SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
GOBLIN BEES
Macrotera
GOBLIN BEES
Genus Macrotera
The bee subtribe Perditina harbors two genera of small-to-tiny bees: Perdita (shown in this guide's preceding section), and Macrotera. Perditina are found only in North and Central America, and they occur predominantly in arid regions of Northern Mexico and the southwestern United States.
Until relatively recently, the genus Macrotera was grouped together with Perdita. Now, however, Macrotera forms its own genus, made up of approximately 31 species. Macrotera are non-metallic small bees that differ physically from Perdita in the structure of their wings and mouthparts; their coloration; and attributes of the male bees’ heads.
Macrotera are solitary bees that nest in the ground. Unlike Perdita, Macrotera line their nests with a water-repellant secretion. Most Macrotera are oligolectic. Many species are specialist pollinators of globemallow or cactus. Most Macrotera of Texas belong to the subgenus Cockerellula and are associated with prickly pear cactus.
Traits of Macrotera
Males and female Macrotera are small to tiny bees. They are non-metallic, often with dark heads and thoraxes. In Texas, both males and females may have dark or red abdomens. Males of some Macrotera species have yellow markings on the pronotal lobes; some have yellow heads or yellow bodies. More commonly, males are dark-bodied, with yellow markings on the face and mandibles. Females usually have dark heads and lack yellow markings.
Males of some Macrotera species have broad, oversized, squarish heads and proportionately large, curved jaws. These traits may have earned them the name Macrotera, which translates from Greek to “great monster.” Within a given species, male head size may vary considerably. Females have proportionately-sized heads. The eyes of males and females are usually dark or bluish-gray.
Macrotera species of Texas
Documented sightings of Macrotera in Texas have been sporadic and infrequent. At least 14 species have been found in Texas in the last 100 years. Most belong to the subgenus Cokerellula, among them, Macrotera bidenticauda, M. knulli, M. lauticada, M. lobata, M. opuntiae, and M. robertsi. Other Texas species include: Macrotera (Macroterella) mellea, M. (Macrotera) crassa, M. (Macrotera) texana, M. (Macroteropsis) haplura, M. (Macroteropsis) latior, M. (Maroteropsis) portalis, and M. (Macroterella) mellea.
A female Macrotera (Cockerellula)
TRAITS OF MACROTERA
Many Macrotera of the Lower Rio Grande Valley have red abdomens and darkly-colored heads and thoraxes.
A female Macrotera (Cockerellula)
Male Macrotera of the Lower Rio Grande Valley may have oversized heads and large curved mandibles.
TAXONOMY OF MACROTERA
Order: Hymenoptera
Family: Megachilidae
Subfamily: Panurginae
Tribe: Perditini
Subtribe: Perditina
Genus: Macrotera
Species shown on this page:
Macrotera (Cockerellula) lobata
Macrotera of the Lower Rio Grande Valley
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Macrotera." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].
Lobed goblin bee
Macrotera lobata
Family: Andrenidae
Size: approx 4.5 mm (male and female)
Associated plants:
Texas prickly pear
(Opuntia engelmannii)
Plant family: Cactaeae
When and where seen:
April 26, 2023
Dos Venadas Ranch
Rio Grande City (Starr Co.)
A male Macrotera lobata
A male Macrotera lobata
Males of this species have disproportionately-large heads, pale-yellow masks covering the face below the antennae; and oversized pale-yellow mandibles.
Alternate view of head and mandibles
A female Macrotera lobata
This is a female Macrotera lobata found mating with the male bee above
The female's head and thorax are brown with hints of blue-green. Its abdomen is red.
Females have proportionately-sized heads. T
Sightings of Macrotera lobata in Texas are relatively rare. There is a March 30, 1946 record of this species in Mission Texas; and a March 28, 1950 record from Starr County, Texas. Macrotera lobata has also been documented in Cohuila Mexico: John L. Neff reported the species in March 26, 1992 in San Pedro de las Colonias; and Douglas Yanega reported a specimen found two miles north of San Lorenzo, on March 24 of the same year. Both Neff and Yanega found their specimens on Opuntia (prickly pear).
Macrotera lobata males are dark bees with greenish-blue heads and thoraxes, red abdomens, pale-yellow facial masks, oversized heads and disproportionately large yellow mandibles. They are distinguished by a combination of traits that require magnification to verify. These include details of the rearmost segment of the abdomen (T7); of the first segment (S1) of the sternum; and of the hidden genitalia. The name "lobata" derives from the fact that on males of the species, T7 is grooved medially, the groove terminating at the rear edge into two lobes on either side.
Females of the subspecies Cockerulla are so similar that they cannot be distinguished by visual comparison. The best means of identifying females is to apprehend them while mating with more easily identified males.
The male and female Macrotera lobata shown here were found on the blossoms of Texas priclky pear (Opuntia engelmanni). This website's authors have found other Macrotera (Cockerulla) in Starr County, feeding on pitaya cactus (Echinocereus enneacanthus) and peyote cactus (Lophophora williamsii).