Tahini, tahini flies, tahini insects. Beneficial insects are our helpers Flies: “flies bite harder before rain”
Flies are very annoying and people are trying to destroy and not let them into the home. But fly to fly is different. This fly does not live near a person, and we will not see it on dining table she prefers to live near flowering plants, on flowering milkweed.
The tahina fly at first glance is similar to a house fly, but why does it live far from a person and at home? Yes, because tahini flies, one might say, are beneficial insects, they destroy harmful insects.
Tahini flies were called hedgehogs for the bristles that cover the body of this insect, there are quite a lot of them and they are very strong. When a fly sits on a flower, they bristle, making it look like a hedgehog, so they called takhin urchins.
Interesting tahini fly insect. How do flies kill pests? There are several types of tahini. So flies of the tahini isomer help to destroy the grain , dangerous pest wheat, they lay thousands of ripe eggs on spring wheat, and the caterpillars of the gray armyworm swallow them along with the plant they feed on.
The egg of a black fly enters the intestines of the caterpillar, the digestive juices contribute to the dissolution of the egg. In this case, the shell is destroyed, and the tahina larva is inside the caterpillar. All summer the larva grows in the caterpillar, and when the caterpillar has already turned into a chrysalis, the barnacle larva will eat the host and come out.
A small yellow-white tahina larva will degenerate into a brown-red barrel of puparia, and after some time an adult tahina fly will degenerate from it. But she still bears little resemblance to a fly. She has a large forehead bubble on her head, which helped her get out of the puparium. The wings hang down helplessly, they are not yet shaped. The bubble will eventually disappear, leaving a small mark on the head, and the wings will get stronger. The tahini isomer fly is ready to fly.
The tahini fly arrived early in the clearing with flowers and cereals, there are no caterpillars of the grain scoop yet. Therefore, she will lay eggs for alfalfa scoops and scoops of the mamester genus. The tahini isomer reproduces twice in a year. The first time her eggs fall and are brought up in the caterpillars of the alfalfa cutworm, and the second time in the caterpillars of the grain scoop.
Tahini maigenia flies lay their eggs directly on the body of the host - the rapeseed sawfly, which loves to spoil the mustard crops. The hedgehog lays oblong eggs directly on the sawfly caterpillars and there they will go through all stages of development.
All those who believe that flies are useless creatures are greatly mistaken. Tahini flies are very useful, especially for horticultural and horticultural crops. Their larvae are natural enemies of many insects that cause significant damage. agriculture.
They were called hedgehogs for the many hard bristles that cover the entire body. In general, their appearance differs little from appearance common flies. In total, the family of tachin flies includes more than 8200 species. Depending on the species, their body length varies from 3 millimeters to 2 centimeters. The abdomen consists of 4 rings.
Photo by Stephen Cresswell These flies love sunny but not hot weather. At this time, tahini can most often be seen on plant flowers, where they feed on pollen and nectar. But not all species are most active during daylight hours.
According to the method of infecting other insects with their larvae, all acorns can be divided into 3 groups:
- The former lay their eggs on the leaves of plants, where caterpillars of sawflies, caterpillars of butterflies and other insect pests crawl nearby. Their eggs are so small that caterpillars, eating a leaf, may not even notice them.
- The latter specialize in soil insects and lay their eggs in the ground, where the larvae that hatch after a while begin to independently search for their future food base (adult insects or their larvae).
- Still others lay their eggs directly IN or ON the body of the insect.
Photo by Leslie Butler Very rarely, but there are also viviparous species of these flies. Most often, in one caterpillar victim, larvae of only one type of fly are found, and even then, a little - no more than 2-3 individuals.
Photo by JYoung Thus, by regulating the number of insect pests, tahini bring great benefit. They are especially good for dealing with Colorado potato beetle, gypsy moths, May beetles, bedbugs, butterflies and other pests.
There are at least 8000 species in the world fauna, 700 in Russia. Tachins play an important role in biogeocenoses as regulators of the abundance of many species of insects, including economically dangerous ones (in particular, lepidoptera from very many families, hymenoptera , Coleoptera, Hemiptera, Cockroaches, Earwigs, Praying Mantises, Some Diptera, Embiyi and Orthoptera) (Fig. 84-86).
