Masked Bees are tiny black and yellow bees found statewide from the spring through early fall. They have very few hairs and carry their pollen internally, making them appear more like wasps than other bee genera.
As of January 2021, 10 species in the genus Hylaeus have been recorded in Vermont, 5 of which have been confirmed through iNaturalist.
Genus level ID
Once you notice this genus, they can be easily found in a variety of habitats throughout the summer. Queen Anne’s Lace and other umbelliferous flowers are great places to find them. Males and females are easily separated by the pattern of yellow on the face, and unlike many bee genera, males are generally easier to ID.
The vast majority of Masked Bees you are likely to encounter in the state belong the Modest Masked Bee (H. modestus) group. Females of this group are impossible to separate, even with the specimen in hand, and males can be quite variable, but some experts feel they can be reliably separated by the extent and pattern of yellow, with a yellow mark on the tegula indicating Eastern Masked Bee (H. affinis).
The four most distinctive Masked Bees are all quite rare and localized in VT. The two species with red abdomens are wetland specialists known only from one site each on Lake Champlain. The Cinquefoil Masked Bee has thus far only been found in the heart of the Northeast Kingdom, though could occur in other cold pockets. It’s significantly larger than other species – with the females lacking yellow entirely and the males having bizarrely swollen antenna bases. The Slender-faced Masked Bee (Hylaeus leptocephalus) is likely an introduced species, and has distinctive white marks in place of the yellow, it has now been found human in dominated landscapes in several counties.
Vermont's Masked Bees
Modest Masked BeeHylaeus modestus
Eastern Masked BeeHylaeus affinis
Annulate Masked BeeHylaeus annulatus
Mesilla Masked BeeHylaeus mesillae
Cinquefoil Masked BeeHylaeus basalis
Nelumbo Masked BeeHylaeus nelumbonis
Ornate Masked BeeHylaeus ornatus
Slender-faced Masked BeeHylaeus leptocephalus
Species not included:
Vertical Masked Bee (Hylaeus verticalis) – Perhaps not recorded in VT in at least the past 50 years. Females have limited yellow marks, but this species is unlikely to be confirmed from photos.
Hylaeus illinoisensis – Nearly identical to the Modest Masked Bee, some experts do not recognize this as a valid species, though a handful of specimens have been identified from VT.
Broad-faced Masked Bee (Hylaeus sparsus) – This species is widespread in Eastern North America, but rarely collected anywhere. The one VT record is from Poultney VT on 6/5/2020. Visually similar to H. modestus, females of this species have a distinctive spine at the base of there front legs that is probably impossible to photograph on a live bee.
Please note that many of our datasets have not been published yet, so the maps are incomplete. Unless otherwise specified, photos in the grid are courtesy of Margarita Miklasevskaja at PCYU with funding from NSERC-CANPOLIN.