rice. 1. Common mayfly
(Ephemera vulgata):
A - imago, B - larva.

Order Mayflies (Ephemeroptera)

They have two pairs of mesh wings and three long tail filaments. The first pair of wings is longer than the second. The oral apparatus is underdeveloped. Development with incomplete transformation. Adults live only a few hours and die after reproduction, hence the name of the order. Larvae hatch from eggs laid in water. The larvae live in water for 2-3 years, feeding on plants and plant debris. Insect larvae living in water with incomplete metamorphosis are called naiads. The larvae have tracheal gills on the abdominal segments and a well-developed gnawing type mouthpart (Fig. 1).

Order of Dragonflies (Odonata)

rice. 2. Shiny beauty (Calopteryx
splendens) (A) and swamp dragonfly
(Leucorrhinia pectoralis) (B).

They have two pairs of long transparent wings, permeated with a dense network of veins. The head is movable. On the head there are very large compound eyes, short antennae and a gnawing type mouthparts. Adults hunt flying insects in flight. Development with incomplete transformation. Predatory larvae (naiads) emerge from eggs laid in water. They have a special organ for capturing food - a mask (Fig. 3). The mask is a modified lower lip; when inactive, it covers the lower part of the head; during hunting, it is thrown forward. Dragonfly larvae feed on small animals living in water (mayfly larvae, mosquito larvae, fish fry, etc.). Gas exchange occurs in the tracheal gills, which can be external or internal. The external tracheal gills look like three leaf-shaped appendages at the posterior end of the abdomen (arrows, lutea). The internal gills are the posterior section of the intestine, braided by trachea (rocker arm, pasterns).

rice. 3.
1 - mask.

The order Dragonflies is divided into suborders: Homoptera (Zygoptera), Homoptera (Anisoptera). Homoptera (Fig. 2A) dragonflies include dragonflies with a narrow abdomen, folding their wings upward (beauties, arrows). Among the heteroptera (Fig. 2B) are dragonflies with a thick abdomen; when landing, their wings do not fold (yoke, tailstocks).

Dragonflies are one of the most ancient insects, known from fossil remains from the Carboniferous period of the Paleozoic era. This order includes the extinct paleodictyoptera, which reached a wingspan of 90 cm.

Mayflies Along with dragonflies, they are among the oldest insects, the fossil remains of which are known from the Devonian period. The Greek word "ephemeron", from which the scientific name of the order is derived, means fleeting, quickly passing. Indeed, mayfly adults live from several hours to several days without feeding at all. These are delicate, slender insects with transparent wings that point upward when at rest. Characteristic posture is sitting mayflies with raised front legs and an abdomen, on top of which there are 2 or 3 tail filaments. The intestines are filled with air, which the mayfly swallows, so the abdomen, like a balloon, performs an aerostatic function.

Large compound eyes in males are divided into two lobes - upper and lower. The upper ones can be larger, mushroom-shaped or turban-shaped in shape. The antennae are short and subulate. The oral organs are completely reduced.

In the development of mayflies, a unique process for winged insects is observed - molting in the adult stage. From the larva a winged individual emerges - the subimago, which through the adult moults for a few seconds or minutes. The latter begins to reproduce.

The exit of mayflies often wears mass character, in this case one can observe the swarming of insects, during which the sexes meet. Eggs are laid in the water immediately after mating or after a short time, after which the insects die, covering the banks of reservoirs with their bodies. Nature allows them a day or two, and sometimes only a few hours. Therefore, they do not waste time on food and drink, but devote their entire short lives to procreation. If you light a lantern on the bank of a pond or river on a summer evening at dusk, mayflies will flock to its light. Their simple dance (flapping their wings upward and smoothly soaring downward) is a very serious activity. These are mating games. Males that fertilize females die; females, having laid eggs in the water, also die.

Larvae emerging from eggs live much longer than their parents. They spend a year, two, three in reservoirs, feeding on silt, algae and small aquatic life. The time comes, and the mayfly larva rises to the surface of the water, its old shell cracks, and a winged insect is born. But that is not all. To become an adult - a unique case among winged insects - the mayfly will have to molt one more time. Only then will she become capable of reproduction. And then - the wedding dance, and everything repeats from the beginning.