Females of some tahini species lay their eggs on the integument of the host, while females of other species inject eggs into the host's body. Among the tachinids there is a group of flies that lay small eggs on the host's food plant. Special place are occupied by ovoviviparous tahini, which lay their larvae in the host's habitat. Tachin larvae undergo development in the host organism before pupation.
Rice. 84. Diptera from the family Tachinidae: A - Tachina grossa, B - Ernestia rudis, C - tahina Istochaeta lays eggs on mating beetles Popillia japonica, D - eggs of Winthemia cruentata on a hawk caterpillar, E - eggs of Ectophasia crassipennis on a harmful turtle (G - Gaponov , 1997, 2003; D - Viktorov, 1967).
There are two large groups tachin according to the method of infection of the host. The first group includes tahini, which lay their eggs on the host. The fecundity of females of these species is relatively low (100-200 eggs). Within this group, there are two subgroups:
1.1. Eggs at the time of laying do not contain a developed embryo. The development of eggs is completed already on the host, the larvae independently bore into the host (oviparous type of development);
1.2. The egg completes its development in the female genital tract, resulting in
place of egg production. Phylogenetically, this subgroup is related to the first. In female species of this subgroup, the vagina, into which the unpaired oviduct flows, turns into a "uterus" containing fertilized and developing eggs. At the time of laying, the egg contains an already developed and ready-to-hatch larva.
 |
Rice. 85. Tachinidae larvae: posterior spiracles of LS: A - Zaira cinerea (III) (Prota, 1963), B - Ernestia rudis (Prell, 1915), C - Blepharipa pratensis (Gaponov and Khitsova, 1995); general form: D - Ernestia rudis (I, planidium on plant) (Prell, 1915), E - Dexia vacua (I, planidium) (Dupuis, 1963); oropharyngeal apparatus: E - Drino lota (III), F, H - Blepharipa pratensis (F - II, H - III).
The second group includes tachins that lay their eggs outside the host, but near it or on its host plant. Infection of the host is carried out by actively moving larvae of the first instar or by eggs swallowed by it with food. Within the second group, two subgroups are also distinguished:
2.1. Ovolarviparous (ovoviviparous) species with a planidian-type larva. From a thin-walled egg, immediately after its laying, a larva of the first instar emerges, lying in wait or actively looking for the host (Fig. 85);
2.2. Microoviparous species with small (microtypic) eggs attached to fodder plant owner. First instar larvae hatch from an egg swallowed by the host along with food.
Adult flies feed on nectar and pollen, being quite valuable to pollinators. Tahines are used in biological methods plant protection, as they are important regulators of the number of insect hosts.
 |
Rice. 86. Wings of Rhinophoridae (A) and Tachinidae (B-D): A - Rhinophora lepida, B - Gymnosoma rotundatum, C - Alophorapusilla, D - Athrycia impressa, E - Elomyia lateralis (Bei-Bienko, 1970)
It's a pretty big fly. with a bright yellow belly, transparent wings and a black spot on the back. A completely harmless insect, which in “peacetime” carelessly and rather calmly searches flower beds, beds with flowering straight plants, collecting nectar, which it feeds on. Although tahini love the sun, and it seems that they even purr with pleasure, sitting on a flower, but still in extreme heat they prefer to hide somewhere in the shade of plants, under awnings, flying out of shelters only in the afternoon hours.
And where does the poise of tahina go when the time comes to “be born”! She no longer pays attention to flower nectar, practically does not feed, but is frantically looking for a “maternity hospital”, since she will lay the eggs that have ripened in her only to a certain owner. Among the tahini, there are few that develop at the expense of only one of some kind of host: basically, flies attach children to many types of hosts, more or less related.
How does the “birth” of tahina happen? Mu-ha begins to lay eggs as soon as it smells the owner, regardless of whether you need to lay eggs directly into his body or spread them on the victim's path. There are also tragic embarrassments when a viviparous tahina (there are such among many species) does not have time to find a host and lay live larvae in it. And "The time has already come for the larvae to feed, and ... they begin to eat their own mother, destroying internal organs her abdomen. The same tahini that lay off regular eggs, having found the owner, they manage to attach themselves to him so that he does not even have time to twitch.
