Contents
Gardeners have two serious enemies that can nullify all efforts to grow a crop. One of them specializes in tops, the second in roots. Both pests are beetles. And the second is much more dangerous than the first: the Colorado potato beetle. Although the Colorado potato beetle has very few natural enemies on the Eurasian continent, its distribution is limited by climatic conditions.
The second beetle, numbering more than 10 thousand species, united by the common name “nutcracker”, is distributed throughout the world. It was found even at an altitude of 5 thousand meters above sea level.
The name “clicker” beetles received for the ability to jump. In this case, the insect makes a characteristic sound: a click. On a note! Thanks to the ability to jump, it can be determined that it was the nutcracker that was trapped in the garden.
It is enough to turn the beetle on its back. If it is a clicker, then it will return to its normal position with this characteristic click.
The ability to identify the click beetle is not out of place, since, unlike the Colorado potato beetle, click beetles are not cosmopolitan, and each species lives in its own range. Therefore, the appearance and size of clickers are very diverse. Beetles can be from 1 mm to 6 cm. They only have in common the ability to jump, which they use to avoid danger, and the characteristics of larvae, nicknamed “wireworms”.
Nutcracker hairy
Click beetle
Jamaican bioluminescent click beetle
The biology of click beetles is very poorly understood. And if relatively much information has been accumulated about the Eurasian click beetles, then little is known about the American ones, and practically nothing is known about the tropical ones.
It has been established that the beetles themselves are not dangerous to plants, their larvae do harm. Moreover, a significant part of click beetles, more precisely, their larvae, are serious pests that inhabit cultivated lands. While the other part are predators, hunting in the ground for other living creatures living in the ground.
Click beetle larvae are no less diverse in terms of size and color. But the larvae also have common features: a hard chitinous shell and a worm-like shape. Thanks to this appearance, the larvae are very similar to a piece of wire, which is why they got their name.
A real scourge for gardeners is the larvae of three types of click beetles.
Nutcracker dark
Nutcracker sowing striped
steppe nutcracker
In addition to them, there are several more species of click beetles, whose larvae can seriously damage crops.
Description of the wireworm with a photo and how to deal with the wireworm
To understand what the wireworm of each species of click beetle looks like, one would have to study entomology.
The wireworm of the dark nutcracker reaches 2,5 cm in length and has a dark yellow color of the chitinous cover. With a high degree of probability, the wireworm of the dark click beetle is in the photo.
The wireworm of the steppe nut beetle is 3,5 cm long, brown-red.
Wireworms of the striped click beetle are up to 2 cm long and not more than 2 mm in diameter.
At the same time, the larvae of the same click beetle can be of different ages and vary in size, like wireworms in the photo.
They have a very hard chitin in common, which makes it almost impossible to crush the wireworm.
The fight against the wireworm for the gardener is even more important than the fight against the Colorado potato beetle. Colorado can be harvested by hand, the wireworm is not visible underground. In addition, the colorado eats only nightshade plants and does not touch others. The wireworm spares nothing. It drills any root crops and eats up the roots of any plants.
Colorado, eating foliage, reduces the yield and size of tubers. But they can be stored potatoes. Root crops perforated by a wireworm are no longer suitable for long-term storage. Yes, and for food is no longer very suitable because of the internal passages.
Almost all gardeners are trying to find a reliable remedy for the wireworm, since if the female nutcracker laid eggs in the garden, then the entire garden will be infected and for more than one year. Even if the wireworm has disappeared, this may mean that the larvae have pupated and, after a few years, adult beetles will emerge from the pupae, which will again lay their eggs in the garden. One female can lay up to 200 eggs per year.
Wireworm control methods
In agronomy, there are two ways to deal with it: agrotechnical and chemical, that is, with the use of insecticides.
Chemical method
When using the chemical method, the soil is treated with wireworm preparations. The method is expensive and infects the earth with pesticides that kill not only the wireworm, but also beneficial insects living in the soil. First of all, because of the high cost, the chemical method is not well suited for homeowners.
Nevertheless, if things are really bad and the wireworm has flooded the site, you can use the Aktara preparation, which is bred according to the instructions, and they spill the places of future plantings with them, and also soak the tubers in it. The drug is guaranteed to destroy all living things in the soil, including beneficial larvae and insects.
You can sow the plot with corn or barley seeds pickled in Aktara. This must be done before planting the main crop.
In greenhouses where the use of any chemicals is prohibited, pheromone traps are used for mature beetles.