In the Baikal region, 77 species of mayflies belonging to 11 families have been recorded. In taiga regions, representatives of the families Leptophlebiidae and Ephemerellidae are most often found. These are small mayflies with 2 or 3 tail filaments. Males have larger eyes and often translucent abdominal segments. Subimagos are distinguished by translucent wings.

Mayfly larvae are well known to all fishermen - this is one of the best baits that fish readily bite on. They differ from dragonfly larvae by long tail filaments, and from stonefly larvae, which they are very similar to, in that they have three tail filaments, not two.

Order Mayflies (Ephemeroptera)
The mayfly is easy to recognize. They have two pairs of mesh transparent and very thin wings, and the front ones are always much larger than the hind wings (in some mayflies the hind wings are not developed at all), and at the end of the abdomen there are three or, rarely, two long thin tail filaments. In calm weather in the evening, it is interesting to observe their characteristic flight: quickly flapping their wings, they soar up, and then freeze and, thanks to the large surface of the wings and long tail filaments, descend down, like on a parachute. Then take off again, again a smooth fall. This “dance” is performed by mayflies during the breeding season - the male flies up to the female and immediately in the air from below attaches spermatophores to her genital openings, of which mayflies have two - right and left.

It is no coincidence that these graceful insects are called mayflies or mayflies: some of them actually live one day as adults, sometimes even less - several hours, although some sometimes live for several days, but always not for long.

A short flight, during which mayflies can find themselves in new favorable conditions, and reproduction are the biological functions that are carried out by the adult stage of these insects.

Adult mayflies do not feed; moreover, they cannot take food. Their mouth parts are underdeveloped and soft, and their intestines are turned into an air bubble, which lightens the weight of the insect. This is why mayflies float so easily in the air and descend so smoothly and slowly when their wings stop flapping.

After mating, the males die and the females lay eggs. Among insects it is difficult to find another order within which the eggs would be so diverse in appearance. In some species the eggs are laid in clusters, in others they are scattered; eggs come with anchors that cling to underwater objects. It is rare, but viviparity also occurs, for example, in the two-winged mayfly (CIoeon dipterum), which does not have hind wings.

All mayfly larvae develop in water. Despite the great diversity in the general body shape of mayfly larvae of different species, they can always be distinguished from other aquatic insects by some typical features. The first thing that catches your eye is the long tail threads. Usually there are three of them, less often only two, if only the cerci are developed and the median filament is reduced. The main feature of mayfly larvae is that they have tracheal gills on the first 7 abdominal segments. True, larvae that have just hatched from eggs usually do not yet have gills; for example, in Ephemera larvae they appear only on the fourth day.

Tracheal gills come in very different shapes - in the form of simple or feathery plates, often with fringes, sometimes in the form of a bunch of processes extending from the sides of the segments. The trachea extend into the gills, just as they extend into the bases of the tail filaments. Tail filaments help mayfly larvae to swim, acting on the same principle as a dolphin's tail, i.e., moving in a vertical plane.

Most mayfly larvae live in fast-moving streams and rivers, although some species live in stagnant bodies of water.

Larvae of different species live differently - some crawl among thickets of aquatic plants, others build burrows in sheer steep banks, there are forms that burrow in the mud, and there are those living under stones, attached to their undersides in turbulent streams - these are easy to recognize by wide flattened body.

Mayfly larvae also feed differently. Some of them are predatory, many feed on decaying remains - detritus, silt, etc. The larvae of chiropectes, living at the bottom of fast streams, are interesting in that their jaw palps and front legs are covered with long hairs that filter out passing food particles and act as trapping net.

The life of the larva often lasts 2-3 years, and during this period the larva molts many times. 23 molts have been reliably recorded, but the number is probably much higher. When the larva reaches its final size, it develops into an adult insect. There are many ways to transform.

In larvae - inhabitants of calm waters, towards the end of the larval LIFE, the body weight is lighter due to the fact that many air bubbles are formed between the last skin of the larva and the new skin of the future winged insect. Having become light, the larva floats to the surface. After this, gas bubbles begin to appear in the now empty intestines. (Remember that in adult mayflies, the stomach turns into an air bubble!) The skin of the larva bursts, the adult insect, sitting on it, like on a boat, quickly spreads its wings and flies away. In some cases, a huge amount of skins float up. Thus, on Lake Michigan in North America, it happens that the wind drives to the shore such an abundance of floating skins left after the friendly emergence of the mayfly Ephemera simulans that they cover many hectares of the shoreline with a layer reaching a thickness of several feet.

