemical treatment against aphids is carried out on the green cone, the next - after flowering, and then, if necessary, every 14 days 1 - 1.5 months before the crop ripens. Recommended chemicals: Calypso 480 KS - 0.15 l/ha; Mospilan 20 SP, 0.125 kg/ha; Novaktion 440 VE, 1.2 l/ha, as well as BI-58, Pirimoru 500 WG, Kinmiks, pyrethroids (Cypermethrin). The broad-spectrum insecticide Intavir destroys not only aphids, but also their carriers - ants.

Entomophages play a significant role in regulating the number of aphids: anthocoris bugs, coccinellids, lacewing and predatory fly larvae, earwigs and ladybugs. The presence of a large number of insect predators for aphids can significantly reduce the number of treatments of crops with pesticides, so it is advisable to use drugs that are selective for beneficial fauna.

How to fight parasites?

How to treat plums after flowering against pests? Experts recommend first finding out the type of parasite and determining its location in the winter.

For example, to combat sawflies, the following sequence of actions is followed:

Timely treatment of plums after flowering against pests allows you to preserve the vital indicators of the fruit crop. It is recommended to collect dead insects in a separate container and destroy them outside the garden plot.

What to do if the leaves curl on a plum tree, how to treat it? This sign indicates the presence of plum aphids. Insects feed on plant sap, the lack of which leads to the destruction of leaves and the fall of young fruits.

You can get rid of parasitic insects using a solution of kemifos. It is used before young buds bloom and before fruit crops bloom. In addition, when carrying out such treatment of plums after flowering, it is possible to reduce the population of parasitic organisms.

Source

Shields

Acacia false scale

In plum orchards, damage is mainly caused by the comma-shaped and Californian scale insects, plum and acacia false scale insects. Scale insects are small, sedentary or immobile sucking insects. The top of their body is covered with a shield of shed molt skins. Females lack legs and often eyes; they lay up to 1000 eggs.

Larvae and females are harmful; they pierce leaf tissue or wood while feeding with their proboscis. The pest's saliva contains substances that have a detrimental effect on plant cells. During mass reproduction, insects are able to completely cover the branches and trunks of fruit trees. A large accumulation of female larvae causes drying of internodes, death of shoots and reduced yield. The damaged bark gradually dies, the leaves turn yellow and fall off, and the fruits are not colored. The sucking of juices by scale insects leads to weakening of plants. Trees lose frost resistance and are more easily affected by bark beetles and black cancer.

Acacia false scale (Lecanium corni Bouche) is distinguished by the fact that it does not have a dense protective shield and is quickly susceptible to insecticides. Its scutellum is thin, fragile, hemispherical, brown or brown - the color of the plant bark.

California scale insect (Diaspidiotus perniciosus Comst.) is most harmful in the southern gardening zone. Its larvae initially have a white shield, then it becomes gray, then black. Overwinters on the bark as first instar larvae. In the spring, the larvae grow, transform into second instar larvae, and then into females and males. Subsequently, the females give birth to actively moving larvae - “vagrants”, spreading through the tree and by the wind to other trees. The entire development takes about two months. In affected plants, growth is greatly weakened, the bark cracks, leaves fall off, individual branches dry out, and fruits become covered with red spots.

Plum false scale

Plum (or blackthorn) false scale insect (Sphaerolecanium prunastri Fonsc.) mainly affects apple and plum trees. The larvae of the second stage of development overwinter in the folds of the bark. In March, they are clearly visible on thin branches, where they begin to feed, sucking out the juice. In April, the larvae differentiate into a female and a flying male. The female's proboscis is tightly attached to the substrate. In May, after mating, females begin to lay oval white eggs under their own body continuously for three months, from which larvae immediately hatch. The larvae are able to move short distances.

