SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
EPIMELISSODES LONG-HORNED BEES
Epimelissodes
EPIMELISSODES LONGHORN BEES
Epimelisodes (formerly Svastra)
EPIMELISSODES LONGHORN BEES
Genus Epimelissodes (formerly called Svastra)
Until recently, the Epimelissodes longhorn bees appearing on this page were known as Svastra. The genus Svastra was first documented by the Argentinean naturalist Eduardo Ladislao Holmberg, a prolific science writer, author of science fiction and director of the Buenos Aires Zoological Gardens.
In the late 1800’s and early 1900’s, Holmberg, at times forsaking his longstanding interest in spiders, undertook a series of bee-collecting expeditions into the mountains of Argentina and the wilds of neighboring South American nations. He encountered diverse longhorn bee species and named the genus Svastra (Sanskrit for “sister”), remarking on its similarity to its sister genus Melissoptila, which he too had named.
For most of its history, the genus Svastra was thought to range from southern Canada through Mexico and into temperate South America. However, new phylogenetic studies clarifying the evolutionary history of various longhorn bee genera have resulted in the reclassification of North American Svastra. They have now been reassigned to their own genus: Epimelissodes (Dorchin et al. 2018; Freitas et al. 2023)
Nonetheless, Svastra and Epimelissodes continue to share many characteristics that aid in their identification. These traits are illustrated in the accompanying photo strip showing North American Epimelissodes.
Characteristics of Epimelissodes.
Epimelissodes are generally husky bees, with hairy thoraxes, faces and legs. The bees' abdomens are often banded by dark-and-pale hairs or, less commonly, covered with short golden hairs or dark hair. The female has a dark clypeus (the face-part above the mandibles), while the male has a yellow clypeus, clearly visible to the naked eye (LaBerge 1956).
Epimelissodes are differentiated from Melissoptila, Melissodes and other longhorn bee genera in part by size. In Bees of the Eastern United States, T.B. Mitchell described Svastra generally as robustly built, noting that some of them were nearly as large as queen bumble bees (measuring up to 20 mm or 3/4 inches) (Mitchell 1962).
Three of the Epimelissodes species on this page are notably large for longhorn bees: Sabine's longhorn bee (E. sabinensis), the frisky longhorn bee (E. petulcus) and the black-legged longhorn bee (E. atripes) and the oblique longhorn bee (E. obliquus) In the field, these bees' hefty size and robust build make them easily recognizable as Epimelissodes.
Other general traits aid in identifying regional Epimelissodes. The antennae of males are relatively short for longhorn bees, ordinarily reaching no farther than the first segment of the bee’s abdomen. Mitchell (1962) wrote that Svastra females could be best distinguished from other longhorn bee genera by a single trait, visible to the naked eye: females have a tuft of long hairs in the middle of the metanotum (located near the back of the thorax). This trait is illustrated here in the accompanying photo strip showing North American Epimelissodes.
Bee behavior and pollination practices
Like most longhorn bees, Epimelissodes nest in the ground. They are typically solitary, but sometimes build nests close to one another in large groups. Epimelissodes sabinensis and S. obliquus females, for example, share nests with one another: each bee provisions her own egg chambers with food stores for her offspring, while jointly excavating tunnels and nest entrances with other Epimelissodes (Rozen 1964, 1983). Males often sleep together in groups called aggregations, near nesting areas or pollinator plants.
Epimelissodes are best known for their prowess as sunflower pollinators. Most Epimelissodes of the Lower RIo Grande Valley forage principally on aster-family plants. Among these are Sabine's longhorn bee (E. sabinensis), the frisky longhorn bee (E. petulcus), the Texas longhorn bee (E. texanus) and the oblique longhorn bee (E. obliquus).
The black-legged longhorn bee (Epimelissodes atripes) is a vibratile (“buzz”) pollinator, unlike the many Epimelissodes that are Asteraceae specialists. Epimelissodes atripes is known to visit a range of flora. In the Valley it is often associated with shrubby blue salvia (Salvia ballotiflora), a plant in the mint family.
A few Epimelissodes species are specialist pollinators of cactus. Among these is the barrel cactus longhorn bee E. duplocinctus. This is the sole Epimelissodes that belongs to the subgenus Idiomelissodes.
