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Colorado Potato Beetle - How To Deal With It
Colorado Potato Beetle - How To Deal With It

Video: Colorado Potato Beetle - How To Deal With It

Отличия серверных жестких дисков от десктопных
Video: A Couple Organic Methods To Deal With Potato Bugs / Beetles 2023, February
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Colorado beetle
Colorado beetle

The most dangerous pest of potatoes - the Colorado potato beetle - continues to thoroughly master the plantings of this crop in the North-West region. Appearing in the 20s of the last century on the European continent and moving, on average, 50-80 km a year, regardless of state borders, it reached us several years ago.

In the practice of our potato growing, a situation has already developed that the population leaving for the winter is quite numerous and is no longer completely controlled by us. There are several reasons for such a rapid spread, wide dispersal and increased harmfulness of the Colorado potato beetle. It is very hardy and easily adapts to a variety of climatic and environmental conditions. Adult insects are very tenacious. So, when unfavorable conditions occur, they live without food for several months (some individuals in the soil up to 3 years). Beetles do not die when immersed in water for 10 days, while freezing - within 2 days. They can be transported to new areas with vegetables, soil, containers, carried by the wind.

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Colorado potato beetle lifestyle

In order to successfully resist the Colorado potato beetle, we recall its lifestyle in order to be able not only to identify it in a timely manner, but also to process the inhabited bushes in time. Probably, every potato breeder can already recognize this phytophage and its larvae. The beetle has an oval body, from above it is convex, from below it is flat, red-yellow in color, 6-7 cm in size. The beetles winter more often at a depth of 20-30 cm, but in some years they deepen to 0.8-1 m. Depending on physiological fitness and environmental conditions, up to 10-90% of wintering beetles die. The successful wintering of these pests is determined, as a rule, by how much they managed to accumulate a fatty body to wait out this unfavorable period.

From the place of wintering, beetles get out to the surface of the soil when it warms up to 13 … 15? C (air - up to 22.. 25? C), in our area this happens in early June. As a rule, the beetle hibernates in the place of the site where it fed on agricultural crops. The active release of the pest is facilitated by good soil moisture and warm rains, but under unfavorable conditions this process can take up to 2 months (up to 50% of individuals), which leads to an extension of the time they lay eggs and the appearance of larvae.

If a pest has not yet been noted on the site, then from the moment potato shoots appear or after tomato and eggplant seedlings are planted in the ground, a thorough examination of the plants is carried out at least once a week. Mass flowering of a dandelion can serve as a signal for starting observations.

Sometimes the emergence of the beetle is earlier than the appearance of its main forage plants from the Solanaceae family. Then the beetle can be found on a number of flower crops. You can't let him eat there - you need to urgently collect and destroy it, otherwise the beetle will then move to cultivated plants. In the absence of a fodder base in the form of potatoes or tomatoes, he switches to feeding and laying eggs on peonies, spirea, echinacea and lilies. Moreover, on lilies, he can eat not only leaves, but also buds.

Beetles prefer to settle on young potato plants and on solanaceous seedlings, usually eating leaves up to the petioles. A few days after the settling of the plants, the female lays on the lower part of young leaves, usually up to 500-600 yellowish eggs in groups of 20-25 pieces. Therefore, having found the first beetles on the potato bushes, be sure to check the leaves of the plants to see if there are any egg-laying on them. This will facilitate subsequent pest control or manual collection of larvae. In about 7-8 days, larvae hatch from eggs, which develop, depending on weather conditions, for 20-25 days.

The larvae have 4 instars. In the first they are gray, in the second they are red, in the third and fourth they are orange. Starting from the upper leaves and ending with the lower ones, the caterpillars devour the bush completely, usually leaving only bare stems. Having destroyed the tops of one plant, they move to the next. After feeding, they go to pupate in the soil (to a depth of 7-15 cm). Under favorable conditions, young beetles appear after 7-12 days.

According to experts, the most voracious are the larvae of the 4th age and especially the young (hatching) beetles, which need to gain a fatty body for the upcoming wintering, so they are able to eat even the petioles and stems of potatoes. In hot weather or during night and morning cold hours, beetles burrow into the soil (2-4 cm) or hide in dense weeds. Usually, in the conditions of our region, the pest produces only one full generation.

