|Tachinid Fly - Cylindromyia sp.|
Order Diptera / Family Tachinidae
Live adult Tachinid flies photographed in the wild at Ogle County, Illinois.
This fly's larval hosts include stink bugs, noctuid moths and some grasshoppers (Acrididae) . Adult Tachinids feed on nectar and flower pollen. Over 1,300 species have been recorded in North America, and more than 10,000 species worldwide, making tachinids the second largest family of Diptera, after Tipulidae (crane flies).
Tachinids parasitize at least eight orders of insects as hosts; Lepidoptera larvae probably support the largest number of species, esp. in the large subfamilies Tachininae and Goniinae. Flies in subfamily Phasiinae most often parasitize true bugs in Hemiptera such as stink bugs, leaf-footed bugs (below), seed bugs and damsel bugs .
Beetles are not immune to Tachinid depredation. Both adults and larvae of Scarabidae (scarab beetles), Cerambycidae (longhorned beetles), Elateridae (click beetles; larvae are called wireworms), Carabidae (ground beetles), Chrysomelidae (leaf beetles) are all victimized by fly larvae that have developed an impressive array of armaments for penetrating the tough, chitinous exoskeleton of the Coleoptera. Even some weevils are attacked, their larvae are vulnerable while burrowing. Insects in Orthoptera, Mantidae, Dermaptera, as well as Diptera larvae of Tipulidae and Tabanidae all serve as hosts. Hymenoptera alone among the large orders appears to have escaped the tachinids' attention.
Parasites of Lepidoptera caterpillars can be too effective if you're planning a butterfly garden, and silkworm ranchers consider tachinids pests, preying as they do on Bombyx mori caterpillars.  Of the insects that attack silkworm, the most important are the tachinids commonly known as ujiflies (or uziflies). There are at least four species of ujifly that attack silkworms viz., Japanese ujifly, Crossocosmia sericariae (Rondani); Hime ujifly, Ctenophorocera pavida (Meigen); Tasar ujifly, Blepharipa zebina (Walker) and the Indian ujifly, Exorista bombycis .
Tachinids are endoparasites, meaning they develop within their host, but they do not interfere with its growth or development. Such parasites are known as konobionts, as opposed to idiobiont, a parasitoid that halts the growth and development of its host (usually by injecting a paralyzing toxin). 
Flies of North America - Order Diptera. Flies are prevalent in virtually all habitats, with over 16,000 species in North America. Flies can be distinguished from all other insects in that they only have one pair of normal wings. Most flies have compound eyes and mouthparts adapted for piercing, lapping or sucking fluids.
Syrphidae | Flies Index | Tachinidae | Bee Flies | Robber Flies