This family is part of the superfamily Calyptratae, or Calyptrate Muscoid Flies, which include common house flies, bot flies, blow files, flesh flies, etc. the family Tachinidae is the second largest of the order Diptera, with about 1,350 known North American species. Some ways of distinguishing Tachinids from other similar flies is that their aristae (the hair extension from the third segment of the antennae) is not hairy, they have a large lobe under their last dorsal thoracic segment, and have bristles in two small regions under the wing joint. Tachinid flies are fairly common, and come in a variety of colors.
In general, Tachinids are large, bristly flies and tend to be parasitoids, specifically larvae of other insects such as those in Lepidoptera and Coleoptera. They parasitize the host either by laying an egg directly on the host, after which the egg hatches and the larvae enters and feeds on the host, or they lay eggs on plant and the egg is ingested by the host or the egg hatches and attaches to a host on its own. The host is nearly always killed, thus Tachinids are parasitoids, not parasites (which usually leave the host alive). The parasitoid can affect the host's behavior as well, causing it to feed on differently or extending its pupal life span to allow the parasitoid to grow and feed for longer. Many Tachinids can appear wasplike or beelike as well, the following are two examples.