Application of nitrogen fertilizer
This method of struggle can also be attributed to chemical. It is proposed to treat the soil with ammonia fertilizers. It is very problematic to use this method in a summer cottage, since a mandatory requirement when using this method is the incorporation of ammonia water into the soil to prevent evaporation of ammonia.
It is believed that after using ammonia fertilizers, the wireworm tends to leave the treated area.
Agrotechnical methods
All these measures are designed for several years. A one-time action for the destruction of the wireworm with agrotechnical methods cannot be achieved.
Agricultural practices include:
- deep autumn digging of the site. The soil is dug up to the maximum depth just before the onset of frost, so that the larvae do not have time to hide again. During frosts, the wireworm freezes;
- thorough cleaning of the roots of weeds. The rhizomes of wheatgrass and barnyard are the favorite food of wireworms, therefore, when digging the soil, it is necessary to carefully remove the wheatgrass roots, even 1,5–2 cm long;
- surface loosening of the soil in late spring – early summer. Under the sun’s rays, the eggs of click beetles die;
- 2-, 3-field crop rotation. After potatoes, legumes are sown, among other things, enriching the soil with nitrogen in this way. The method helps to fight not only the wireworm, but also other pest larvae. The digestive system of pests does not have time to adapt to a new type of food. Crop rotation also helps control weeds.
All of these methods are beneficial on large planting areas and are intended either for industrial use or for villages, where the population often has very large plots allocated for potatoes.
Soil liming
The wireworm loves acidic and moist soil, while garden crops for the most part prefer a neutral or alkaline environment. Soil liming is another way to get rid of wireworm without resorting to pesticides or time-consuming agricultural practices, or at least reduce its number.
Liming to control the population of larvae is carried out every 3-4 years. Soil acidity can be determined using litmus paper.
With a large number of nutcracker larvae, it is necessary to water the plants no earlier than the top layer of soil dries to a depth of 15–20 cm. The wireworm does not like dry soil.
Just like with the Colorado potato beetle, there are many folk recipes for how to bring out the wireworm. Some of them are very labor intensive. The other suggests traps.
Poisonous celandine will help keep planted tubers from wireworms. Unfortunately, celandine does not protect new tubers.
Environmentally friendly methods of dealing with wireworms
Almost all methods of protection against wireworms are based on the manufacture of traps for him in one form or another.
Pre-sowing cereals. About a couple of weeks before sowing potatoes, oats or barley are sown in nests of a dozen and a half grains in a future potato field. After the emergence of seedlings, the plants are dug up and wireworms are selected. The method is very labor intensive.
Traps made of rotten organic matter. In this way, they get rid of the wireworm in the middle of spring, when the frosts have already ended, but the ground is still quite cold. Holes are dug in the soil and semi-rotted grass, straw or hay is laid in them. After that, the bookmark is poured with water and covered with boards. The wireworm crawls into organic matter in search of warmth and food. It takes only a couple of days to completely populate the trap with click beetle larvae. After 2 days, the grass is taken out and burned. The procedure is repeated several times.
Professional preparations “Etonem” and “Nemabakt”. They are not available for retail sale, as they are designed for large areas. But perhaps this is the most effective way to protect yourself from click beetle larvae. Preparations are eggs of nematodes, whose main food is wireworm. Able to cope with larvae during one season.
However, Nemabakt is already going on retail, which is logical, since the market for private small farmers is actually even larger than the market for large agricultural producers.
Capturing click beetles with jam. It is applied only in the spring, when there are no cultivated plants yet. Diluted syrup from jam, molasses or just sugar is put outside for the night. In the morning, they destroy trapped insects, 90% of which will probably be pests.
How to arrange traps for clickers and wireworms with crops already planted can be seen in the video.
Traps for click beetles and their larvae
Other ways to expel a wireworm
Onion husks. When planting potatoes, a large armful of onion peel is placed in the hole. When using this method, a calm day is chosen for planting potatoes so that the husk does not scatter over the entire area.
Dry mustard. The wireworm does not like mustard, so when planting root crops in the hole, you can pour dry mustard powder. Use this method when planting potatoes, turnips or radishes.
Repellent plants. Nutcracker larvae do not like phacelia, peas and mustard. They are especially dissatisfied with phacelia, which has the ability to change the acidity of the soil from acidic to neutral. Thus, phacelia is useful not only for expelling the wireworm from the site, but also for the destruction of perennial weeds that love acidic soil. But growing green manure will require additional effort and money.
None of these measures will permanently protect against wireworms, for the reason that click beetles have the ability to fly, which means that at any moment a female click beetle can fly into the site. But it is quite possible to significantly reduce the number of larvae on the site.