Family: Tachinidae (Tachinid Fly)
Who: Tachinid flies are a family of parasitoids (parasites that kill their host). Though they sound a little scary, they’re actually great to have around! There are over 8,000 species with quite varied appearances; you can identify tachinids by their bristly, stout bodies.
What: Tachinid flies are often used as biological controls due to their unique life cycles. The eggs are usually laid directly on the host, where the larvae then burrow after they hatch. The immatures, known as the less-than-great-sounding term “maggots,” then feed on the living tissues, eventually killing whatever host they’re living inside. Once grown, they pupate and the adults emerge feeding generally on flower nectar. That said, due to the size of the family, there is a lot of variance in life cycles; some are actually just parasitic and don’t kill their hosts.
When: Depending on the location, these can be active year-round.
Where: Worldwide, except Antarctica.
Why: Like other insects, these flies are attracted to areas with large amounts of resources, such as shelter and food. Nectar for the adults is important, and obviously, if there’s a large amount of hosts, this will attract tachinids as well.
How: Keeping nectar flowers present year-round attracts not only tachinid flies but also other helpful biological controls as well as pollinators. Some species are also available commercially, but proceed with caution: Most tachinids are not host-specific, and unless you’re releasing them in a greenhouse setting, they’ll likely just fly off, which is less than helpful.
Lauren’s Notes: Though hairy and bristly, many of these flies can be absolutely gorgeous in color! They range from metallic green and blue to even red!