SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
MINER BEES
Protandrena
MINER BEES
Genus Prondrena
Protandrena is a genus of small, usually dark-colored, non-metallic bees that often have pale markings on their faces, thoraxes and legs. The prefix prot means “earliest form of,” and Protandrena look like no-frills, tougher versions of Andrena. Protandrena have pitted heads and bodies that give them an armored appearance, and their facial foveae are smaller than those of Andrena and hairless. Male Protandrena lack the fuzzy look typical of many male Andrena.
Protandrena appear only in the Western Hemisphere. They are widespread throughout temperate North America, and they are diversely represented in Mexico and the western United States. Protandrena females are solitary ground-nesters that tend to build in sunny locations with sparse plant coverings. Protandrena waterproof their egg chambers, and often nest in aggregations.
Protandrena belong to the subfamily Panurginae, which also includes Perdita and Calliopsis. Unlike oxaeine bees and Andrena, shown in this guide's preceding sections, panurgines are “agglutinators” – that is, they add nectar to dry pollen and carry moist or partly-moistened pollen loads.
The forewings of Panurginae are distinctive and aid in separating them from other bees: the marginal cell of the panurgine forewing is lopped off at the tip and strongly bent away from the edge of the wing. The wings of Panurginae may have two or three submarginal cells.
TAXONOMY OF PROTANDRENA
Order: Hymenoptera
Family: Andrenidae
Subfamily: Panurginae
Tribe: Protandrenini
Genus: Protandrena
Species found at the NBC:
Protandrena (Protandrena) bancrofti
Protandrena (Pseudopanurgus) texana
Protandrena (Pterosarus) ornatipes
A female Texas protandrena (Protandrena texana)
TRAITS OF PROTANDRENA
Protandrena are small, dark bees with pitted, relatively hairless heads and bodies.
Protrandrena females often have pale markings on their faces -- the shape, size and color of such markings help to identify species.
Male Protandrena tend to have more extensive pale or yellow markings on their faces, mandibles and antennae than do females.
Protandrena Species of the National Butterfly Center
Fancy-footed protandrena
Protandrena (Pterosarus) ornatipes
Family: Andrenidae
Size: 6 mm (female and male)
Associated plant:
Camphor daisy
(Rayjacksonia phyllocephala)
Plant family: Asteraceae
When and where seen:
Nov. 9, 2021
Laguna Atascosa NWLR
Los Fresnos (Cameron Co.)
A female Protandrena ornatipes
The fancy-footed protandrena is a small, dark, green-eyed bee with yellow markings and fine, white and pale-brown hairs on its head, body and legs.
The female Protandrena ornatipes is robustly-built, with a dark-brown head and body. The female’s vertex, scutum and scutellum are finely pitted and covered with short, pale hairs.
The boomerang-shaped yellow mark on the female bee's face, which straddles the upper edge of the clypeus, is the best means of identifying females of this species.
The male fancy-footed protandrena is blackish-brown with a finely-pitted head and thorax.
The male bee has extensive lemon-yellow markings. This species’ name may derive from the appearance of the male bee’s lower tarsi, which are wide and conspicuous.
The male's face below the antennae, and its labrum, are yellow. The mandibles are yellow at the base, reddish in the middle and black at the tip. The antennae are mostly black: the front surfaces of the scapes are yellow, and the front surfaces of the flagella above F1 are dark brown.
A male Protandrena ornatipes
Protandrena ornatipes is an Asteraceae specialist that has both a spring and fall season in Texas. The bees shown here appeared in large numbers feeding on camphor daisy (Rayjacksonia phyllocephala) in the Bahia Grande Unit of Laguna Atascosa National Wildlife Refuge (Cameron Co.) in mid-November 2021.
The fancy-footed protandrena is a small, dark, green-eyed bee with fine, white and pale-brown hairs on its head, body and legs. This species is best recognized by the distinctive yellow markings on the female and male bees' faces. Males have extensive yellow markings on both the face and legs. The forewing of Protandrena ornatipes has two submarginal cells.
Protandrena ornatipes is widespread in Texas. The female of this species is sometimes misidentified as Protandrena renimaculatus, whose females have similarly small, although not identically-shaped, pale facial markings, and whose range is more northern. Close inspection under magnification and expert assistance may be required to verify identifications of this species.