The scale insect (Lepidosaphes ulmi L.) is so tenacious and harmful that when it appears, quarantine measures must be taken. When heavily infested, fruit trees die within a few years. The scutellum of the male is 1.5 - 2.0 mm long, the scutellum of the female is 3.0 - 3.5 mm long, and has the appearance of a brown comma. Eggs and larvae are milky white. The eggs overwinter under the shield of a dead female on the trunks and branches of trees. The larvae begin to hatch in May. They crawl along the trunk in search of food. Within two to three days, their body is covered with a shield. After two moults, they turn into young females, which by the end of summer lay eggs under the shield.

Control measures. Trees should be sprayed in early spring on dormant buds with ovicides, the destructive effect of which occurs when the drug penetrates the body of an adult and the egg. Effective drugs: Promanal 60 EC, 2%; Admiral, Aktara, Bankol, Aktellik, Apploud, Biotlin and Confidor Extra. Among the biological means of protection, Bitoxibacillin, Fitoverm and Intavir are used. To combat plum scale insects, winter spraying of trees with mineral-oil emulsions is recommended.

Signs of appearance

It is possible to determine the infestation of a plum tree by aphids before the ovaries appear during preventive pruning in the spring. Found in damaged areas under the bark, on branches in small cracks.

At the end of May and beginning of June, signs that a colony has started will be:

deformation, curling of foliage, drying out;
the appearance of growths on shoots;
yellowness on the leaves (along the veins);
bulge, unevenness on the plate.

The hallmark of the presence of aphids will be ants. They actively move along the branches and tree trunk, making the paths visible to the naked eye.

The reason for the appearance of ants: traces left by a green insect with a sugary taste, which the “ground dwellers” really like.

With the help of ants, aphids move to neighboring crops, as the former drag them from place to place.

When severely damaged by harmful insects, the back side of the plum leaf is covered with clutches of eggs and adult individuals.

Ticks

Brown fruit mite

Many types of mites damage plums: brown and red fruit mites, hawthorn mites, spider mites, plum leaf mites, etc. They are dangerous both during the period of active shoot growth and during crop formation. During the season, ticks produce 4 - 8 generations. Each female is capable of laying up to 100 eggs. Having settled on the leaves, mites suck the juices out of them, which disrupts the water balance of the plants, reduces the amount of chlorophyll, and stops the process of photosynthesis. Trees heavily infested with the pest produce small fruits.

The mass reproduction of fruit mites in many cases is associated with the inept selection of organophosphorus and other drugs that cause the death of the predatory enemies of the mites. In some cases, an increase in the number of ticks is associated with an increase in their fertility under the influence of the stimulating effect of certain pesticides on the body and the emergence of drug-resistant populations.

Red fruit mite

Control measures. The use of predatory mites from the family. Phytoseiidae. Cleaning tree trunks from old dead bark and whitewashing them in the fall with lime mortar. Ticks emerging from wintering areas are destroyed by treatment during the period of bud break or bud formation with Vertimek 18 EC, 0.75/1.0 l/ha and Fitoverm M, 2 EC, 0.6-1.5 l/ha. Spraying must be repeated 2 - 3 times.

The green bud stage is the optimal period for using the oil preparations Catane 800 SC and Promanal 60 EC. Spraying requires a large flow rate of working fluid - depending on the size of the trees, from 800 to 1500 l/ha. The garden is cultivated in dry, warm weather.

Wrinkled sapwood

A characteristic feature of this stone fruit pest is its small body length, up to 3 mm. The black beetle goes to winter under the bark of a plum tree. The spring season and until the beginning of August is the time for pupation of wrinkled sapwood larvae. The beetles emerge in May. They cause damage to trees by gnawing holes in the trunk and shoots: often near buds or at branch points.

Wrinkled sapwood

The beetles prefer sick, frost-damaged trees, and therefore occasionally live on healthy fruit crops.

Control methods and prevention

Timely removal and burning of damaged branches will protect against dangerous bugs before departure. Trees need whitewashing.

