For those who are accustomed to considering wood lice as insects, it may seem surprising that in reality these creatures are representatives of the order of isopods, in fact, they are small crustaceans. Their closest biological relatives are large giant isopods, as well as a large number of interesting marine crustaceans called sea cockroaches.
But the common crayfish familiar to us, although it can be a stretch to attribute to relatives of wood lice, but quite distant - systematically wood lice and crayfish do not have a very high degree of kinship.
On a note
Thus, to say that a wood lice is an insect is completely wrong, and is a gross mistake. Woodlice have as much in common with insects as humans have with turtles. And, accordingly, calling wood lice bugs or bugs is also a common mistake of the townsfolk.
In the photo below - common woodlice (Armadillidium vulgare) at their summer cottage:
Woodlice are crustaceans that lead a rather secretive lifestyle and are rarely seen by humans. For this reason, attention is paid to them mainly by biologists, as well as gardeners, to whom these creatures can damage the crop. Nevertheless, there are a lot of interesting things both in biology and in the anatomy of wood lice - we will talk about these entertaining nuances further ...
Appearance and photos of wood lice
Almost all types of woodlice have a characteristic appearance of a small "armadillo" with a large number of legs.
Photos of wood lice:
And here is a photo of an armadillo:
The body of the woodlice is covered with hard and hard chitinous shields that protect it from numerous predators. It is these scutes that create the characteristic appearance of the wood lice and noticeably distinguish it from most insects. So, for example, beetles or hemipterans have two dense wings, but never 9-10 separate segments, like woodlice.
The photograph below clearly shows the division of the body of the wood lice into separate segments:
Woodlice have 7 pairs of walking legs, which distinguishes them from the same crayfish with five pairs of walking legs and three pairs of legs that have turned into tools for eating. Insects have only 3 pairs of legs.
The internal structure of woodlice is similar to that of ordinary crayfish. Its respiratory organs resemble gills, but work in lung mode and are located at the base of the five pairs of pectoral legs.
All wood lice have antennae of several segments, along the length and fracture of which individual types of wood lice sometimes differ. In the photo below, these antennae are clearly visible in one of the species:
As a rule, woodlice are painted completely inconspicuously - this allows them to disguise themselves on the ground, in grass and under stones. The two most widespread species of woodlice in our country have a gray body color, others can be lighter and with green tints in color. Only in some species there are patterns or stripes on the body.
There are no special outgrowths and, especially hair, on the body of wood lice.
Review
“For two days my son told us on the phone how scared he was with his grandmother and how he was afraid to go into the summer shower, because there was a shaggy woodlice sitting on the wall.When we arrived to pick him up, we went into the shower especially for the sake of interest. Flycatchers are sitting under the ceiling - such nimble centipedes that eat flies. We explained everything to him in detail, but probably he just wanted us to come as soon as possible.”
Taisiya, Yaroslavl
Here is another photo showing the common armadillo, the most common in the European part of Russia:
The usual body length of woodlice is 0.5-1.5 cm, and the largest species barely grow to 3-4 cm in length. Sometimes they are confused with wood lice due to the similar appearance of larger centipedes from the glomeris family:
However, although bipair centipedes are similar in appearance to woodlice, they are very different in lifestyle and biology.
Types of woodlice: from domestic to oceanic
Today, scientists count more than 5,000 species of wood lice around the world, of which representatives of only a few dozen species are found in our country. Moreover, wood lice are rather heat-loving creatures, and therefore most of their species live in the tropics and subtropical zones.
Despite the similarity of the appearance of different wood lice, even an unprepared person can easily distinguish between the most common varieties of them without much difficulty.
For example, the photo below shows an ordinary armadillo, rather clumsy and slow. When threatened, she has a habit of curling up into a ball. Some individuals have yellowish spots on their backs:
Common wood lice are most often found in vegetable gardens, wastelands and basements.
And then in the photo - woodlice are rough, more mobile and flat than the previous view. It is she who is known as the wood lice, as it often penetrates from the basement into the house:
At the same time, like domestic insects, wood lice in the room try to hide in the most secluded places, choosing the wettest corners, and catch the eye only by chance.
And in the photo below is a sea woodlouse that lives in the shallow waters of the Mediterranean Sea. This is one of the few species that has returned to its original habitat:
In addition, there are species of woodlice that are well adapted to life in a very dry climate. For example, Hemilepistus reaumuri - lives in the deserts of Asia Minor and North Africa, digging holes up to a meter deep to protect from the sun and heat.
In the photo - the desert woodlice goes into a mink:
Giant marine isopods, sometimes growing up to 75 cm in length, are not, strictly speaking, wood lice and are popularly called so only because of the similarity of their appearance with the appearance of real wood lice.
It is interesting
There is also a whole set of species of insects and centipedes, which are often called wood lice by the people, but which do not belong to them, and others do not look like them at all. For example:
- Silverfish, not at all similar to wood lice, but which, nevertheless, are called that way quite often;
- Kivsyaki are long, worm-like centipedes that curl up in a spiral when frightened. They are confused with wood lice due to the fact that they are also found in damp places;
- Glomeris, like two drops of water, are similar to ordinary wood lice, but they are not.
