Runners (lat.Trichoptera) - a detachment of insects with complete transformation, with exclusively aquatic larvae. The order Trichoptera includes 13,574 species, united in 45 families and about 600 genera, widespread on all continents except Antarctica, and on many oceanic islands. It is assumed that the world fauna may contain up to 50 thousand species of caddis flies.
Adult insects resemble small dimly colored moths, but their body and especially the front wings are covered with hairs. In some species, females descend under water to lay eggs. They are usually found in the vicinity of water bodies where their larval stages live. The transformation is complete. Larvae and pupae in the overwhelming majority of species live in water or live in the depths of the bottom of water bodies, in rare cases, they constantly live outside the water or live off the coast in seawater.
Caddisflies are easily recognizable for a number of features. The oral apparatus of adults is reduced, while the mandibles (upper jaws) are not functional or rudimentary, but maxillary (mandibular) and labial (labial) palps can be seen. In addition, adult insects have a well-developed proboscis used by some species to absorb fluids.
Antennae filiform, usually comparable in length to the forewings, sometimes noticeably shorter or much longer.
The wings are membranous, developed on the meso- and metathorax. The front ones are longer than the back ones. Like the body, they are covered with hairs, sometimes parts of the wings can be covered with bristles. A marginal fringe of hairs or hair-like scales is developed along the edges of the wings; the size of this fringe in small species may be more than 2 times the width of the hind wing.
Caddis larval stages are aquatic, found in lakes, rivers and streams around the world and are essential components of food webs in these freshwater ecosystems. Adult caddisflies, unlike the larvae, are terrestrial, almost do not feed, their life span is limited to one or two weeks. Many of these insects have a characteristic unpleasant odor caused by secretions from specific glands. This smell can act as a repellent for enemies of caddis flies, such as birds.
After fertilization, the female caddisfly lays eggs glued together with a mucous mass, attaching them to pitfalls or plants. The hatching of the larvae from the eggs occurs after three weeks. Like most fully metamorphosed insect larvae, they have well-developed mandibles and well-developed pectoral legs, but abdominal limbs are usually absent (except for a pair on the last abdominal segment, each leg may carry a strong "anal claw"). The transformation of the larva into an adult insect occurs through the pupal stage.
Almost all Trichoptera larvae build a cap or house. The simplest form of caps is a reed tube. A more complex structure is a tubular case of individual pieces of leaves, which the larva gnaws and arranges along a spiral line. Depending on the type of caddis flies, the building material may vary. Sometimes the building material is arranged in tiles, and they are either pieces of reed, or pieces of leaves and fragments of bark.
To build their caps, caddisflies use moss, blades of grass, pieces of dead wood, fresh tree twigs, needles, horsetail stems mixed with other plant residues; they attach both small shells and sunflower husks to their dwellings. Sometimes buildings may not be from plant debris, but from small shells, for example, peas, small coils, young meadows and other mollusks. In case of danger, the larvae climb into their house and plug the entrance to it with their head covered with armor made of chitin.
Less common are larvae that do not have caps - the so-called campode larvae. Such larvae are mainly predators, building special trapping nets from thin spider webs. These funnel-shaped nets are located with a wide opening against the current and attach motionlessly to aquatic plants, rocks and other underwater objects.
The larva pupates under water in a cap built by it. The pupa has wing buds, very long antennae, large eyes and huge mandibles, with the help of which it destroys the cap of the cap. Thin filamentous gills are visible on the abdomen. The pupa can be equipped with long swimming legs. At the posterior end of the pupa's body there are long bristles, with the help of which it clears the hole in the sieve cap, which is easily clogged with silt, and thus provides fresh water access. The opening of the anterior sieve cap is cleaned with the help of bristles sitting on the upper lip, and possibly also with the help of elongated jaws. For the emergence of the imago, the pupa floats to the surface, acting as oars with rowing middle legs. Adult insects fly out in about a month.
The bottom of many clean freshwater reservoirs is covered with insects that resemble nocturnal ones. They belong to a special order of insects and are called caddisflies.
