Colorado potato beetle: description of a merciless pest of potatoes and not only

Colorado beetle (Leptinotarsa ​​decemlineata) belongs to the leaf beetle family, the beetle order. This is one of the most malicious pests of the garden and vegetable garden, bringing significant damage.

Did you know? For its color of the five black stripes on each of the two elytra, the Colorado potato beetle got its name, which literally means ten lines in Latin.

The appearance of the Colorado potato beetle

Many people know what a Colorado potato beetle looks like - its tight-fitting, yellow-chitinous elytra of orange-yellow color has five black stripes each; This combination is very recognizable in the green garden. Females are slightly larger and heavier than males. The body of the imago is oval, in length can reach from 8 to 15 mm, in width - approximately 7 mm. Abdomen orange color with black spots. The structure of the upper part of the body of the Colorado potato beetle has a convex shape, the bottom - flat. Webbed wings are well developed and allow beetles to fly long distances. The head of the beetle is much smaller than the body, located almost vertically and slightly retracted, rounded shape.

The beetle has three pairs of legs. Thin legs of the beetle are weak, with claws for insect movement. The eyes are located on the sides, black, have the shape of a bean. Near the eyes there are antennae, which consist of ten segments.

The larva of the Colorado potato beetle is about 1.5 cm long, with a small black head. The trunk of the brown larva, which later becomes pale pink, has two rows of dark small dots on the sides.

The eggs of the pest are bright orange in color; the female lays up to 60 small eggs in one laying.

Important! When the Colorado potato beetle is destroyed, one-half of the green mass of the potato bush, its yield will fall by a third.

Where did the Colorado potato beetle come from

The origin of the Colorado potato beetle begins with Mexico, from the north-eastern part of it, from where it spread to the United States. In 1859, the pest caused colossal damage to potato plantations in the state of Colorado, after which it was named the Colorado potato beetle. It is believed that the pest was brought to Europe in the 1870s by cruise ships plying the Atlantic. The beetle successfully adapted to life in France and England and spread to the rest of European countries.

In the 1940s, when the Colorado potato beetle first appeared in the USSR, collective farm workers and quarantine brigades tried to save land from it, but the pest was intensively moving across the entire territory of a huge country. Suitable weather conditions, large crops of the beetle and its larvae, and its fecundity had a favorable effect on the settlement of the harmful insect. Trying to answer the question of where the Colorado potato beetle came from in Ukraine, many biologists agree that the pest flew in large quantities from the territory of Hungary and then Czechoslovakia on a windy and warm spring, when the air masses contributed to its extensive and rapid spread.

What eats colorado beetle

The Colorado potato beetle is gluttonous, especially since in the gardens it always grows enough what it eats - solanaceous crops: potatoes, tomato, eggplant, sweet peppers; the pest also eats tobacco, nightshade, woodworm, henbane, physalis and petunia. Larvae and imago feed on young shoots, flowers and leaves of plants, and in autumn time - on potato tubers. Usually, the beetle settles in a small area of ​​plantings, eats the ground part of one plant, after which it moves to the other, and the affected cultures dry out and gradually die. Since the pest actively propagates and rapidly spreads, and the leaves and stems of plants are eaten by both adults and larvae. The damage from the Colorado potato beetle is enormous and can be calculated in hectares of cultivated plantations.

Did you know? Adults of the Colorado potato beetle can sleep in the ground for up to three years, after which they can appear on the surface - this is how they survive the hungry years.

Reproduction of the Colorado potato beetle

In the spring, three to five days after the emergence of the Colorado beetles on the soil surface, the process of their reproduction begins, which lasts until the autumn. Beetles mate, females place eggs in the amount of 20-70 pieces in secluded places on the back of the leaves or in the branching of the shoots. After 7–20 days, the larva hatch from the egg, which then passes through the pupation stage, and at the beginning of summer a young generation of adult pests appears. The larvae that have just emerged from the egg have a length of up to 3 mm and already feed on succulent foliage. The life cycle of this pest will be discussed in more detail in the next paragraph of the article. One female beetle per season is able to lay up to a thousand eggs.