There are no poisonous species among wood lice, and poison cannot be obtained from wood lice, although this contradicts some medieval treatises. Nevertheless, the taste of wood lice is rather disgusting - brave lovers of eating crayfish and shrimp stated that this crustacean strongly gives off urea.
It is interesting
At the same time, giant isopods (“giant woodlice”) taste very good, but due to the complexity of their production, it is extremely difficult to taste such a dish.
Further in the pictures are wood lice, which can be found in almost any garden:
Woodlice sometimes look very original, although the anatomical features characteristic of the entire detachment retain all species.
It is interesting
The so-called lingual woodlouse is not a woodlouse, a parasitic crustacean that attaches to the base of the tongue of some fish species. It feeds on the blood of the host and the mucus secreted by the fish.
Lifestyle and interesting features of the biology of wood lice
Woodlice are the only crustaceans that have completely switched to a terrestrial way of life.
Only a few species returned to the aquatic environment again, but at the same time they retained adaptations to the terrestrial way of life. An example of this are the varieties of wood lice found in the sea (see photo):
However, woodlice and on land are quite strongly attached to moisture. They prefer to settle in the shade, in moist soil, at the roots of trees, under stones and in cellars and basements - anywhere where moisture and coolness remain.
The optimal conditions for the existence of most species of wood lice are humidity of about 95% and a temperature of about 25 ° C.
It is interesting
The most heat-resistant species of woodlice from the genus Hemilepistus, even in the deserts of Central Asia and Africa, dig minks in the sand and live at such a depth where the temperature does not rise above 26 ° C and does not fall below 10 ° C, and the humidity is kept at 95-100%. They emerge from their burrows mainly at night and roam the desert at 15-17°C that are comfortable for them.
Home woodlice are often heralds of problems with the sewerage or water supply, or a clear sign that the house has a damp basement or attic with a leaking roof. As a rule, these animals make their way into apartments and houses from basements and damp attics.
Woodlice are nocturnal creatures, and during daylight hours they can be found active only early in the morning or late in the evening. Basically, during the day they hide under stones, logs and fallen grass, and at night they get out of shelters in search of food.
Woodlice feed on various plant debris: fruits, roots, rotting leaves, grass, falling flowers. In apartments and houses, mold fungi, leaves of house plants in flower pots, and even just slime with bacteria and dust in bathrooms can quite suit them.
It is interesting
Woodlice are extremely dependent on sources of moisture with which they moisten their gills. With a lack of moisture, the crustacean can die from suffocation, since this disrupts the normal functioning of the respiratory system.
Many wood lice hibernate under adverse environmental conditions. Such, for example, are all wood lice living on the territory of Russia, as well as desert species that are in a state of suspended animation in winter.
How do woodlice reproduce?
Woodlice breed regardless of the season, but females only develop eggs when the animal is not hibernating and eating well. Interestingly, the sexual intercourse itself in woodlice lasts a very long time - the female's seminal receptacle opens only a few hours after molting, and the male finds her very early and waits in the appropriate position until the old covers of his chosen one are thrown off.
After fertilization, the eggs enter a special brood pouch located on the female's abdomen in the region of the last pairs of legs. Here they are abundantly supplied with water from special glands and ventilated due to the fact that the front edge of the bag is not closed.
The larvae of woodlice emerge from the eggs, which are called "semolina" in biology. The larva of the woodlice differs from the adult only in the size and underdevelopment of the last pair of legs. A few days later, the field of exit from the bag of semolina molts and turns into a young wood lice.
The photo below shows woodlice larvae that have just emerged from the eggs:
On average (for different species), the development of an egg in the brood pouch lasts 30-35 days, and the larvae after hatching become sexually mature after about 100 days.
It is interesting
All woodlice have developed care of adults for young ones. For example, the reproduction of desert woodlice occurs in their burrows, and in case of danger, an adult crustacean crawls to the exit and curls up into a ball, blocking the entrance to the hole with its shields. In addition, parents lead their brood to sources of food and water until a certain age.
The total life expectancy of wood lice varies from six months to several years. Species that go into suspended animation live longer than their tropical counterparts.
Woodlice in the apartment and in the garden - pests, invaders or random guests?
In most biocenoses, wood lice are very important participants in soil formation processes. They process plant residues that are difficult to digest, and their excrement is a valuable fertilizer.In deserts and steppes, wood lice minks contribute to soil ventilation and better moistening.
The woodlice themselves, under suitable conditions, reproduce in large quantities and serve as food for many species of insects, birds and reptiles.
Typical pests of woodlice are only in greenhouses and gardens, where they can damage the roots of cultivated plants, leaves on bushes and young seedlings. In cellars and cellars, wood lice sometimes feed on potatoes and carrots stored here, but in most cases the losses from them are microscopic, and they cause serious damage only during very mass reproduction.
On a note
Woodlice do not infect the garden and are not brought into it - they live here all the time. Only under normal conditions they are not noticeable here, and with strong moistening of the site and breaks in digging, they can multiply in large quantities.
For the most part, woodlice are those inconspicuous, but very useful creatures that swarm under the forest or field litter of grass and leaves and are engaged in utilizing plant components unused by other members of the natural community. And if you ever see them, then remember that of all the crustaceans, only they had the courage to conquer the land environment. And this is a great achievement!
Interesting video: armadillo (macro)
Entertaining biology of wood lice ...