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Colorado potato beetle control

Scientists have found that among the species composition of entomophages, carnivorous ground beetles, ants, common lacewing, coccinellids, spiders, are exterminators of eggs and larvae of the Colorado potato beetle, and the first three groups are the most active. It is imperative to fight the Colorado potato beetle, since it causes great harm to the potato crop, but its success depends on the timeliness of its identification. In a short period of time, beetles and their larvae, feeding on the leaves and stems of potatoes, can destroy the entire bush, as a result of which the yield is sharply reduced or completely absent.

In the fight against the Colorado potato beetle, many methods and means have been tested, which often turn out to be insufficiently effective or laborious. If the area of ​​potato planting is small (3-4 hundred parts), manual harvesting is used, trying to identify the first individuals, which facilitates the subsequent fight against larvae, therefore it is important to systematically remove and destroy beetles and their egg-laying.

If, when protecting plantings from the Colorado potato beetle, folk remedies are used - solutions of plant origin, then it must be borne in mind that they often turn out to be ineffective. Even the use of microbiological preparations requires at least 5-6 treatments, which does not always suit gardeners. In this regard, it is often necessary to use chemical insecticides, which, of course, have a detrimental effect on the beneficial entomofauna and are somewhat dangerous for humans. We have to admit that these drugs do not destroy all beetles, but only temporarily restrain their numbers. The surviving individuals reproduce relatively quickly, and their offspring, in addition, often acquire immunity to this drug.

It is preferable to carry out chemical treatments during the period of mass appearance of young larvae; in the older (third and fourth) instars (especially before leaving for pupation) they are more stable. Plants are sprayed with a solution of a drug from among those approved for use in the private sector (arrivo, deltacid, decis, karate, kinmix, regent, sonnet, arrow, fas, fenax, phosphatecide, cymbush, citkor, cipershans, sherpa, sumi-alpha, fury, aktara - the last three are the most highly effective), taking into account all the precautions and the waiting time (from the last treatment to the beginning of harvest). If next to the potatoes there are beds with vegetable plants or fruit and berry crops, then they are protected with plastic wrap before spraying.

If a gardener looks closely at his potato plantings, he may notice that the Colorado potato beetle prefers some bushes to others (even of one variety). On some bushes, there are many beetles and egg-laying, and nearby there are plants without insects or with a low number. It was noticed that on powerful plants with strong, dense stems, with the color of leaves characteristic of this variety, there are noticeably fewer pests. Their taste does not suit him: he sits on them reluctantly and lays significantly fewer eggs.

But others, with obvious symptoms of diseases (more often affected by bacteriosis or viruses) - weak, with thin stems, slightly leafy, with dull leaves - are preferable for the beetle. You can joke that the beetle serves as a kind of "indicator" and allows you to accurately determine under which plant there will be healthy tubers, and under which - sick, degenerate, unsuitable for further cultivation. This phenomenon tells the gardener that it is important to plant potatoes with well-vernalized healthy varietal tubers as early as possible, and to carry out hilling and feeding in a timely manner so that the plants develop faster.

After harvesting, discarded, chopped or small tubers often remain on the soil surface. Deprived of the opportunity to feed on green tops, the Colorado potato beetle begins to eat them, therefore, its accumulations on abandoned tubers are not uncommon. It turns out that the gardener himself provides the pest with the opportunity to feed on the tubers and berries of potatoes left after harvesting, as well as on other remains of nightshade crops that have not lost their juiciness. In favorable weather, insects concentrate on them until late autumn, leaving into the soil just a few days before the onset of frost.

In addition, the Colorado potato beetle is also considered a carrier of the noxious potato nematodes.

Potato varieties resistant to the Colorado potato beetle

To date, potato breeders have not managed to create varieties that would combine both resistance to the Colorado potato beetle and high taste. But there are several varieties that are relatively resistant to the Colorado potato beetle. This is a mid-late variety Zarevo (Ukraine) with a pink, mesh skin, white pulp, with a starch content of 18-24%, with increased resistance to common scab and relative to late blight; yield up to 550 c / ha. Late-ripening variety Lasunak (Belarus) with white skin, yellowish-white flesh, starch content of 18-22%, with relatively high resistance of tubers to late blight and viral infection, very high - to rhizoctonia disease.

Medium early Svitanok Kiev (Ukraine) with pink tubers, creamy pulp, starch content of 15-22%, has a long dormant period, is susceptible to late blight and viral diseases, has an increased regenerative ability when damaged by the Colorado potato beetle. The varieties Stolovy 19, Nikulinsky and Peresvet are also characterized by increased resistance, however, there is information that the latter is characterized by an increased concentration of alkaloids.

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