Leaf rollers

Plum budworm

Plum and rose leafrollers are small moths (their wingspan is 14 - 22 mm), appear in June and July. A clutch of 10 - 150 eggs looks like a flat shield with a diameter of up to 10 mm. The eggs overwinter on the bark of trunks and branches.

The caterpillars emerge in late April - early May and penetrate the buds, skeletonizing young leaves. The stamens, pistils and petals are gnawed out of the buds. Older caterpillars roll leaves into tubes or balls, damage ovaries and fruits, gnawing irregularly shaped holes in the pulp. Having completed feeding, which lasts 30–40 days, the caterpillars most often pupate in rolled up leaves. Massive damage by leaf rollers causes a slowdown in plant growth and leads to large crop losses. One generation of the pest develops per season.

Control measures. Pesticide treatment must be carried out before and after flowering with Fitoverm M, 2 EC, 0.90 - 2.25 l/ha. The use of parasites called ovi- eaters plays a very important role in reducing the number of pests.

False shield

This is a rather interesting insect. It leads a motionless lifestyle and completely merges with the tree. It sucks all the juices out of the plant and looks like the bud of the tree itself. This insect is quite easy to spot.

Treating plums against pests will not be difficult. But you will have to damage the tree, namely, cut down or cut off the branches and then burn them.

To prevent threats to the tree, also practice prevention. Spray Fufanon, Kinmiks and other chemicals.

Sawflies

The plum black sawfly (Hoplocampa minuta L.) is considered one of the most dangerous pests of plum trees. Yellowish or greenish-white larvae (false caterpillars) overwinter in silky cocoons in the soil at a depth of 5 - 10 cm and deeper. Adult insects appear a few days before flowering and at the beginning of plum flowering, feeding on pollen and nectar of flowers. When the air temperature reaches 15°C, the female lays 20 - 30 eggs, placing them one at a time in a cut made by the ovipositor in the calyx of a bud or flower.

Adult plum black sawfly insect

The larvae of the first instar feed on the pulp of the ovary, while the second and third instars eat away the central part of the fruit and damage the still soft stone, filling the ovaries with wet excrement with a characteristic bug odor. The larva damages 4 - 6 fruits, which then fall off. When heavily infested, black sawfly can destroy an entire crop.

The yellow plum sawfly (Hoplocampa flava) is also a threat to plum trees. Damage to fruit trees is caused by sawfly larvae, which grow to 5–6 mm. In mid-June the larva pupates. The emergence of sawflies begins a week before the plum blossoms. An adult insect, which has an elongated yellow-brown body and two pairs of transparent wings, lives about 7 days. The fertilized female lays up to 60 light green eggs in the calyx of the flower. One larva can destroy up to 5 plum ovaries, which stop developing and crumble. Crop losses reach 40 - 60%, and in some years - 80 - 90%.

Yellow plum sawfly insect and larva

Control measures. Digging and loosening the soil under the tree crowns. During the growing season (at the time of pinking and loosening of the buds, as well as immediately after the plum blossoms), the following preparations are used for spraying: Calypso 480 KS, 0.15 l/ha; Mospilan 20 SP, 0.125 kg/ha; Novaktion 440 VE, 1.2 l/ha. Karbofos, Rogor, Gardona, Cyanox, Tsidial and biological products - Lepitotsid, Entobacterin - are also used.

Centipede

These insects have a small black body about 5 mm long with transparent wings on which black veins are clearly visible.

The pest appears on plum trees after they finish blooming. Adult females lay eggs in the soft bones of the ovaries. Each female can lay up to 40 eggs at a time, so the colony of thickpods quickly expands and can greatly harm the plum.

The larvae quickly emerge from the testicles and feed on soft bones. As a result, the fruits stop developing and fall off. And the pest larvae “settle” in them for the winter. Therefore, all carrion should be immediately removed from the tree trunk circle and burned.

To prevent the spread of the pest throughout the garden, it is necessary to promptly remove all damaged fruits and ovaries on plum branches and in the circles around the trunk. The collected carrion can be collected in a dug hole, sprinkled with lime, or burned.

