O. V. Abashkin, Yu. A. Masyuk, D. V. Abrosimov, O. A. Aleksyutina, V. I. Chernikov
In recent years, our country has seen an increase in the number of herbivorous bugs, including those species that are classified as potato pests. In addition to causing direct damage to plants, these species are also carriers of pathogens of viral diseases, in particular potato spindle tuber viroid and mosaic leaf curl virus.
Potato tuber spindle viroid (Potato spindle tube viroid). The disease is characterized by a decrease in the number of shoots, shredding of leaves, and curvature of the leaf surface. The shoots and petioles of the leaves are located at a more acute angle. The terminal lobes of the upper tier are strongly deformed, bent to the sides, forming a sickle shape, the leaves become ivy-shaped due to the curvature of the veins and the contraction of the marginal leaf lobules. Affected bushes turn pale, become chlorotic, and the tops acquire an anthocyanin color. Affected tubers elongate, take on a spindle-shaped shape, and sometimes deep cracks form on them. Mature tubers develop round, slightly protruding spots from 0.5 to 2.5 cm in diameter; during storage, the spots darken, their surface hardens and is pressed into the tubers. In varieties with anthocyanin coloring (purple tubers), when affected by viroid, the color intensity of the tubers decreases. The disease leads to significant crop loss.
Mosaic virus ctwisting the top leaves of the potato also known as: K—mosaic leafroll virus, M—potato virus, Potato paracrincle virus Salaman, Potato virus M (PVM), Potato virus 7 Smith. It is distinguished by characteristic symptoms: wavy edges of the upper leaves, resembling boats. This symptom is most pronounced during the budding period. By the end of the growing season, the symptoms of the disease weaken or disappear completely. Often the disease exists in a latent (latent) state and then it can only be detected using a specialized method - enzyme-linked immunosorbent assay (ELISA). Sometimes the disease is combined with other viral diseases (potato viruses S and X). Sick plants reduce yield (by 25-40%) and starch content of tubers (by 2-3%). In seed plots of elite potatoes, diseased viroid and viral plants are removed during phytosanitary cleaning.
Bedbugs (hemiptera or hemiptera) is a large suborder of insects with more than 40 species.
A characteristic feature common to all representatives of this order is their piercing-sucking mouthparts (the proboscis is jointed, extending from the front of the head). The habitats of bedbugs are extremely diverse: insects can be found at home (bed bugs), in bodies of water (tropical water striders living on the surface of the ocean, and freshwater bedbugs, the larvae of which prey on fish fry), in the sand, forests, etc. Many types of bedbugs bring great benefit by sucking and eating pests of agricultural plants, including potatoes. But herbivorous bugs can cause great harm to the farm.
Bugs found on potatoes
Various types of herbivorous bugs are found on potato plants: mustard bug (Eurydema festiva L), green bug (Nezara viridula L), green beet bug (Orthotylus flavosparsus C), Norway bug (Calocoris norvegicus Gmel) - in addition to feeding on plant food, this species destroys insect larvae - including the Colorado potato beetle; meadow bug (Lygus pratensis L), alfalfa bug (Adelphocoris lineolatus Goeze), green wood bug (Palomena prasina L), striped bug (Graphosoma italicus Mull), beet bug (Poecilos cytus - Polymerus cognatus Fieb), bread bug (Trigonotylus ruficornis Geoffr). Representatives of the horsefly family most actively transmit pathogens of plant viruses.
Slepnyaks or Miridae – insects of small size, usually elongated, with soft covers. They feed mainly on plant sap. In total, there are over 650 species in the family - this is more than half of the species of bedbugs in the domestic fauna. About 50 species harm agricultural crops. Some species carry pathogens of viral plant diseases. Several species from this family are the most harmful.
Potato bug (Calocoris norvegicus Gmel) - an insect of pale green color, six to eight mm in length. The antennae are long and thread-like. The eggs are yellow and up to two mm in diameter. Found on cabbage, potatoes, roses, and chrysanthemums. Larvae (nymphs) and adult insects suck the juice from leaves, inflorescences, and flowers. Necrotic spots appear on damaged areas of leaves. The leaves wrinkle and the stems become deformed. In mid-latitudes, the bug produces two generations per year. Females lay eggs in the stems of woody plants, where they overwinter. Nymphs hatch from eggs in the spring and feed on plant sap.
Klopp meadow or field bug (Lygus pratensis L). Body length 5-7 mm. The body is short oval, the color ranges from greenish-yellow to dark brown. The head has three dark lines, the larvae are yellow-green, with five black dots on the upper side of the body (two on the pronotum, two on the mesonotum and one on the upper side of the abdomen). Distributed everywhere except the tundra zone. Adult bedbugs overwinter under plant debris in tree plantations. The exit from shelters occurs soon after the snow melts. In spring (April - May), the meadow bug feeds mainly on winter crops, then migrates to vegetable seedlings, sugar beets and forage grasses, after which it moves to potato plantings. Females lay eggs in the succulent tissues of the petioles or veins of the leaves of many plant species. The embryonic period lasts about 10 days. The larvae develop in 25–35 days. In the steppe zone in the south of Ukraine, in the Lower Volga region and in the North Caucasus, the pest gives three to four generations, in the forest-steppe zone - three generations, in the central zone of the European part of the Russian Federation - two generations, in the northern regions one or two generations. The flight of the first generation in the central part of the Russian Federation is observed in late June - early July, the second generation - from the second half of July to the end of August. Meadow bugs are very mobile, often flying in search of suitable food plants. Leaves eaten by the pest curl, affected plants branch abnormally and are stunted in growth. Damaged buds and flowers fall off. In some years, bedbugs cause significant damage to agricultural crops, the true extent of which cannot always be assessed by eye, since pests also serve as carriers of viral infections.