Adult caddis flies bear a striking resemblance to the night moth. Scientists have long been interested in these strange creatures. They described more than a thousand of their species, which were divided into dozens of families and erase genera, and spread over the entire earth's surface, with the exception of the cold climatic conditions of Antarctica and some oceanic islands.
Features and habitat of caddis flies
In all its external features, an adult caddisfly resembles a moth with a dull gray and brown color. There are small hairs on the front wings of this insect, it is thanks to them that the caddisfly differs from.
Butterflies have scales on their wings instead of hairs. On the photo caddis and also in real life is absolutely not attractive. Its wings in a calm state are folded in a roof-like manner on the back.
A rather large head with eyes and a rather long mustache, similar to threads, stands out well against this background. Special attention should be paid to the eyes of this creature. He has more of them than the usual norm for all - 2 faceted eyes on the sides of the head and 2-3 auxiliary ones, which are located at the top or in front of the head.
Instead of a mouth at caddis insect a proboscis with a tongue was formed. The whole head is covered with warts, which makes it not a very pleasant sight. Their legs are slender and not very strong.
They can be seen everywhere and everywhere. Its name fly caddis flies got it because he prefers to live in shallow and clean bodies of water. They are comfortable in streams, ponds, lakes, and in some cases in swamps, but not too polluted. A clean environment is very important to detachment of caddisflies.
Mating process of caddis flies
Caddis larvae very similar to mayflies and the fact that during their development they are also forced to live in the water. In order to make it convenient for them to live there, they themselves build houses, which are practically one piece with their body.
This cocoon is firmly attached to the insect larva. They have to move around with this house on themselves. Anyone who has tried to retrieve the larva from its hideout knows that this is a difficult task.
And while maintaining its integrity is generally impossible. But there is a secret how to lure him out of there. It is enough just to fit it from behind with something sharp and thin. In order to build a house for the larva, a variety of building materials are used, even broken glass.
An unusual experiment was carried out. They took a caddisfly larva, placed it in a clean reservoir, where, except for the larva, clean water and broken glass, there was nothing. The larva had no choice but to build itself a house of glass.
In the photo, the caddis larva in a cocoon
Learned an original, creative and comfortable home. Such a transparent house made it possible to observe how water constantly passes through the gill of the larva. Gills in the form of white threads are located on the back and side of this interesting creature. Whatever the dwelling of the larva of this insect is, it always has the shape of a tube.
There is a variety of dwellings in the form of a horn or a spiral. Caddis larvae slowly move along the bottom of the reservoir together with their house, sticking their head out of it so that they can see everything around.
And at the slightest danger, the head hides in the house and the movement stops. The house itself is made of materials that simply merge with the bottom and become completely invisible. For every living being, oxygen is simply necessary. How does the caddis larva solve this problem? Everything is very simple and at the same time tricky.
They build their houses from plants, in which the process of photosynthesis is constantly taking place, and thus, merging in work with their house, provide themselves with the oxygen necessary for their life.
Mormyshka caddis flies is the lightest and most common bait among many fishermen. It is versatile and easy to mine. Good catching caddis flies falls on the time from mid-May to mid-June.
It is then that the larvae are the largest. After this time, the larvae turn into pupae, and later into "butterflies", which are called caddis fly... In winter, it is a little more difficult to get the caddisfly from the bottom of the reservoir.
It is necessary to drill a hole and lower a broom of birch twigs into it, onto which all the caddis larvae will slide. They are stored for a long time in an ordinary jar with clean water.
The nature and lifestyle of caddis flies
Adult caddis flies live in reeds and grass on the banks of water bodies. In the evenings, they create massive flocks and fly out to mate. These flights are rather big and take them a long distance from their place of permanent residence. The distance can be a kilometer or more.
Adults, at the slightest danger, emit an unpleasant fetid odor, which they try to scare away and protect themselves from possible danger. You can even hear this smell if you just pick them up.
Types of caddis flies
On the earthly planet, there is simply a huge number of different types of caddis flies. They differ in their appearance, habitat, character and even nutrition.
For example, not all caddis flies are as harmless as they seem. There are those who, in search of food, can envelop a large body of water with their silk trail, into which not only small insects but also other inhabitants of the underwater world come across.
