Tachinidae
The Tachinidae are a large and variable family of true flies within the insect order Diptera, with more than 8,200 known species and many more to be discovered. Over 1300 species have been described in North America alone. Insects in this family commonly are called tachina flies or simply tachinids. As far as is known, they all are Protelean parasitoids, or occasionally parasites, of Arthropoda.
Occurrence
The family is cosmopolitan. Species occur in many habitats in many regions, including Neotropical, Nearctic,Afrotropical,Palaearctic, Oriental, Australasian and Oceanic.
Life cycle
Reproductive strategies vary greatly between Tachinid species, largely, but not always clearly, according to their respective life cycles. This means that they tend to be generalists rather than specialists. Comparatively few are restricted to a single host species, so there is little tendency towards the close co-evolution one finds in the adaptations of many specialist species to their hosts, such as are typical of protelean parasitoids among the Hymenoptera.