Tachinidae

Tachinid

The Tachinidae ( Tachinidae ), a parasite also flies are a diverse family of Diptera with about 8000 species worldwide, which is represented by about 500 species in Central Europe.

System

The Tachinidae are considered sister group of Rhinophoridae, together with these as a sister group of the botfly. They belong to the Calyptratae, the extended family of houseflies and blowflies.

The systematics within the Tachinidae is still largely unclear and controversial. Usually four subfamilies are distinguished:

• Phasiinae: This group is represented in Central Europe with about 60 species. Physically they are quite different, some species are slender with an elongated abdomen, others have a spherical or a flattened, brightly colored abdomen. Relatively uniform contrast, they are in their biology, there are mainly parasitized bugs and the eggs are still immature when filing. To this group belongs the bright colored bugs fly.
• Dexiinae: In Central Europe, there are about 75 species of this subfamily, which parasitize on beetles, butterflies and sawflies. The larvae of this group are laying eggs already schlüpfreif.
• Tachininae: A large and relatively heterogeneous group with a wide range of host species. In this group you can find the flying hedgehog, which include particularly large and common species. The eggs of all species included schlüpfreife larvae.
• Exoristinae: The most species-rich subfamily includes many very different groups. It can be found among some groups take the immature eggs, but most larvae hatch shortly after oviposition.

Physique

In the Build Tachinidae at least superficially resemble the houseflies and blowflies. A secure distinguishing feature of these and other closely related groups is the Postscutellum, that under the tag ( scutellum ), which forms the posterior margin of the thorax top, bead emerges. In the remaining groups the thorax back is bulged out more or less from the scutellum flat.

Way of life

All species evolve into parasitic larvae, pupae or imagines insects, occasionally also in other arthropods. Among the host animals are found primarily caterpillars of butterflies and after caterpillars of sawflies. But are parasitized beetle, namely except the larvae of scarab beetles and mainly longhorn beetles, the dolls and the imagos larger species, such as beetles or June bugs. Other host species are found among the bugs, grasshoppers, cockroaches and earwigs, sporadically Hymenoptera and Diptera. Excludes aquatic species and insects that do not come in question is too small.

Most tachinid specialize in a few host species or even a single species, but some have a very wide host range. Some species are restricted to host species that live by a certain fodder plant.

The eggs of Tachinidae are either stored directly on the surface of the host or in its vicinity, the females do not have an ovipositor to pierce the host animal. The larvae hatch after a short time, sometimes immediately after oviposition.

The adult flies are most active during the day and feed mainly on nectar and honeydew. Often they are found on flowers with easily accessible nectar sources, only a few species have a proboscis which is sufficient to reach the nectar from flowers with long tube.

Fossil evidence

Fossil Tachinidae are rare. The earliest evidence dates from eozänem Baltic amber. In addition, findings from the slightly younger Dominican amber as well as from various quaternary deposits are known.

Economic Importance

In agriculture, Tachinidae are of great importance in biological pest control. Particularly insects, which caused significant damage to other continents by outbreaks after deportation could be brought by subsequent introduction of the respective parasitic tachinid permanently under control. Examples of this are the little winter moth and the gypsy moth.