Each species has its own favorite place of residence. Some people like quiet clean backwaters, others prefer the bottom of a fast flowing mountain river. Accordingly, their size and color are completely different.
Caddis feeding
Most of all, caddisflies eat the green pulp of aquatic plants. Those predatory caddis flies who, in order to get their food, use the help of their web, love various small insects, and. These caddisflies have a very well-developed jaw, which helps them cope with prey.
Reproduction and life expectancy of caddis flies
The life of an adult insect is not long. It lasts one to two weeks. The life cycle of the caddis flies is divided into four stages. Its development begins with an egg, which turns into a laurel. It passes into the navel and at the extremities into a mature caddis flies.
Fertilized females lay their eggs in different ways, depending on their species and habitat. Most often, eggs are laid on the surface of aquatic plants, which originate at the bottom of water bodies.
Over time, thanks to dew and raindrops, they gradually sink to the very bottom, and after 21 days, caddis larvae are formed from these eggs. The sticky gel protects the eggs from all environmental factors. They gradually swell and turn into laurels, which outwardly resemble thin and elongated worms.
Gradually, laurels grow and turn into pupae. Adult caddis flies emerge from pupae after 30 days. Caddisflies are useful not only because they serve as an excellent bait for fishing. Most freshwater fish feed on these beneficial insects.
Less common are larvae that do not have caps - the so-called campode larvae. Such larvae are mainly predators, building special trapping nets from thin spider webs. These funnel-shaped nets are located with a wide opening against the current and attach motionlessly to aquatic plants, rocks and other underwater objects.
Chrysalis
The larva pupates under water in a cap built by it. The pupa has wing buds, very long antennae, large eyes and huge mandibles, with the help of which it destroys the cap of the cap. Thin filamentous gills are visible on the abdomen. The pupa can be equipped with long swimming legs. At the posterior end of the pupa's body there are long bristles, with the help of which it clears the hole in the sieve cap, which is easily clogged with silt, and thus provides fresh water access. The opening of the anterior sieve cap is cleaned with the help of bristles sitting on the upper lip, and possibly also with the help of elongated jaws. For the emergence of the imago, the pupa floats to the surface, acting as oars with rowing middle legs. Adult insects fly out in about a month.
Classification
Based on the diversity of larvae, two groups of families are distinguished Trichoptera... Group Annulipalpia includes those families of caddis flies, the larvae of which build nets (serve for catching prey and shelter). Larvae families Rhyacophillidae and Hydrobiosidae I do not form larval caps, but the pupa is located inside a domed structure of mineral fragments. Hydroptilidae- the larvae are free-living until the last stage, after which they build a cap, which can be free or attached to the substrate. Pupation takes place inside it. In the larvae of the family Glossosomatidae, the cap is similar to the caps of other Annulipalpia, however, the larva stretches a transverse thread under the dome, which allows the larva to drag the house. With each new stage, the larva builds a new cap, and then a new cap is built for pupation. In this case, the thread is removed and the cap is attached to the substrate. Family group Intgripalpia mostly tubular covers are built. The material for the building and the type of construction are species-specific. The larva is mobile and completes the building with each larval stage.