Mayfly larvae living in fast rivers crawl onto the shore or onto some object sticking out of the water and also very quickly turn into winged insects, which soon take off. But it turns out that the already fledged mayfly has not yet completed its development. The mayfly (subimago) emerging from the last larval skin, after flying for some time, sits on some blade of grass and molts in 2-3 minutes, and sometimes faster. The skin of a winged insect bursts along a longitudinal seam on the back, and a new winged stage emerges from the shed skin, this time already capable of reproduction (imago). In no other order of insects, except mayflies, does fledged individuals molt, and mayflies have two winged forms - immature and mature, separated by molting.

The larvae of the family Prosopistomidae are distinguished by a very wide, leaf-shaped, compressed body; their gills are hidden under the lateral processes of fused segments, so that they form a gill cavity. The tail appendages of these larvae resemble the fork of lower crustaceans (Fig. 177, 4). It is no wonder that they were described at one time by the famous zoologist Geoffroy Saint-Hilaire as crustaceans. These larvae live in fast streams under stones.

In true mayflies (family Ephemeridae), the larvae have an elongated cylindrical body with strong burrowing legs. These larvae dig tunnels in the clayey soil of slow-flowing rivers.

Heptageniidae larvae (family Heptageniidae) have a moderately elongated body, flattened in the dorsoventral direction. Their legs are long, tenacious, their tail filaments are long - these larvae deftly crawl among stones and underwater plants.

The larvae of low-veined mayflies (family Oligoneuridae) are distinguished by their large size and compressed body, and their tail filaments are short, shorter than the length of the body.

Representatives of the baetidae family live mainly in stagnant bodies of water and are characterized by legs pointing to the sides.

Mayflies

order of insects Length 0.2-4 cm. Over 2000 species, widely distributed. Predatory larvae live in water; fish food. Development 1-3 years. Adults live from several hours to several days, some species live for 1 day (hence the name).

Mayflies (Ephemeroptera), an ancient order of insects, including about 1600 species. Distributed everywhere. As a rule, they have two pairs of delicate wings, the front ones being larger than the back ones. Rarely the hind wings are reduced. In adulthood, they do not feed, which is associated with the reduction of oral organs and a short period of life. The antennae are bristle-like. Compound eyes (cm. COMPACTED EYES) large. The abdomen ends in two or three caudal filaments. The intestines are filled with air, which makes flight much easier. The genital openings are paired. Development with incomplete transformation. Naiad-type larvae live in a variety of fresh water bodies; as a rule, they are predators with gnawing mouthparts. On the sides of the abdomen are leaf-shaped tracheal gills. They swim by moving their belly up and down, sometimes rowing with their legs. The larvae develop from several months to two to three years. The emergence of winged insects is widespread. The number of mayflies during this period reaches tens of thousands. The development cycle has two winged stages, separated by molting. The first of them is immature, or subimago. After a short period of summer, the subimago molts into an adult insect. Most adult mayflies live from one and a half hours to two to three days - hence the name. Females of some species live for two to three weeks. They are food items for many commercial fish. Larvae of a number of species are used in monitoring natural ecosystems as indicators of water conditions.

encyclopedic Dictionary. 2009 .

See what “mayflies” are in other dictionaries:

Mayflies Caenis horaria Scientific classification ... Wikipedia

- (Ephemeroptera), order of insects. One of the oldest, known from the Carboniferous. Naib, primitive of winged insects. Dl. 2 40 mm. The fore wings are larger than the hind wings; in some, the hind wings are absent. At the end of the abdomen there are 3 caudal filaments. The oral organs of... ... Biological encyclopedic dictionary

Mayflies, an order of insects with delicate transparent wings and thin, long tail filaments. Length 0.2-4 cm. Over 2000 species, widely distributed. Found near fresh water bodies (aquatic larvae). Massive flights of mayflies are accompanied by... ... Modern encyclopedia

Mayflies- Mayflies Mayflies, an order of insects with delicate transparent wings and thin, long tail filaments. Length 0.2-4 cm. Over 2000 species, widely distributed. Found near fresh water bodies (aquatic larvae). Massive summer mayfly... ... Illustrated Encyclopedic Dictionary

