Fly Parasites - A Good Thing in a Small Package


Flies are a nuisance to humans and to livestock during the summer months, but they don’t have to be if you employ the help of a small, but mighty beneficial insect… the fly parasite. Tricia shows you how she puts these out in her chicken coop and by the neighbor's horse in our video Beneficial Insects: Parasites.

Life Cycle of the Fly

Female flies are able to lay between 100 and 150 eggs at a time. The eggs develop into the larval (or maggots) stage within 24 hours. The larvae seek out warm dark conditions like a compost pile or manure pile, to develop into the pupa. The fly pupa looks like a reddish brown grain of rice. The pupal stage can normally last from 3 to 6 days after which the adult fly will emerge. So in about a week you have an explosion of flies! Fly parasite cycle

Introduction of the Fly Parasite

Just how do these mighty creatures work? Well the adult fly parasites (look like tiny wasps) seek out the fly pupa and the female will make a hole in the pupal case and lay her eggs inside the fly pupa. In turn the fly parasite eggs feed on the developing fly, therefore, killing the fly before it hatches. The fly parasites will hatch out of the fly pupa in about 17 to 21 days, ready to seek out more pupa.

When to Start Releasing the Fly Parasites

You want to start releasing as soon as the weather warms up. Flies reproduce faster than the fly parasites so it is important to release them on a regular basis (every one to four weeks), especially if you have livestock. What you will actually receive are fly pupae that have been parasitized and the fly parasites are ready to emerge and start doing their job.

Add a Fly Trap for More Control

You can add fly trap for additional control of the adult flies. The traps use a stinky bait to lure in the adult flies into the trap in which they cannot escape. Here are some of the traps available at
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Steve, I believe that the fly parasites only target fly larvae and not butterflies.


Does the fly parasite attack butterfly pupae?


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