If you see a caterpillar fall off a plant and begin to squirm violently – it has just been hit by a tachnid.
Tragically, the caterpillar is doomed, but you have a chance to kill the tachnid fly.
Wait patiently for a few minutes, swat the fly if you see it.
When tachnid larva emerge from a dead caterpillar, they will attempt to burrow into the soil or hide under a pot. Once hidden, they turn into a reddish-brown, hard-shell pupa, and, after about 5 days, they emerge as an adult fly.
Your refuge cage must not contain soil.
Your refuge cage must not provide places for tachnid larva to hide.
Tachnid flies have red eyes, are slightly smaller than a housefly.
Tachnids don’t fly at night.
Get a supply of long-handled fly swatters, and scatter them throughout your sanctuary. Look for tachnids on flat white surfaces, often at the edge of shadow and light. They also seem to be attracted to a sprinkle of water on a white surface.
On a hot day, tachnids will cluster on the north side of a building, often in an alcove or on a door. They are slow when hot.