SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
& THE TEXAS LOWER RIO GRANDE VALLEY
GUIDE INTRODUCTION
This guide contains information about native bees documented from 2018 to the present at the National Butterfly Center (NBC) of Mission, Texas.
In 2020, the guide's authors extended their research to cover bees of the Texas Lower Rio Grande Valley region, in which the NBC is situated. Notable species found in special habitats of the Valley are now also featured in this guide. New species are added each year.
THE WILD BEES OF TEXAS
The hundred-acre National Butterfly Center is located in Hidalgo County of the Lower Rio Grande Valley. This part of Texas reaches nearly as far south as the Florida Keys. Its climate is subtropical, and the Valley is thus home to many warm-climate bee species unknown in most of the United States.
The Lower Rio Grande Valley occupies a unique ecological niche: it contains eleven distinct habitats acclaimed for their biodiversity. The Valley harbors more than 1,200 documented plant species; hundreds of bird species; and distinctive mammals, among them the endangered ocelot. This environment also fosters extraordinary pollinator diversity: nearly 250 butterfly species have been documented at the National Butterfly Center alone, more than 150 of which are found only in the Lower Rio Grande Valley.
Bee populations at the National Butterfly Center are remarkably varied as well. The Lower Rio Grande Valley harbors a multitude of native bee species that specialize on blossoming plants peculiar to the region. The Valley's varied flora and long growing season also enable a broad spectrum of generalist bee species to thrive. The National Butterfly Center's proximity to canals and river beds makes it particularly well-suited to unusual bees that rely on nearby water sources to construct nests.
All of these factors conspire to make the National Butterfly Center a phenomenal wild bee hub. The ultimate goal of this website's Wild Bee Guide is to communicate both the unusual breadth of the world of Texas pollinators -- and to show how full of surprises that world is.
NOTABLE BEES OF THE NATIONAL BUTTERFLY CENTER
in September 2018, while conducting a survey at the National Butterfly Center, this website's authors, Paula Sharp & Ross Eatman, found and photographed a red-legged leafcutter bee unlike anything they had seen before.
World bee authority, John S. Ascher, Hadel Go of the American Museum of Natural History, and John L. Neff, Director of the Central Texas Melittological Institute, conferred over the leafcutter and agreed that it belonged to a subgenus that had never been encountered previously in the United States. This bee has been identified as Megachile (Tylomegachile) cf. toluca.
Many other bee species found at the NBC are rarely seen north of the Mexican border, or they are found exclusively or nearly exclusively in Texas. A sampling of these is shown in the accompanying photo strip: most visitors to the Lower Rio Grande Valley have never encountered such species as the Aztec cuckoo leafcutter, the apiform crooked-legged bee, the honey-footed Exomalopsis or the Melissoptila pinguis long-horned bee. Many other unusual wild bees appear in this website's pages.
The National Butterfly Center harbors several bee species of environmental concern. Among these is the American bumble bee (Bombus pensylvanicus). This pollinator has been categorized as a species of "greatest conservation need" under the Texas Conservation Action Plan. The International Union of Nature has placed the American bumble bee on its red list of vulnerable species.
OTHER NOTABLE BEES OF THE LOWER RIO GRANDE VALLEY
The Lower Rio Grande Valley is made up of Cameron, Hidalgo and Starr Counties, which border Mexico and the Rio Grande River on the south; and WIllacy County, situated directly north of Cameron County. All of these counties contain unique habitats and flora.
Among the many notable species of the Valley are the Mexican feather-tongued bee (Ptiloglossa mexicana), which emerges in early morning and late evening; the Totonac cuckoo leafcutter (Coelioxys totonaca), whose thorax is armed with three long spines; the rare Texas mesoxaea (Mesoxaea texana); the glorious protoxaea (Protoxaea gloriosa); the unusually large zacatec triepeolus cuckoo bee; and the beautifully-patterned discordant pebble bee.
INFORMATION ON AUTHORS, RESEARCH & IDENTIFICATION
Photographers Paula Sharp and Ross Eatman are the authors of the highly-regarded and well-traveled website, Wild Bees of New York, the culmination of a three-year project tracking and researching northeastern bee species. An exhibit of the authors' macro photography, titled Wild Bees, is currently on a national tour. Paula Sharp is the author of the forthcoming book Native Bees of the Texas Lower Rio Grande Valley, to be published by Texas A & M University Press in 2023.
Most Identifications of bees on this website are the product of the expertise and generous help of John L. Neff, Director of the Central Texas Melittological Institute. Dr. Karen Wright of Texas A & M University identified Svastra sabinensis.
The NBC project has been made possible by Jeffrey Glassberg, President of the North American Butterfly Association; by Marianna Trevino Wright, Executive Director of the National Butterfly Center; by Stephanie Lopez, NBC Native Plant Nursery Manager; and through the kind assistance of the NBC's impressive staff.
From 2020 to the present, the authors have conducted year-round bee surveys, pursuant to research permits, in regional Texas state parks, and federal land tracts and wildlife refuges. The authors also have conducted surveys, with permission, in local preserves and parks; in private ranches; and in hardscrabble areas such as vacant lots, road shoulders and railroad right-of-ways.
For more information on photographers Paula Sharp and Ross Eatman, visit this website's About page.

A Gulf fritillary butterfly at the National Butterfly Center

The Aztec cuckoo leafcutter bee: this chiefly Mexican species is rare in the United States.

A female crooked- legged bee entering an alamo vine blossom: this unusual species is seldom seen north of southernmost Texas.

A Melitoma marginella chimney bee: this beautiful inhabitant of the National Butterfly Center is ordinarily found only in subtropical areas.

A large population and recurrent population of the threatened American bumblebee (Bombus pensylvanicus) inhabits the National Butterfly Center.

A portly long-horned bee (Melissoptila pinguis).This scantily documented bee is the only member of its genus in the United States.

Griswold's carpenter bees are endemic to Mexico and southeastern Texas. They are frequent visitors to the NBC's gardens.
UNUSUAL BEES OF THE NATIONAL BUTTERFLY CENTER

The Texas mesoxaea (Mesoxaea texana) is among the rarest bee species in the United States.

The Texas mesoxaea (Mesoxaea texana) is also nearly an inch long, among the largest bees in the United States.

The related glorious protoxaea (Protoxaea gloriosa) is an uncommon, burly, red-legged bee with golden hair and green eyes.

The Mexican feather-tongued bee (Ptiloglossa mexicana) is most likely to be seen at dawn and sunset.

The Totonac cuckoo leafcutter (Coelioxys totonacus): this bee is the first of its species recorded in the United States: it appeared in Hidalgo County in 2021.

The beautiful discordant pebble bee (Dianthidium discors) constructs its nest partly from sand, pebbles or other debris. This is a predominantly Mexican species that appears in border regions of the United States.

The red-legged leafcutter, Megachile cf. toluca

An Aztec cuckoo leafcutter bee (Coelioxys azteca)
UNUSUAL BEES OF THE LOWER RIO GRANDE VALLEY