This is what happens with the Colorado potato beetle: having saddled the beetle for a second, the tahina leaves two tiny white lumps at the beginning of the back, not far from the head. As they say, neither to get it with a paw, to clean it off, nor to knock it down with a flap of wings. In the warmth and anticipation of a large amount of food, the eggs quickly turn into larvae, which, in turn, rush to screw into the body of the beetle - the pantry nutrients. The inlet also serves as a ventilation hole - for breathing. Cunning larvae know that it is impossible to immediately eat the vital organs of the host: after all, his premature death will destroy them too. And only on last step of its development, the larva, having already eaten everything that is possible, releases a huge amount of digestive juice, leaving no hope of survival for the host: all of its innards will be digested and will be eaten by a voracious larva, which should already be left -give an empty beetle shell and rush to pupate in the soil.
Those types of tahini that lay in the soil or on plants also rarely miss: their eggs will definitely fall on the path of the desired insect. If the eggs are laid in the soil, then they are intended for soil insects, and the larvae that emerge from them in the majority still find their owner, wandering a little underground labyrinths.
But, for example, tahina sturmia, which knows only one owner in its life - gypsy moth, acts with his offspring more carefully. Since spring, the female sturmia lays microscopic eggs (5000!) in heaps on young leaves of trees.
Tahina is sure: gypsy moth caterpillars will definitely swallow them! And if the eggs are swallowed, then larvae will come out of them, which will begin to eat caterpillar tissues. Since there is plenty of food, the larvae are not particularly in a hurry to develop, they grow so slowly that the caterpillar will already have time to turn into a chrysalis, not suspecting that it will never be destined to become a butterfly anyway.
Above, I already mentioned that there are also viviparous tahini. One of them - architas - specially flies to those plants that feed on the owner she needs, and it is precisely along his paths that she lays out larvae (and not eggs). And so that the newborns do not fall to the ground, tahina securely attaches them to the leaves with the help of tiny caps at the rear end of the larvae. Such a baby sits for itself and waits for the appearance of the owner-victim, and then, like a cobra from a vase, as if by the sound of an invisible flute, it rises and attacks, burrowing into the body of a caterpillar.
There are tahini, destroying the bugs-turtles we hate - this is a golden phasia. There are those who rid the gardens of the beetles. In general, among the Diptera, perhaps, we cannot find a more useful fly: it reliably pollinates plants and destroys pests. Ta-khin are specially imported, propagated, if necessary, for example, to clear the forest from the invasion of pests.
And the gardener will be very lucky if tahina flies settle in his garden. And for this, you don’t need to put a lot of effort, it’s enough to grow fragrant herbs on the site, especially with a sweet smell - honey plants.
Many, many years ago, when I was just starting entomology as a boy, I saw a magnificent caterpillar, thick and bright, burrowing into the ground. "Yeah, - Think, - it is she who buries herself in order to turn into a chrysalis". I pulled it out, put it in a box, and at home - in a jar of earth: let it pupate here, and then some huge, unknown to me butterfly will come out of the chrysalis, probably also very beautiful, and then I will put it in my collection.
Imagine my disappointment when, a few months later, in a jar tied with gauze, instead of a butterfly, a good dozen hefty hairy flies buzzed! I poured out the earth from the jar - the skin of the chrysalis was empty. So, the future butterfly was eaten by fly larvae - wow, how angry I was with them then! So my first acquaintance with flies-tachins took place.
But it is precisely this that is useful to humans for a huge (about 5 thousand species) family of tachin flies, that they exterminate a myriad of pests of agricultural crops. These flies are, as it were, natural "regulators" of the population of a wide variety of insects, vigilant and tireless, which under natural conditions will never allow any kind of insect to breed excessively, suddenly finding very favorable conditions for reproduction. It is only difficult for them to work in places that have been greatly altered by man, and even in those cases when a foreign pest, new to these places, has appeared in the fields, brought here in some way and multiplied. But scientists brought to the affected fields those types of tahini that lived in the homeland of a foreign pest and fed on it there. The settlers quickly settled in and got down to business, the harvest was saved. Other methods of breeding these useful flies in special "tachinaria" are also being developed.
Outwardly, tachins are similar to house, meat or carrion flies, but in general they are more stocky and covered with elastic bristles. Russian name- hedgehogs - they got it precisely because of these bristles, resembling hedgehog needles under a magnifying glass. The color of tahini is different - gray, black, brown; they also have different sizes: from small flies to huge two-centimeter flies, “flies-sokotuh”, echinomy (by the way, exterminating caterpillars of harmful forest silkworms).