- (Ephemeroptera) order of winged insects. P. have 2 similar, separated by molting, winged subimago and imago phases, during which they do not feed and live for a short time from several seconds to several days, some species for 1 day (hence... ... Great Soviet Encyclopedia

Insect squad. Dl. 0.2 4 cm. Over 2000 species, widely distributed. Predatory larvae live in water; fish food. Development 1 3 years. Adults live from several. hours to several hours days, some types 1 day (hence the name) ... Natural science. encyclopedic Dictionary

True mayflies Ephemera danica On ... Wikipedia

Seven-day mayflies Rhithrogena germanica ... Wikipedia

Two-tailed mayflies ... Wikipedia

Paryveinous mayflies Scientific classification Kingdom: Animals Type: Arthropods Class: Insects ... Wikipedia

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Tender insects with transparent wings - the so-called mayflies - sometimes flock to the light of lanterns lit on river banks on warm, quiet evenings in huge numbers - the so-called mayflies (Fig. 175).

It's easy to recognize them. They have two pairs of mesh transparent and very thin wings, and the front ones are always much larger than the hind wings (in some mayflies the hind wings are not developed at all), and at the end of the abdomen there are three or, rarely, two long thin tail filaments. In calm weather in the evening, it is interesting to observe their characteristic flight: quickly flapping their wings, they soar up, and then freeze and, thanks to the large surface of the wings and long tail filaments, descend down, like on a parachute. Then take off again, again a smooth fall. This “dance” is performed by mayflies during the breeding season - the male flies up to the female and immediately in the air from below attaches spermatophores to her genital openings, of which mayflies have two - right and left.

It is no coincidence that these graceful insects are called mayflies or mayflies: some of them actually live one day as adults, sometimes even less - several hours, although some sometimes live for several days, but always not for long.

A short flight, during which mayflies can find themselves in new favorable conditions, and reproduction are the biological functions that are carried out by the adult stage of these insects.

Adult mayflies do not feed; moreover, they cannot take food. Their mouth parts are underdeveloped and soft, and their intestines are turned into an air bubble, which lightens the weight of the insect. This is why mayflies float so easily in the air and descend so smoothly and slowly when their wings stop flapping.

After mating, the males die and the females lay eggs. Among insects it is difficult to find another order within which eggs would be so diverse in appearance (Fig. 176). In some species the eggs are laid in clusters, in others they are scattered; eggs come with anchors that cling to underwater objects. Rarely, but viviparity also occurs, for example, in a bird without hind wings Diptera mayfly(Cioeon dipterum).

All mayfly larvae develop in water. Despite the great diversity in the general body shape of mayfly larvae of different species, they can always be distinguished from other aquatic insects by some typical features. The first thing that catches your eye is the long tail threads. Usually there are three of them (Fig. 177), less often only two, if only the cerci are developed and the median filament is reduced. The main feature of mayfly larvae is that they have tracheal gills on the first 7 abdominal segments. True, larvae that have just hatched from eggs usually do not yet have gills; for example, in Ephemera larvae they appear only on the fourth day.

Tracheal gills come in very different shapes - in the form of simple or feathery plates, often with fringes, sometimes in the form of a bunch of processes extending from the sides of the segments. The trachea extend into the gills, just as they extend into the bases of the tail filaments. Tail filaments help mayfly larvae to swim, acting on the same principle as a dolphin's tail, i.e., moving in a vertical plane.

Most mayfly larvae live in fast-moving streams and rivers, although some species live in stagnant bodies of water.

Larvae of different species live differently - some crawl among thickets of aquatic plants, others build burrows in sheer steep banks, there are forms that burrow in the mud, and there are those living under stones, attached to their undersides in turbulent streams - these are easy to recognize by wide flattened body.

Mayfly larvae also feed differently. Some of them are predatory, many feed on decaying remains - detritus, silt, etc. The larvae of chiropectes, living at the bottom of fast streams, are interesting in that their jaw palps and front legs are covered with long hairs that filter out passing food particles and act as trapping net.

The life of the larva often lasts 2-3 years, and during this period the larva molts many times. 23 molts have been reliably recorded, but the number is probably much higher. When the larva reaches its final size, it develops into an adult insect. There are many ways to transform.

