The Early Tachinid Fly is a robust fly with a spiny abdomen and a distinctive thin, irregular yellow line across its black abdomen. Adult tachinid flies prefer sucking up sweet nectar from flowers, but larvae prefer protein. Of the 1,300 species of tachinid flies in North America, larvae are almost exclusively internal parasitoids of other insects, especially caterpillars.They feed inside the host, avoiding vital organs until the last stage of their own development (usually killing their host). For this species, females lay one or two eggs on the underside of a certain owlet moth caterpillar (one of the pinion moths, genus Lithophane). The Early Tachinid Fly ranges from British Columbia east to Nova Scotia and south to California and is active in open habitats with flowers, such as meadows and fields.
Photo by Jenny Tollefson on 5/10/20 in Missoula, MT