In spring, tahini are the first flying insects to appear in our reserve near Isilkul. The forest is still completely bare, the local primroses have not yet appeared - the yellow suns of adonis and the light cream bells of sleep-grass, there is still snow in places and only open glades dry up, how, having missed flying living creatures over the winter, you instantly and with pleasure notice the first movement in on withered last year's grasses - the flight of a tahina fly, looking for its prey. A fly flies attentively, bending around dry blades of grass, clods of earth, from time to time sits down, rises again and flies between blades of grass - and so on for hours. You get tired of watching and you leave, but the Tsokotukha has much more patience: she will explore the clearing for many days, perhaps all spring, until she finds what she needs.
Some species of aquatic flies lay their eggs directly on plants, in the habitats of the caterpillars they need, and the tachini larvae that emerge from the eggs find them themselves. Other species stick their eggs directly onto the integument of the "host". More than once I had to find caterpillars with a bunch of tahini eggs tightly glued to it - it was not possible to separate them with either a needle or a scalpel, without risking breaking through the caterpillar's skin. Many species of aerflies stick their eggs in the air - on a flying "host". An interesting pursuit of tahin for taking off fillies was described by Professor P.I. Marikovsky in his book Insect Friends. And I managed to photograph even such a scene in the micro-reserve near Novosibirsk; a ktyr sits on the finger of my left hand, biting some kind of fly he caught (he used the finger I deliberately put out as a landing site), and next to him, on the same finger, two small tahinkas guard him, chasing him everywhere, and with the obvious intention of putting off eggs on it - most likely, also on the fly. Drawing from this curious and rare photo- on this page.
As you can see, tachins do not always pursue and infect harmful insects, among their victims there are also useful ones, such as, for example, the same hunter-ktyr. But still, entomologists classify the vast majority of hedgehogs as very useful species. Especially great is the importance of tahini in the extermination of unpaired Siberian and pine silkworms, meadow moth, winter cutworm, a bread bug-turtle and many other pests of agriculture and forestry.
For the reproduction of tahini, it is very important to keep unmowed part of the meadows with wild nectarifers, on which adult flies feed, especially umbrella flies - carrots, angelica, angelica, hemlock, cow parsnip. In such untouched corners you sometimes see an amazing picture: a magnificently lace umbrella of a carrot, and on it a good dozen (or even two or three dozen) urchins sit - small, medium and large. In the center, as the “hostess of the feast”, a huge echinomia - a black giantess with a red belly, gray prickly knephilia and ernestia, small thieves sat around, and round-bellied phasia - a thunderstorm of plant bugs - hold wings not like a fly, widely spaced to the side perpendicular to the body . By the way, these same flies from the genus phasia attach their eggs only to flying bugs, and not just anywhere, but under the underside of the elytra, from where the bug is not able to scrape off its deadly load, which it receives quite unexpectedly, during a lightning air attack of phasia .
A motley company of tahini feeds on a fragrant umbrella, slowly sucks nectar, and eggs ripen in fly bellies. And then, when these eggs have already been laid, the children of takhin will come out of them - larvae, burrow into the body of a forest bug, butterfly caterpillars, sawfly or beetle larvae and begin to eat it from the inside, leaving the vital organs "for a snack". From the hostess, who recently still bravely crawled through the plants, only the skin will remain. Mature tahini larvae will crawl out of it, burrow into the ground and turn into pupae there.
By the way, many flies, including tahin, sirphs, even house flies pupae are not quite common. That is, a chrysalis is like a chrysalis - a pale, motionless and soft likeness of a fly, but it is placed in a very strong leathery oval bag. And the “secret” is that the larva does not weave this cocoon, but swells up, gets fatter and does something with its skin that it separates from the body and becomes dry and hard, not at all like a larva. Inside this hardened shell, further transformations of the insect take place. Entomologists call such fly cases puparia (navel is a chrysalis in Latin). And puparia lie in the ground - brown durable barrels - all autumn and winter.
And next spring and summer, new armadas of young barnacles, having fed on meadow flowers, carefully comb forests, fields, meadows, and each of them will certainly find its victim - the future food for the fly's offspring.