- Suborder Annulipalpia
- Hydropsychoidea: Arctopsychidae- Dipseudopsidae - Ecnomidae- † Electralbertidae - Hyalopsychidae - Hydropsychidae - Polycentropodidae - Psychomyiidae- Xiphocentronidae
- † Necrotaulioidea: Necrotauliidae
- Philopotamoidea: Philopotamidae - Stenopsychidae
- Rhyacophiloidea: Glossosomatidae - Hydrobiosidae - Hydroptilidae- † Prorhyacophilidae - Rhyacophilidae
- Suborder Integripalpia
- Leptoceroidea: Atriplectididae - Calamoceratidae- Kokiriidae - Leptoceridae- Limnocentropodidae - Molannidae - Odontoceridae- Philorheithridae
- Limnephiloidea: Apataniidae - Brachycentridae - Goeridae - Lepidostomatidae - Limnephilidae- Oeconesidae - Pisuliidae - Rossianidae - † Taymyrelectronidae - Uenoidae
- Phryganeoidea: † Baissoferidae - † Dysoneuridae - † Kalophryganeidae - Phryganeidae - Phryganopsychidae- Plectrotarsidae
- Sericostomatoidea: Anomalopsychidae- Antipodoeciidae - Barbarochthonidae - Beraeidae - Calocidae - Chathamiidae - Conoesucidae - Helicophidae - Helicopsychidae- Hydrosalpingidae - Petrothrincidae - Sericostomatidae- Incertae Sedis
- Tasimioidea: Tasimiidae
- † Vitimotaulioidea: Vitimotauliidae
- Incertae Sedis Genera: † Conchindusia - † Folindusia - † Indusia - † Molindusia - † Ostracindusia - † Pelindusia - † Piscindusia - † Quinquania - † Scyphindusia - † Secrindusia - † Terrindusia
Notes (edit)
Literature
- Holzenthal R. W., Blahnik, R. J., Prather, A. L., and Kjer K. M. Order Trichoptera Kirby 1813 (Insecta), Caddisflies // Linneaus Tercentenary: Progress in Invertebrate Taxonomy. Zootaxa./ Zhang, Z.-Q., and Shear, W.A. (Eds) .. - 2007. - T. 1668. - S. 639-698 (1-766).
- Kjer, K. M .; Blahnik, R. J .; Holzenthal, R. W. 2002: Phylogeny of Caddisflies (Insecta, Trichoptera). // Zoologica scripta, 31: 83–91.
- Schmid, F. 1998: Genera of the Trichoptera of Canada and Adjoining or Adjacent United States. - National Research Council of Canada, Ottawa.
- Ward, J. B. 1999: An annotated checklist of the caddis (Trichoptera) of the New Zealand subregion. // Records of the Canterbury Museum, 13: 75–95.
- A. V. Martynov. Caddis flies (vol. 1). - Leningrad, publishing house of the Academy of Sciences, 1934.
, herbaceous plants (flowers) of reservoirs and marshes, aquatic invertebrates, freshwater and anadromous fish, amphibians and reptiles
4
pocket field determinant, including: inhabitants of reservoirs
65
methodical benefits, among which 10 textbooks are devoted to aquatic ecology and hydrobiology, and 40
educational methodological films on methodologies carrying out research work in nature (in the field).
Caddis flies and their larvae
Caddis flies (Trichoptera) are a special order of insects. In the USSR, there are currently more than 600 species of them, making up 16 families.
Adult insects resemble moths in appearance. They are most often painted in different shades of brown or gray and generally have a rather nondescript appearance. They fly a little, often sit on coastal plants. They usually keep near water bodies, but sometimes they fly away quite far from them. When at rest, fold the wings along the back at an acute angle, like a house roof. They have the ability to run quite dexterously on the surface of the water. They feed like butterflies, flower sap. Many adults do not take any food.
Adult caddis flies Glyphotaelius punctatolmeatus). Is eating. led.
Many of these insects have a characteristic, rather unpleasant odor, depending on the secretion of the skin glands, which is especially noticeable if the adult specimen is held in the fingers of the hand. It is possible that this smell plays the role of a deterrent against the enemies of caddis flies, for example, birds.
Less common are larvae that do not have caps - most of the so-called campode larvae, which differ in many features of their structure from the previous ones.
Covers of various caddisflies. (According to A.F. Wintergalter.)
1 - agripnia (Agrypnia pagetana); 2 - caddis flies (Phryganea grandis); 3 - Grammotaulius nitidus); 4, 5 - Glyphotaelius pellucidus; 6 - Platypteryx brevipennis; 7 - Limnophilus stigma; 8-18 - Limnophilus rhombicus and L. flavicornis; 19 - anabolism (Anabolia nervosa); 20 - Stenophylax stellatus; 21 - Stenophylax rotundipennis; 22 - quiver (Limnophilus vitattus); 23 - molanna (Molanna angustata); 24 - goera (Goera pilosa). Is eating. led.
Caddis larvae lead an aquatic lifestyle. They are found everywhere in large numbers - in rivers, ponds, lakes, streams, not excluding even the smallest bodies of water, such as persistent ditches and puddles. These larvae are very interesting in their various biological characteristics and at the same time are easily observed in natural conditions at the bottom of reservoirs, are easily caught with a net, and live well in aquariums. Because of this, caddisflies are among the most important excursion objects both for a quick acquaintance with them on excursions, and for long-term systematic observation of them in a laboratory setting.