Alfalfa bug ordinary or horsefly alfalfa (Adelphocoris lineolatus Goeze). Body length 7.5 – 9.0 mm. The proboscis extends beyond the middle of the prothorax. The upper part of the body is covered with silvery hairs. There are two to four black spots on the pronotum. It is found in the European part of Russia - in the north to Karelia, Kirov and Sverdlovsk regions, in the forest and forest-steppe zones of Siberia and in Central Asia - up to 62о With. w. Eggs laid in the stems of perennial legumes overwinter. Postembryonic development of the bug lasts 14 – 60 days at a temperature of + 15 – 20оC. Optimal temperatures for pest development: + 20 - 30оC. Bedbug larvae molt four times and develop, depending on the temperature, from 14 to 34 days. In Ukraine they give two, and in Central Asia - three generations.
At temperatures below + 15оWith the development of eggs in females, the development stops. It was noted that in the southern part of the steppe zone of Ukraine and in the southeast of the European part of Russia, high temperatures cause a decrease in the number of bedbugs. The pest population also decreases at low summer temperatures.
On potatoes, alfalfa bugs are most numerous in the southern regions. Basically, pests feed on the generative organs of plants, which causes the buds and flowers to dry out and fall off.
Klopp field (meadow (Lygus pratensis L)). The insect is 6.0 – 6.5 mm in length. The body is flat, elongated. The color is grayish-green or dark brown. The field bug is polyphagous. It feeds on many herbaceous plants. Adult insects (imago) hibernate and wake up soon after the snow melts. In April - May, bugs feed on winter crops, then move on to seedlings of vegetable plants, sugar beets, forage grasses, etc., after which they appear on potatoes. The species is distributed everywhere except in the tundra zone. In the central zone of the Russian Federation, the bug gives two generations (generations), in the south of Ukraine, in the Lower Volga region, in the North Caucasus - three to four generations. In the middle zone, first-generation bugs fly at the end of June, early July, and second-generation adults fly from the second half of July to the end of August. The activity of flying bugs is high, which contributes to the spread of viral plant diseases they carry (such as potato spindle tuber viroid or potato gothic virus, potato mosaic viruses, stolbur of nightshade plants), mainly in the south of Russia.
Klopp beet or tolop brown beet (Poeciloscytus, Polymerus cognatus fever) or Beet horsefly. Length 3-5 mm. The body is covered with silky hairs; on the anterior edge of the pronotum, a cervical ring is separated by a deep groove. The color is variable, variegated, usually brownish-yellow. The apex of the scutellum is always yellow. The forewings are brownish-yellow with a black wedge-shaped spot in the center. The membranes are smoky-brown, the triangle between the membrane and the rest of the elytra is red-brown. The larva is green with red eyes, up to 3.3 mm in length. There are two black dots on the shield. There is a black round spot on the dorsal side of the abdomen. The eggs overwinter on various plants (bindweed, quinoa, alfalfa, pigweed, rapeseed, etc.). In the spring, bug larvae develop on these plants. Adult insects emerge and fly in late May – early June. They scatter over a radius of up to three kilometers and move on to various crops, including potatoes. The species mainly damages crops and beet plantings. Females of the pest lay eggs in the tissue of the veins and petioles of leaves, in the upper tender parts of the stems, placing them in groups of several pieces, closely pressed to each other. One female lays from 70 to 240 eggs. Bedbug embryos, depending on temperature, develop within 5-15 days. The larvae feed and develop for 1 – 1.5 months. In the central part of Russia, the bug gives two generations, in the southern regions - three to four generations. When beet leaves become coarser and become unsuitable for feeding bugs, they move to quinoa, alfalfa, wormwood, etc. plants, where they live until late autumn and lay eggs that remain for the winter. When feeding on beets, bugs suck the juice from the leaves, causing them to curl. Damaged leaves subsequently turn brown and dry out. Then the pests move on to the more tender central leaves, as a result of which the plants stop growing or dry out completely. Flower buds dry out and the resulting seeds turn brown. When damaged by bugs, the weight and sugar content of beet roots drop, and the testes produce small seeds with low germination. Beet bugs transmit mosaic viruses. The bug is common in forest-steppe and steppe areas of beet growing. It is noted as a serious pest of beets in steppe regions (Central Asia, Altai Territory, Eastern part of the steppe zone of Ukraine, Voronezh region, Krasnodar Territory, Western Siberia). Polyphagous. The main food plants - in addition to potatoes and beets - are vetch, peas, mustard, hemp, flax, alfalfa, sunflower, soybeans, lentils, sainfoin, etc. Beet bugs cause especially great harm in dry years, when after wild vegetation dries out, the bugs migrate from nearby fallows and wastelands for crops of cultivated plants. Adult bugs and larvae suck the juice from the leaves, and at first their activity is invisible. On the fading leaves you can only see transparent drops of dried sap. Dying plants turn black and dry out, and the sprouts become thread-like. Bed bugs transmit pathogens of viral diseases of potatoes and sugar beets.
Natural enemies of herbivorous bugs: ladybugs, pseudoscorpions, some species of centipedes and ants.
Fight
- Removing crop residues from the field.
- Early autumn plowing.
- Weed control in boundaries and areas surrounding agricultural crops.
It is necessary to carefully mow and remove wild plants from the field, and cut alfalfa low in order to remove overwintering bug eggs from the fields.
Before spring harrowing, wild herbs must be carefully collected and burned.
It is not recommended to plant potato plants near crops of perennial grasses.