By Dirk Stevenson. Featured image: Southeastern sandhill cellophane bee. Photo credit: Dave Almquist/Florida Natural Areas Inventory.
Late last winter, South Georgia State College’s Frankie Snow and I were surveying for invertebrates on Alligator Creek Wildlife Management Area when we spotted a cluster of miniature mounds along an old woods road.
The mounds were actually the spoil from burrows dug in the sandy soil. They marked the work of an uncommon, poorly known and very interesting insect, the Southeastern sandhill cellophane bee.
Colletes ultravalidus was described from specimens collected in north and west Florida close to the Gulf Coast and from a single specimen found in 1997 near Hoboken in Brantley County, Georgia. Range-wide, there are only about dozen known sites. Alligator Creek WMA near Lumber City is the second in Georgia.
Why the Name?
Bees of the genus Colletes line the cells of their nests with a waterproof material that, when dry, resembles clear plastic. Accordingly, they are called “cellophane bees.” Some entomologists also refer to them as polyester or plasterer bees.
These odd little insects have unusual, forked tongues which they use to paint the plastic-like material onto their nest walls to keep the nests dry.
Cellophane bees are solitary creatures. They build individual nests in the ground, excavating long tunnels that exit through small round holes marked by a pile of soil (called tumuli). Yet despite their solitary nature, cellophane bees tend to build nests near one another, and groups of nesting bees may number in the tens of thousands. Still, they are not aggressive and do not form swarms.
They raise one generation a year and are mostly active in spring. The 17 species native to Georgia are all important pollinators of spring wildflowers and trees.
New Southeastern Species
First described in 2016 in the Journal of Melittology, the Southeastern sandhill cellophane bee is dark, golden-haired and about a half-inch long. That makes it a relatively large member of the Colletes genus but only about the size of a large worker honeybee.
It has an especially long cheek – called the malar by entomologists – and faint bands on its abdomen. (The similar blueberry cellophane bee, Colletes validus, has an extended malar, though not nearly as long as the sandhill’s, plus distinct bands on its abdomen.)
When it comes to nectar sources, both Southeastern sandhill and blueberry cellophane bees are thought to specialize on the tubular, urn-shaped flowers of native, early flowering ericaceous species, including blueberries. The distribution of the Southeastern sandhill cellophane also shadows that of the climbing fetterbush (Pieris phyllyreifolia), an odd heath species that, vine-like, scales the trunks of pond cypress. According to David Almquist, invertebrate zoologist with the Florida Natural Areas Inventory, the sandhill bee “forms nest aggregations in xeric, sandy sites adjacent to shrub bogs or cypress dome swamps, habitats where climbing fetterbush abounds.”
The population found on Alligator Creek was in a xeric longleaf pine/turkey oak sandhill community, a picturesque yet austere habitat type underlain by deep, droughty sands. Two bees believed to be Southeastern sandhill cellophane bees were also seen on climbing fetterbush flowers during early March at the WMA.
The Southeastern sandhill cellophane bee joins a growing list of odd and rare invertebrates – including the autumn tiger beetle, gopher tortoise burrow robber fly, Say’s spiketail dragonfly and Ohoopee geometer moth – documented on the xeric sand ridges along the WMA’s namesake Alligator Creek.
Dirk Stevenson is a naturalist and owner of Altamaha Environmental Consulting.