In the spring, before the start of sap flow, and in the canopy, in the process of preparing trees for winter, the trunk circles are dug up onto the bayonet of a shovel.

Before the adults begin to mate, special enzyme traps should be hung in the garden to catch the males.

It is necessary that the soil under the plum tree should always be moist, so in dry weather the amount of watering should be increased, and before the onset of winter, moisture-recharging watering should be carried out.

When planting seedlings, you need to maintain a standard distance between them so that the trees do not shade each other from the sun, and their crowns are ventilated with a draft. Immediately after the end of flowering, the plum is treated with insecticidal preparations to destroy the emerging fatty stems. To do this, you can use the following insecticides:

Chlorophos;
Insegar;
Fufanon;
Rogor;
Karbofos.

Also, after flowering, you can use a tank mixture of Kinmiks and Oksikhom to treat trees. This medication will prevent females from laying eggs. After 1.5 weeks, spraying is repeated with a mixture of urea, Horus and Confidor.

All of the pests described above can cause irreparable damage to plum trees, weaken their immunity, reduce productivity or lead to the death of trees. Therefore, you should regularly inspect the plum and at the first symptoms of pests, you need to start fighting them.

Plum moth (Grapholita funebrana)

The codling moth is widespread, most harmful in the steppe zone. The butterfly has a wingspan of 12 - 15 mm, the front wings are grayish-brown with a purple tint. The larva (caterpillar) is 12–15 mm long, pinkish-red in color, with a dark brown head. Adult caterpillars overwinter in dense cobweb cocoons in cracks in the bark, under loose bark on trunks, skeletal branches and in the surface layer of soil. Pupation of caterpillars begins 10–15 days after the average daily temperature passes 10°C. Codling moth butterflies appear shortly after plum blossoms. The female's fertility is 40 - 50 eggs.

The caterpillars emerge from the egg by gnawing a hole in the shell on the outside of the fruit. Once in the fruit, they eat away the passages in it, from which the gum flows out. Damaged fruits fall off and the yield is significantly reduced. The codling moth develops in one generation.

Butterfly and plum moth caterpillar

Control measures. Cleaning dead bark on trunks and main branches. Autumn plowing between rows, digging around tree trunks, applying trapping belts and systematically collecting carrion. Spraying with insecticides: Karate Zeon 50 KS, 0.3 l/ha; Calypso 480 KS, 0.2 l/ha; Dimilin 480 KS, 0.4 l/ha; Insegar 250 VDG, 0.4 l/ha. Repeated spraying of plum trees is carried out after 12 - 14 days. When the pest develops in the second generation (especially in the southern regions), a 3rd treatment of plum trees is necessary during the summer of butterflies. The new drug Lufox is especially effective at high temperatures and can be used up to three times per season at a dosage of 0.8 - 1.2 l/ha.

Western May beetle (Melolontha melolontha)

A large beetle 23 - 32 mm long with a stocky, wide and strongly convex abdomen. The larva is thick, arched, with six thoracic legs, reaching a length of 45 - 65 mm (Fig. 8).

Adults overwinter in the soil at a depth of 25 to 150 cm. At the end of April - beginning of May, the beetles emerge from their wintering grounds. They are active at night. During the day, adults eat leaves. The eggs are laid in the soil and the hatched larvae feed on plant roots. Having finished feeding, the larvae pupate in June-July and remain for the winter until next spring. Full development of the pest takes 3–4 years. Severe damage by beetleworm leads to withering and death of plant parts, reduced yield and deterioration in fruit quality.

Western May Khrushchev

Control measures. Autumn plowing and soil cultivation have an adverse effect on the development of the pest. Before planting a garden, you can use the drug Chlorpyrifos. It limits the number of larvae in the soil.

