Waisted Beegrabber Physocephala rufipes
Taking it even a step further: the Thick-headed Flies belonging to the Physocephala genus. Not only are they black and yellow and have unusually long antennae, just like the Conops above, but they even have the typical wasp's waist, rarely encountered in flies. Reaching some 10 tot 18 mm it is about the same size as many of the wasps it imitates. The Waisted Beegrabber can be told apart from similar other species by the reddish legs. The species is not only a parasite to the Common Carder Bee, but to the Garden Bumblebee, the Earth Bumblebee and the Red-tailed Bumblebee as well. The sizes of the bumble bees the Waisted Beegrabber is a parasite to explains the variability in measures. Carder Bees are much smaller than Earth Bumblebees, hence the flies produced are also much smaller. This species is on the wing the same a time most of the Thick-headed Flies are: from mid-May to mid-August.