Most of the larvae live in special cases - covers, which they build from a wide variety of materials. Both in form and in material, the covers are very diverse and by themselves can already serve as an object of excursion acquaintance.
The simplest form of caps is a reed tube into which the larva crawls using a ready-made room (agrypnia - Agrypnia pagetana Curt., 1).
A more complex structure is a tubular case of individual pieces of leaves, which the larva gnaws and places along a spiral line (caddis flies - Phryganea grandis L; 2). Sometimes the building material is arranged in a tiled manner, and they are either pieces of reed (3, Grammotaulius), or pieces of leaves and fragments of bark (4, 5, Glyphotalius). Less often, plant remains are superimposed across the cap (Limnophilus stigma Curt., 7).
How diverse the building material of the caps is, is shown by the buildings of the most common caddisflies in our country - the rhombic caddis flies (Limnophilus rhombicus L.) and the caddis flies (Limnophilus flavicornis F.). They use for building both moss (8), and various blades of grass (9), and pieces of dead wood (10), and fresh tree twigs (11), and needles (12), and horsetail stems mixed with other plant residues (13 ); they attach small shells to their dwelling (13), and sunflower husks (14), etc. Sometimes representatives of these species build their tubes not from plant remains, but from small shells, for example, peas (15), small coils , young meadows and other molluscs (16, 17, 18).
From this it is clear that it is possible to identify the larvae by the building material only to a certain extent. The architectural form of the cap is of great importance, which is very typical in some genera (Phryganea, Molanna), but even it gives only an approximate idea of what species the observer is dealing with.
Species of caddisflies living in fast-flowing waters build caps from large and small grains of sand (Stenophylax, 20 and 21). Sometimes these mosaic structures have the form of a wide flat shield, on the surface of which water glides freely, without turning the cap over and without tearing it from its place (Molanna - Molanna, 23). The anabolic larva (Anabolia, 19) attaches heavy twigs and sticks to the sandy tube, which in fast-flowing water most likely play the role of a kind of anchor. The goer larva (24) attaches 2-3 pebbles to the flattened sandy tube.
Two types of caddis larvae. There is. 1 - caddis flies (Phryganea grand), the gills of the larva are depicted in an elevated state - in a living larva they are pressed to the body; 2 - larva that does not build caps, campode-shaped (Holocentropus diiblus).
It is clear that the boot is perfect protective device for larvae. He gives them a safe, lasting refuge. In addition, this shelter, built from environmental materials, is well camouflaged among other underwater objects. It is remarkable that some forms of the covers copy underwater objects, as it were. Thus, the cap of the caddis flies Limnophilus stigma strikingly resembles an alder fruit that has fallen into the water. Such protection is all the more necessary for caddis flies because their larvae serve as tasty food for many predators and, in particular, are eagerly eaten by fish. This has long been known to anglers who use these larvae for hooks.
At first glance, the boot looks like a bulky, uncomfortable structure. However, upon closer inspection, it turns out that this is not the case. It should not be overlooked that the cap, according to Archimedes' law, weighs very little under water, and in those cases when the building material approaches the specific gravity of water, the cap is, as it were, weightless. Thanks to reliable spider web fastenings, the walls of the boot are very strong, which is easy to be convinced of by anyone who tries to tear it apart. The heterogeneous material from which the walls of the covers are made is fitted together with wonderful art. All this makes us put caddis larvae among the first-class builders in the insect world. The construction is based on very strong silkworms, with the help of which the caddisflies connect and connect a variety of building materials. These cobweb threads are spun by the larvae from the secretions of a pair of long spider glands, which open with a common duct on the lower lip and are built in exactly the same way as in caterpillars. The inside of the tube is completely covered with a delicate cobweb lining.
As you grow the larva builds on the front edge of its cap, making it wider; the rear end, which has already become narrow, gradually breaks off or is nibbled by the larva.