Spider web on a tree

Common spider mite

A small spider mite, rarely growing more than 6 mm, settles on the lower part of the leaves and forms a thin web. There he lives, feeding on leaf blades. During the years of mass reproduction, the web completely covers the crown of the trees, and mites destroy all the green mass and ovary of the plums.

To exterminate ticks, the drugs Altyn or Antiklesch are used.

Plum moth one color

A small butterfly with thin gray wings belongs to the family of small moths - the size of adult individuals barely reaches 4 mm. Mass flight occurs twice a year, the first occurs in April-May, the second at the end of June. Like all other moths, butterflies lay eggs on the underside of the leaf blade. The period of embryo development depends on weather conditions. Caterpillars feed on leaf parenchyma, gnawing tunnels in the blades called mines. Violation of the integrity of the foliage leads to wilting of the tree.

Pupation of the single-colored plum moth occurs in the upper soils

layers, so destruction requires mandatory digging not only of the tree trunk circles, but also of the entire area.

Pocket thorn moth (Parornix torquilella Z.)

Damages thorns, plums, cherry plums. Small, rarely medium-sized butterflies with a wingspan of 4.5 - 21 mm and rather large round eyes. Caterpillars overwinter in cocoons, mainly in folds of bark or in fallen leaves under trees. Pupation occurs in April - early May. The moth's flight lasts until the end of June. The caterpillar is located in a mine on the underside of the leaf. Having reached the fourth instar, it leaves the mine, bends the edge of the leaf, firmly attaches it with a web on the underside and forms a pocket in which the leaf skeletonizes from the inside. During the period of its development, the caterpillar can make 3 - 5 pockets. Moths are especially harmful in years with dry and hot summers.

Moth

Control measures. Spraying with Lepidocide or Bitoxibacillin during the growing season against each generation of the pest at intervals of 7 - 8 days, working fluid consumption - 800 - 1200 l/ha. Treatment with Fufanon, EC or Kemifos, EC - during the growing season, consumption - from 2 to 5 liters per tree.

Goldentail (Euproctis chrysorrhoea)

An adult insect is a butterfly with a snow-white wingspan of up to 4 cm. Females have a golden, hairy pad at the end of the abdomen. The grayish-black caterpillar grows up to 3.5 cm. It is poisonous and can cause skin irritation, so you need to wear gloves when collecting pests.

Caterpillars overwinter in web-covered nests of leaves in the forks of branches. The butterfly season begins in mid-summer. Eggs covered with golden hairs can be seen on the underside of leaves, branches and trunks. The caterpillars emerging from the eggs feed on the pulp of the leaves, practically scraping out the leaf blades.

Lacewing butterfly

Control measures. Removing winter nests of caterpillars from trees, shaking off insects, destroying oviposition. Insecticides used include 10% solutions of Karbofos, Benzophosphate and Antitlin. Among biological preparations, Lepicid and Dendrobacillin are used. In home gardens, during the period of bud break and when caterpillars emerge from eggs, trees are treated with infusions of tobacco, chamomile, and wormwood.

Plum insect pests: descriptions, photos and methods of combating them

It's hard for me to imagine a garden without a plum.
This is one of the most popular and unpretentious fruit trees I know. When my summer cottage remained abandoned for many years, plums were the only ones that continued to bear fruit. So preserving and caring for them means a lot to me. In this article I want to share with you the knowledge I gained while restoring the garden. Although plums are very hardy, they are susceptible to diseases and pests. If you want to grow strong, healthy trees and get a bountiful harvest, you need to be aware of the dangers so you can recognize them and eliminate the threat in time.

Zlatki

Black borer (Capnodis tenebrionis L.) is a very dangerous pest, mainly damaging young trees of stone fruit crops. The larva of the borer is yellowish-white, up to 70 mm long, with a greatly expanded prothoracic segment. The beetle is up to 29 mm long, its pronotum is densely punctured and covered with a white waxy coating.