Bancroft's protandrena
Protandrena (Protandrena) bancrofti
Family: Andrenidae
Size: 9-11 mm (female and male)
Associated plant:
Copper globemallow
Sphaeralcea angustifolia))
Plant family: Asteraceae
When and where seen:
June, 2021
El Mesteño Ranch
Puerto Rico (Hidalgo Co.)
A female Protandrena bancrofti
The female Protandrena bancrofti is broadly built, with a wide head and thorax. The thorax is sparsely haired, revealing a black, pitted surface.
The female Bancroft's protandrena has pale markings on the pronotal lobes and on the otherwise reddish-brown tegulae. Females may have an additional small pale spot on the small plate behind each tegula, and yellow spots on the bases of the front and middle legs' tibiae.
The front of the female bee’s thorax is rimmed with short, pale hairs.
Female (as well as male) Texas protandrena have richly-colored blue-gray eyes, a conspicuous trait that aids in field identifications of this species.
Bancroft’s protandrena is a black, medium-sized bee with an abdomen banded by pale hairs, reddish-brown wings and grey-blue eyes. It is large for a Protandrena.
The female Protandrena bancrofti is easily distinguished by its idiosyncratic ivory facial markings, which entomologist T.D.A. Cockerell described as “trilobed, the lobes acute, like a leaf”. The male Protandrena bancrofti (not shown here) is more slenderly-built than the female, and has pale-yellow markings on its lower legs. On the male bee, the pale facial mask is more extensive, and the labrum is yellow. The forewings of Protandrena brancrofti have three submarginal cells.
Bancroft’s protandrena appeared in early June 2021 at El Mesteño Ranch, located in Puerto Rico, Texas (Hidalgo County). There appear to be no prior records of this species in Hidalgo County, but Protandrena bancrofti is widespread in Texas, although relatively uncommon. Protandrena bancrofti occurs throughout the central United States, from the Mexican border to Canada. It ranges south as far as central Mexico.
Protandrena may be either generalist or specialist pollinators. Bancroft's protandrena has been documented feeding on a wide spectrum of flora, including nightshades, pea-family plants and Asteraceae. The female Bancroft’s protandrena shown here was found foraging on copper globemallow (Sphaeralcea angustifolia). Protandrena bancrofti is a vibratile (“buzz”) pollinator, an unusual trait among Andrenidae.
Texas protandrena
Protandrena (Pseudopanurgus) texana
Family: Andrenidae
Size: 7 mm (female)
6 mm (male)
Associated plant:
Texas palafox
(Palafoxia texana)
Plant family: Asteraceae
Sweetstem
(Aloysia macrostachya)
Plant family: Verbenaceae
When and where seen:
May-June, 2021
Falcon State Park
Roma (Starr Co.)
The female Protandrena texana is a hefty black bee with a pitted, nearly hairless, face and thorax.
The legs of the female Texas protandrena have ivory markings on the bases of the front and middle tibiae. The bees' lower legs are covered with dense white hairs.
Females carry pollen on long, feathery, dense, white scopal hairs located on their hind tibiae and basitarsi. The apex of each femur is covered by a dense tuft of short, white hairs.
Dorsal view of bee
A female Protandrena texana
Protandrena texana is a robustly-built small black bee with a broad head; a nearly hairless thorax with a densely pitted central area; faintly-defined bands of pale hairs on its abdomen; and black legs whose lower segments are covered with white hairs. Females carry pollen on long, feathery, white scopal hairs located on their hind tibiae and basitarsi.
Males of this species (not shown here) have faces that are primarily ivory on the lower half; extensive pale areas on their lower legs; and pale pronotal lobes. Both male and female Protandrena texana have distinctive rounded bosses (bumps) behind the top inner edges of each compound eye. The bees' forewings have two submarginal cells.
Protandrena texana may be very difficult to distinguish from similar bees which, like this species, formerly occupied the genus Pseudopanurgus. Species identification may require the assistance of an expert and frequently turns on such minute traits as the pitting on the bees’ thoraxes and abdomens, and the size and quality of the bossed areas behind the bees’ compound eyes.
Protandrena texana is widespread in southern Texas, although uncommon. It has been found as far west as New Mexico and ranges into Mexico at least as far south as Tamaulipas.
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Protandrena." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].