In larvae - inhabitants of calm waters, towards the end of the larval LIFE, the body weight is lighter due to the fact that many air bubbles are formed between the last skin of the larva and the new skin of the future winged insect. Having become light, the larva floats to the surface. After this, gas bubbles begin to appear in the now empty intestines. (Remember that in adult mayflies, the stomach turns into an air bubble!) The skin of the larva bursts, the adult insect, sitting on it, like on a boat, quickly spreads its wings and flies away. In some cases, a huge amount of skins float up. Thus, on Lake Michigan in North America, it happens that the wind drives to the shore such an abundance of floating skins left after the friendly emergence of the mayfly Ephemera simulans that they cover many hectares of the shoreline with a layer reaching a thickness of several feet.

Mayfly larvae living in fast rivers crawl onto the shore or onto some object sticking out of the water and also very quickly turn into winged insects, which soon take off. But it turns out that the already fledged mayfly has not yet completed its development. The mayfly (subimago) emerging from the last larval skin, after flying for some time, sits on some blade of grass and molts in 2-3 minutes, and sometimes faster (Fig. 178). The skin of a winged insect bursts along a longitudinal seam on the back, and a new winged stage emerges from the shed skin, this time already capable of reproduction (imago). In no other order of insects, except for mayflies, does fledged individuals molt, and mayflies have two winged forms - immature and mature, separated by molting (Fig. 179).

Larvae family prosopist(Prosopistomidae) are distinguished by a very wide leaf-shaped compressed body, their gills are hidden under the lateral processes of fused segments, so that they form a gill cavity. The tail appendages of these larvae resemble the fork of lower crustaceans (Fig. 177, 4). It is no wonder that they were described at one time by the famous zoologist Geoffroy Saint-Hilaire as crustaceans. These larvae live in fast streams under stones.

U real mayflies(family Ephemeridae) larvae have an elongated cylindrical body with strong burrowing legs. These larvae dig tunnels in the clayey soil of slow-flowing rivers.

Larvae heptageny(family Heptageniidae) have a moderately elongated body, flattened in the dorso-ventral direction. Their legs are long, tenacious, their tail filaments are long - these larvae deftly crawl among stones and underwater plants.

Larvae low-veined mayflies(family Oligoneuridae) are distinguished by their large size and compressed body, and their tail filaments are short, shorter than the length of the body.

Representatives baetid family(Baetidae) live mainly in stagnant bodies of water and are characterized by legs pointing to the sides.

Mayfly larvae are sensitive to the presence of various foreign chemical compounds in water, and their number in those rivers into which wastewater from factories flows is sharply reduced.

If we compare the degree of diversity of adult mayflies and their larvae, it turns out that adult mayflies of different species are much less different from each other than the larvae. This is understandable if we remember that adult mayflies do not live so long and lead approximately the same lifestyle. And the larvae sometimes develop for more than a year, in different reservoirs, in different places of reservoirs that differ in soil, flow, etc., and they, naturally, have developed different adaptations.

It is interesting that along the banks of lowland rivers there are a huge number of adult mayflies, they fly in whole clouds, and their larvae, burrowing into the muddy bottom, are quite difficult to find. On the contrary, in mountain streams it happens that mayfly larvae swarm under stones, and adults are quite difficult to find - they hide in the coastal grass and lead a hidden lifestyle.

The number of mayfly species is small - just over 1,500 species are known.

Mayflies are distributed throughout the globe, with the exception of some oceanic islands. For example, they are not found on the Hawaiian Islands in the Pacific Ocean or on the island of St. Helena in the Atlantic.

The paleontological history of mayflies goes back to the Carboniferous period of the Paleozoic era. By the nature of development, by the structure of the tail appendages, by molting in adulthood and by many other characteristics, mayflies can be considered more or less close to bristletails. Mayflies are a very ancient group; if we rely on the peculiarities of the location of the wing veins, on the inability of the wings to fold, it is possible, as our outstanding specialist in fossil insects did

A.V. Martynov, consider mayflies as “ancient-winged” insects. Probably, the direct ancestors of today's mayflies were winged insects, which in the larval stage, like bristletails, lived in damp places on land - under stones, in rock cracks, etc. - and only gradually began to develop in water.

Fish readily feed on mayfly larvae; in our northern rivers (Onega, Pechora), mayflies represent the main type of food for many commercial fish.

Animal life: in 6 volumes. - M.: Enlightenment. Edited by professors N.A. Gladkov, A.V. Mikheev. 1970 .