Black borer

Larvae of different ages overwinter in tunnels made in the roots of fruit trees, and beetles overwinter in the surface layer of soil. The emergence of beetles from the soil continues from June to September. In the process of feeding, the beetles gnaw leaf petioles, gnaw out buds and gnaw the young bark of shoots. During her life, one female lays from 200 to 2500 eggs in folds of bark in the area of the root collar and on the soil near the trunk. The development of the larvae continues for two years - they gnaw out wide tunnels filled with brownish flour under the bark of the roots. Feeding on the cambium and root wood, the larvae cause damage that leads to weakened growth and subsequent death of young trees. Having completed development, the larva pupates in the spring in the area of the root collar.

Copper gold

Adult copper borer beetles (Perotis lugubris) gnaw young bark and gnaw leaf petioles. The length of the beetle is 13 - 27 mm. The larva overwinters. A generation develops over two years. In July-August, female copper borers lay eggs in cracks in the bark of young trees near the root collar. The emerging larva penetrates the bark and wood. She gnaws out passages under the bark, filling them with fine sawdust, like flour. The larva prepares the pupation chamber in the fall and spends the last winter in it. Pupation occurs in the spring. In the south, it is common for adult beetles to overwinter in pupation chambers or outside them, in the litter. Adult beetles emerge from their pupae in the fall.

Control measures. When planting stone fruit orchards and nurseries, it is necessary to carefully remove all remnants of tree and shrub roots from the soil, since borer larvae may remain in them. The chemical method of pest control consists of timely spraying of crowns, trunks and soil under trees with pyrethroids, organophosphorus compounds, neonicotinoids

Why are plums bleached?

Inexperienced gardeners often ask the question why it is necessary to whiten trees if no one does this in industrial gardens or nurseries. Indeed, this is how it really is.

In extensive gardens or nurseries, trees grow densely. This provides the crowns with natural shading. A dense garden creates its own microclimate with stable temperatures and air humidity.

In small gardens, trees are usually located far from each other. Of course, no microclimate can arise in your garden. Seedlings initially find themselves in extreme conditions for them. They are open to all winds, cold, heat. By and large, they are weakened, and such plants are most susceptible to pests. Applying a layer of lime mortar just protects trees from the invasion of harmful insects.

It is worth bleaching not only young plums, but also old ones. Lime mortar, with its properties, not only protects trees from the penetration of harmful insects from the soil, but also protects them from sunburn, to which young trees are so susceptible. In addition, it helps strengthen the cortex.

Seedlings and very young trees should be whitened with pure lime mortar without any additives.

Plums that are 5 or more years old should be whitened with lime mortar with the addition of clay, chalk and copper sulfate. In order for the whitewash to last longer, you need to add a little casein glue or PVA to the solution.

You need to bleach plums from the very bottom of the trunk to the first branches. However, it would not be superfluous to whiten the bases of the branches. The main thing is not to whiten the kidneys.

Whitewashing of plum trees should only be done in dry and cool weather. Plums are bleached both in autumn and spring. Autumn whitewashing is done after the leaves fall, but before the onset of the first frost. Wait until the autumn rains stop.

Spring whitewashing is carried out before the sap flows and the buds begin to swell. Some gardeners do this immediately after the snow melts.

Autumn whitewashing

Before starting whitewashing, you need to spread a film under the plum. This is done to ensure that the lime solution does not get into the soil. After this, dead areas of bark and, if any, mosses and lichens must be carefully removed from the tree trunk and the bases of the branches. If there are damaged areas on the trunk or branches, they need to be treated with garden varnish. After this, you can proceed directly to whitewashing.

If you decide to use acrylic paint instead of lime mortar, then you first need to treat the surface to be whitewashed with an aqueous solution of copper sulfate. The solution is prepared at the rate of 100 grams of vitriol per 10 liters of water.

After completing the work, the film, of course, needs to be removed.

Spring whitewash

The volume of necessary spring work is exactly the same, in the same way as for the autumn whitewashing of plums. True, the whitewash needs to be applied in a thicker layer, so that there are no untreated areas of the bark left.