Against which intruders do male Wool Carder Bees aggressively defend their territory?

Other male Wool Carder Bees, as well as other large flying insects, including hoverflies, wasps, and honeybees.

Male Wool Carder Bees are notably zealous territorial guardians, setting up watch posts to protect flowering patches that attract receptive females. Their defense mechanism is broad-spectrum, targeting any perceived aerial trespasser entering their established domain. This means their aggressive pursuit behavior is directed not only towards rivals of their own species (other males) but also encompasses a range of other large flying insects that might share the airspace. Specifically noted intruders that trigger a chase response include common garden insects like hoverflies, various types of wasps, and managed honeybees, demonstrating a broad defense perimeter.