An adult Tachinid Fly looks ugly, but it's the young fly larva that is most grotesque. It feasts on a caterpillar's insides, saving the most important organs for the last meal.
Tachinid Fly larvae are efficient pest controllers for certain moth species. This particular species parasitizes some tiger moth and also some skipper species. Because of this particular diet in their larval stage, some species of Tachinid Flies have been deliberately imported from other areas to control destructive moth populations here in North America.
A female Tachinid Fly will lay one or two fertilized eggs on, or near, a moth caterpillar. The caterpillar may even inadvertently eat the eggs as it chews through a leaf that the eggs were laid on. The larvae may also latch on to a passing caterpillar and promptly eat a hole into its body. A larva will slowly feeds on the caterpillar's internal parts. Once the fly larva is mostly developed, it will consume the caterpillar's most necessary organs and the caterpillar dies. The fly larva will exit its dead host and move to the ground where it will dig a hole to pupate in. Flying adults emerge from the ground. The spiky, hairy adults drink nectar.
This particular species of Tachinid Fly can be found on flowers, in fields, parks or gardens during the summer and autumn.
Scientific Name: Juriniopsis adusta
Fly or Mosquito
Size (Adult; Length): 9mm to 15mm (0.35in to 0.59in)
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