Community science is opening a new chapter in the fight against the European Houdini fly, a pest that arrived in the Pacific Northwest about a decade ago, has no predators, and has been quietly raiding Mason bee nests ever since. We’re seeing it spread to eastern US states as well.
Nicole, a community scientist in Portland, OR spent two years testing what attracts this elusive pest. After numerous trials, a Malbec wine from Argentina emerged as the top lure. The good news: Mason bees show no interest in it whatsoever.
Our new trap takes the research a step further. Two separate chambers let you test two different liquids side by side so you can compare your Malbec against another wine, a different lure, or plain water as a control.
The trap works best as part of a layered approach. Fall cocoon harvesting is still the single most powerful action you can take against the Houdini fly, and combining it with the trap during nesting season gives you year-round protection.
What’s included:
- Two-chamber trap body with perforated lid
- Mounting bracket (fits flat and hex bee hotels)
- Hardware for installation
Setup: Place inside the bee house if possible. Your trap fumes are able to concentrate vs outside and should work best there. The outer mounting bracket is easily removed. For outside of bee house, mount the bracket to the underside of your bee house, add your liquids, slide the trap in, and you’re done.
Two chambers allows you to experiment what attractant works for this pest. We think a cheap malbec has a front runner position. While apple cider/vinegar works for fruit flies, be careful of bycatch for non-Houdini flies.
Join the research: Run your own trials and tell us what you find at iNaturalist. We’ll share what the community discovers with the broader bee stewardship community.