If you take out the larva from the cap (in the aquarium), then it looks extremely helpless, tries to hide under various objects, and after a while begins to build itself a new cap. Not finding the usual material, the larva also uses building particles new to it. So, for example, it is possible to force the larvae removed from the covers, which were made from plant debris, to build new dwellings from scraps of colored paper, sawdust, eggshells, even staniol, etc. successfully offer small beads, crushed glass, crushed bricks, metal filings.
Let us now trace the movements of the larva, choosing for this some large species, for example, the large caddisflies often found in our country - large or striped (P. grandis and P. striata).
The larva captured by the net during fishing hides in its cap and lies completely motionless, so that when parsing the contents of the net, it is easy to view it, mixing it with the stems of aquatic plants. Let's put the caught larva into a flat vessel (a plate of water). Here she will soon expose the front end of her body from the cap and begin to crawl along the bottom of the vessel, dragging her dwelling behind her. At the same time, you can see that the head, the first segment of the chest, covered with a hard shell, and three pairs of long legs protrude from the cap. If you substitute some stems or sticks for the larva, you can be sure how tenacious its limbs are: it can crawl in various positions on both the upper and lower sides of underwater objects.
Caddis larvae taken out of the caps. Is eating. led. 1 - Phryganea; 2 - Odontocerum alblcorne; 3 - Helicopsyche sperata.
Let's try to extract the larva from its hideout. It is easy to see that it offers great resistance at the same time: if you drag it out of the tube, taking it by the front end of the body, then it is easier to break it than to release it from the cap. Meanwhile, the cap seems rather spacious in comparison with the size of the larva's body, and at first glance the force with which it is retained in its tube is incomprehensible.
To show what the matter is, let's try to expel the larva from the cap in another way: introduce a thin stick or straw through the back opening of the cap and disturb the larva from the posterior end of the abdomen. This technique makes her crawl out.
When examining, first of all, one should pay attention to the difference in the density of the cover, which covers the protected (cap) and unprotected part of the larva's body. Under the cover of the cap is the abdomen, consisting of ten segments, and the posterior (third) segment of the chest. These parts are covered with soft skin. On the contrary, the first two segments of the breast, which, when crawling, the larva exposes from the cap, are strongly chitinized and have a much darker color. The significance of this phenomenon is quite understandable, especially if we recall the similar distinction between protected and unprotected body parts in other animals, the famous example of which is the famous hermit crab.
Instruments are instructive, with the help of which the larva firmly lingers in its shelter when trying to extract it by the head end. At the posterior end of the abdomen, it has a pair of appendages, which are equipped with strong sharp hooks, the tips of which are directed in opposite directions. With the help of these hooks, the larva catches on the inner walls of the cap, acting like a pair of hooks. In addition, the third segment of the breast, which is adjacent to the outer edge of the cap, has three verrucous projections. The latter can protrude strongly and, in turn, resting on the walls of the cap, prevent the larva from falling out of its shelter.
The campode-shaped larvae, which do not build caps, have a completely different body shape than those described above. Their body is laterally compressed and does not have a pair of hooks at the posterior end.
Breath... Already a cursory examination of the naked larva reveals that its round, oblong caterpillar-like body is covered with whitish filamentous outgrowths. This is nothing more than the gills of the larva, which is under the protection of the cap. The branchial apparatus requires a constant change of water. This is achieved by the fact that the larva sitting in the cap makes peculiar movements with the abdomen, thanks to which a constant flow of water through the cap is established. Hence, the meaning of the second hole at the rear end of the cap, through which water is pushed out during breathing, is also understandable. The wriggling of the abdomen can also be observed on the naked larva, if it is placed in a vessel with water. Similar movements are produced by larvae of the campode type, which do not build a cap.
Feed on the larvae of caddisflies, mainly plant substances, for example, leaves of aquatic plants.
The larvae belonging to the families of friganeids and limnophyllids are herbivorous forms: They are quite voracious and can eat per day an amount of food equal to the weight of their own body or even slightly more (in young larvae). The larvae of the molannid family are predators that feed on daphnia, chironomid larvae, etc. (Kolenkina, 1951). However, cases were observed that the larvae of the great caddisfly attacked water donkeys, frog tadpoles and even each other. In aquariums, caddis larvae can be successfully fed with lettuce leaves.
