Cuckoo Carder Bees (Stelis) are rare kleptoparasites of other Megachilidae. Four species are known from the state, but they've each only been found a few times at most. Several other species are known from neighboring states and may also occur here. Also known as "Dark Bees".
Genus level ID: Most bees in this genus are small and dark with pale yellow spots and few hairs. ID from photos is possible, and since this genus is so rare, abundant and sharp photos are warranted if possible.
Similar Genera: Most likely to be confused with two of their host genera, Small Mason Bees (Genus Hoplitis) and Armored-Resin Bees (Genus Heraides).
Spot-sided Dark Bee (Stelis lateralis)
Perhaps the most common Stelis in VT, though still only a handful of records. Known hosts are Small Mason Bees (Genus Hoplitis).
Constrained Cuckoo Carder Bee (Stelis coarctatus)
First recorded in 2020 in Washington County. A parasite of Heriades carinata.
Federal Cuckoo Carder Bee (Stelis foederalis)
Two VT records - widely scattered in both time and space. Hosts include Osmia atriventris and Hoplitis spoliata.
Sixteen-spotted Cuckoo Carder Bee (Stelis permaculata)
One of the rarest bees in VT, only known from a single Addison County specimen. Very tiny.
Louisiana Painted-Dark Bee (Stelis louisae)
This boldly patterned species is so far unrecorded in VT, but one of its hosts the Bellflower Resin Bee (Megachile campanulae) is frequently found in on bellflowers around the state, including in gardens.
Unless otherwise specified, photos are courtesy of Margarita Miklasevskaja at PCYU with funding from NSERC-CANPOLIN.
Please note that many of our datasets have not been published yet, so the maps are incomplete.