The most favorable conditions for reproduction and development of the young generation of the pest are temperatures of + 21 ... +23 ° С and humidity at the level of 70-80%. At temperatures below +15 ° C reproduction does not occur.

The life cycle of the Colorado potato beetle

If in the fall the female has had time to fertilize, in the spring immediately after hibernation she will lay eggs, of which after 2-3 weeks larvae appear. A characteristic feature of the development of the larvae of the Colorado potato beetle are four age categories, each of which ends in a molt. In the first stage of age, the gray-colored larva is densely covered with hairs, its body reaches a length of 1.6-2.5 mm, and feeds on the tender flesh of young leaves. In the second stage of age, the larva is slightly pubescent with hairs, its length is 2.5-4.5 mm, it feeds on the soft part of the leaf plate, eating it before skeletization. The third stage of the larvae passes in brick color, the body reaches 5-9 mm. The fourth stage of age is the length of the larvae is 10-15 mm, the color is from yellow-orange to yellow-red hue, at this stage the pest is the most voracious before hatching in the imago.

Important! The main damage to agricultural plantations is caused by the larvae of the Colorado potato beetle, which require a lot of nutrients for their development.

The food of the larvae of the Colorado potato beetle is very intensive, with almost all the foliage of the plant being destroyed. After two or three weeks, the larva dips 10-15 cm into the soil for pupation. Depending on the temperature of the earth, the larva pupates within 10-18 days. An offspring pupa is orange or pink, its length is about 9 mm and width is 6 mm, after a few hours its color changes to brown. During pupation in the autumn months, the beetle remains to winter in the soil, not crawling to the surface. If the transformation into adult individuals occurs in the spring-summer period, the beetles creep out to the surface.

In the first 8–21 days of life, the imago actively feeds, storing nutrients that will be useful to it in its further settlement and long-distance flights. An adult beetle is able, with the help of the wind, to travel several tens of kilometers from the place where the larvae hatch from the egg. In addition to hibernation, beetles can reduce activity during the dry or hot period, falling into a long sleep for up to 30 days, after which its activity continues. The life span of the Colorado potato beetle is 2-3 years, during which it periodically falls into a long diapause.

Where and how does the Colorado potato beetle winter

Where the Colorado potato beetle lives in the winter - this question interests many gardeners who are fighting this survivable pest. After an adult beetle appears from the pupae in the fall, it remains to winter until the spring in the earth’s thickness. Adult beetles in the autumn are buried in the ground for the winter, and they can survive freezing to -9 ° C. The wintering of the pest takes place in the soil at a depth of 15-30 cm, in the sandy soil the beetle can go deeper to a depth of half a meter. A small number of beetle populations in severe frosts may die, but, as a rule, these insects tolerate the winter well, being in a long hibernation. When the soil warms up to 14 ° C and the air temperature is above 15 ° C, the beetles begin to wake from hibernation and gradually creep out to the surface of the earth in search of food.

Did you know? The female, who laid eggs, endures wintering worse, because she does not store the necessary amount of fat reserves.

False Potato Beetle

Exists in nature mock potato beetle (Leptinotarsa ​​juncta), which is slightly smaller than Colorado and differs from it in color. The length of the false beetle usually does not exceed 8 mm, the elytra are colored in alternating stripes of white, black and yellow, the legs are dark in color, and the abdomen is brown in color. The false beetle does not harm agriculture, as it prefers weedy wild plants of the nightshade - Caroline and bittersweet, as well as Physalis. A false beetle does not eat potatoes and does not use its tops for breeding, like other tasty cultures for the Colorado potato beetle.

Watch the video: С этой защитой ЖУКА НЕ БУДЕТ всё лето! (March 2024).