Campode-shaped larvae for the most part lead a predatory lifestyle and build special trapping nets for catching prey, woven from thin spider webs. These funnel-shaped nets are located with a wide opening against the current and attach motionlessly to aquatic plants, rocks and other underwater objects. This is a kind of device for catching mayfly larvae, small crustaceans and similar live prey.
Reproduction and development. Along with crawling larvae, on excursions you can often find caps, which are sealed at both ends with sieve caps (Fig. On the right). These are pupated caddisflies, which braid the holes of their caps with a cobweb, leaving a free passage for water, but protecting themselves from predators. Usually pupation occurs in larvae in the spring, in our latitudes in May (caddis flies) or in June (larvae with sandy caps). Adult insects fly out in about a month.
If on the excursion it was possible to find such a sealed cap, then it can be opened in order to examine the chrysalis enclosed inside, if it has already formed. The pupa is completely unlike the larva and has a very peculiar appearance (Fig. 240). It possesses wing buds, very long antennae, large eyes and huge mandibles, with the help of which it, leaving its shelter with further development, destroys the cap of the cap. Thin filamentous gills are visible on the abdomen.
Pupa of caddis flies Limnophilus. Is eating. led.
The pupa has long swimming legs. At the posterior end of the pupa's body there are long bristles, with the help of which it clears the hole in the sieve cap, which is easily clogged with silt, and thus provides fresh water access. The opening of the anterior sieve cap is cleaned with the help of bristles sitting on the upper lip, and possibly also with the help of elongated jaws.
Using this apparatus, the pupa makes rhythmic pendulum-like movements inside the cap. The matured pupa leaves its shelter, gnawing through the cap. It is remarkable that it floats freely on the surface of the water for several minutes after being released from the cap. Here she sheds her skin and turns into an adult caddisfly, which soon rises into the air.
It should be noted that the interesting phenomenon of short-term swimming of the pupa, as well as the process of hatching of an adult insect, is rarely observed on excursions. This phenomenon requires close, aquarium observation. But relatively often it is necessary to catch dead, completely mature pupae without a cap from the water with a net. This is explained by the fact that the pupa that emerged from the cap quickly dies if it does not find a way out of the water. In addition, pupal skins floating on the surface of the water are often found. 
Eggs of various caddis flies: spiral, ring-shaped and finger-shaped (Triaenodes, Phryganea, Glyphotaelius). Is eating. led.
Caddisflies(Fig. 99A) - these are inconspicuous, non-tangy, brown or brown insects, 2-24 mm long, found near reservoirs where their larvae develop, hence their name. The detachment includes over 15,000 species of caddis flies.
Lifestyle
Adult insects are inactive during the day, they sit hiding in the coastal grass or bushes, and even when scared take off reluctantly. Sitting caddisflies are easy to recognize: their long filamentous antennae are connected together and extended forward, and their wings are folded on the back like a roof. The mouth organs of the caddis flies are underdeveloped, so they do not feed at all, they are limited to licking moisture. They do not live long, usually about a week.
They begin to fly at dusk, before sunset, often over the very surface of the water, sometimes they even glide on the water. Small caddisflies sometimes swarm above the coastal bushes.
Life cycle
Larva
Caddis larvae inhabit various reservoirs with both standing and running water.
House (cover). They are easily recognizable by the house covers they make themselves. Larvae of different species build different houses, gluing together with the secret of spinning glands grains of sand, small pebbles, fragments of shells, pieces of plants. The houses also differ in the shape and arrangement of the component parts. It is easier to distinguish the types of caddisflies by the caps-houses than by the features of the structure of the body. As it grows, the larva builds on the front cover-house.
Motion. To move, the larva sticks out its head and chest with three pairs of tenacious legs from the house and awkwardly crawls along the bottom, dragging the boot behind it. So she looks for food and building material for the superstructure of the house. Material from the site
Nutrition. Herbivorous larvae predominate, scraping the soft tissues of aquatic plants, but there are also omnivorous and carnivorous larvae.
Role (meaning). Larvae of caddis flies, in turn, constitute an important part of the food of various fish and some