Houdini-fly
Guides
Cacoxenus
Houdini fly
Cacoxenus is a genus of small fruit flies (Diptera: Drosophilidae) whose members are kleptoparasites of solitary bees. The best-documented species, C. indagator, infests nest cells of mason bees (Osmia spp.), laying eggs in pollen provisions intended for bee larvae. Larvae consume the pollen stores and frequently kill the host bee larvae. The common name "Houdini fly" refers to the larvae's ability to escape through mud nest partitions by gnawing exit holes. The genus has been introduced outside its native European range, including North America, where it threatens managed solitary bee populations.
Cacoxenus indagator
Houdini fly
Cacoxenus indagator is a kleptoparasitic fruit fly native to central and southern Europe that has been introduced to North America. Females lay eggs in the pollen-filled nest cells of cavity-nesting solitary bees, particularly mason bees (Osmia species). The larvae consume pollen stores intended for host bee larvae, causing host mortality or reduced adult size. The species is commonly called the "Houdini fly" for its ability to escape sealed nest cells. It poses a significant threat to managed solitary bee populations in commercial pollination operations.