Houdini Fly (Non-native, Introduced) - Cleptoparasite
NOTE: This is an excerpt from a Crown Bees article. You can read the entire article here.
Characteristics: Large, red eyes (Nicknamed "Devil Fly"; About the size of a fruit fly; dull brown with horizontal stripes on abdomen; when in rest its wings cross over each other; slow, hovering flight style.
The Houdini fly, named after its unique method of escaping from bee nests, parasitizes mason bees. Female Houdini flies lay their eggs in nest cells before the female mason bee can seal the nest. The fly larvae quickly hatch and consume the pollen loaf before the mason bee larvae, which causes them to starve. Once development is complete, the adult Houdini fly inflates its head to break through the mud walls to escape.
Check out the Houdini Fly video on our YouTube channel.
What You Can Do (
1. Only use nesting materials that allow you to open, inspect, and harvest cocoons.
2. Harvest mason bee cocoons - Open nesting materials in the fall and kill Houdini fly larvae. Larvae look like sticky white clusters inside the brood cell, often surrounded by curly orange/brown frass (poop).
3. Control adult mason bee emergence - If you cannot open nesting materials, place your nesting materials in a BeeGuard Bag or another fine mesh bag and close tightly. As the bees emerge, release the mason bees daily and kill any adult Houdini flies.
4. Instantly kill any adult Houdini flies you see hovering around your nesting materials. Some bee raisers have noticed that regularly using a low to medium powered vacuum around nesting materials to suck up Houdini flies has significantly reduced their numbers.
5. Before purchasing mason bees, ask the provider how they harvested and whether they inspected the cocoon for Houdini flies. YES, Crown Bees does inspect ALL cocoons!
Remember: During harvesting, look for a mass of about 10 -20 while or pale yellow maggots with sticky curly frass (poop). Remove and kill all Houdini fly maggots you find during harvesting.
If you have bamboo tubes or drilled blocks of wood that you are unable to open, place the unopened nesting materials in a BeeGuard Bag. As the bees emerge in the spring, release the mason bees daily and kill any adult Houdini flies.