EPIMELISSODES LONGHORN BEES
Epimelisodes (formerly Svastra)
A female Epimelissodes sabinensis
TRAITS OF EPIMELISSODES
Epimelissodes generally look "furry" -- hairs densely cover their heads, bodies and legs.
Female Epimelissodes have bushy scopal hairs on their hind legs.
Here is a close-up of the feathery pollen-collecting (scopal) hairs on the hind leg of a female Epimelissodes.
Epimelissodes have robust builds. Their heads and thoraxes are often covered with pale or golden hairs. The hairs on their legs vary in color: some have black leg hairs, like the female bee shown here.
Some Epimelissodes are entirely covered with pale or golden hair.
More often, the legs of Epimelissodes sport blond or golden hairs, while their bodies are covered with a mixture of light and dark hairs.
Male Epimelissodes duplocinctus aggregating on a plant stem
Photo copyright 2024 Marleigh Fletcher
TAXONOMY OF EPIMELISSODES
Order: Hymenoptera
Family: Apidae
Subfamily: Eucerinae
Tribe: Eucerini
Genus: Epimelissodes (formerly Svastra)
Species shown below:
Epimelissodes (Epimelissodes) atripes (Black-legged longhorn bee)
Epimelissodes (Epimelissodes) obliquus (Oblique longhorn bee)
Epimelissodes (Epimelissodes) petulcus (Frisky longhorn bee)
Epimelissodes (Epimelissodes) sabinensis (Sabine longhorn bee)
Epimelissodes (Epimelissodes) texanus (Texas longhorn bee)
Epimelissodes (Idiomelissodes) duplocinctus (Barrel cactus longhorn bee)
Epimelissodes Species of the Lower Rio Grande Valley
Frisky longhorn bee
aka Broad-banded longhorn bee
Epimelissodes (Epimelissodes) petulcus
formerly Svastra (Epimelissodes) petulca
Family: Apidae
Size: 16 mm (female); 14 mm (male)
Associated flora at NBC:
Blanketflower
(Gaillardia pulchella)
Cowpen Daisy
(Verbesina encelioides)
Mexican hat
(Ratibida columnifera)
Common sunflower
(Helianthus annuus)
Plant Family: Asteraceae
When and where seen:
April through November
Common in Cameron, Hidalgo
and Starr Counties
A female Epimelissodes petulcus: females of this species are large, robust bees with bushy pale or orangish scopal hairs on their hind legs. Their abdomens are banded with pale hairs.
Dorsal view of female bee: the female's thorax is rimmmed with orange hairs. Although the scutum and scutellum look bald, they are in fact partly covered with black hairs.
Female Epimelissodes petulcus have dark faces covered with pale hairs, and dark mandibles.
A female Epimelissodes petulcus
A female Epimelissodes petulcus shown from above
A male Epimelissodes petulcus
A male Epimelissodes petulcus -- note the bushy pale hairs on the bee's face.
The male bee has bright green eyes and a yellow clypeus. The base of each mandible is also pale yellow.
The frisky longhorn bee is the most common member of the genus Epimelissodes in the Lower Rio Grande Valley. It emerges in mid-spring and remains flying through late fall. It is most likely to be found on large-flowered members of the aster family -- including, for example, cowpen daisy, gaillardia and sunflowers. Epimelissodes petulcus is the only large bee at NBC that feeds on Mexican hat, a composite flower whose odd shape -- a tall brown column skirted by short orange petals -- makes an awkward landing pad for most big bees.
Sabine longhorn bee
Epimelissodes (Epimelissodes) sabinensis
formerly Svastra (Epimelissodes) sabinensis
Family: Apidae
Size: 14 mm (female and male)
Food plants at NBC:
Skeleton-leaf goldeneye
(Viguiera stenoloba)
Cowpen daisy
(Verbesina encelioides)
Plant Family: Asteraceae
Catclaw acacia (males)
(Senagalia greggi)
Plant Family: Fabaceae
When and where seen:
November 15, 2018
National Butterfly Center
June 18, 2021
Campos Viejos Ranch
Rio Grande City (Starr Co.)
April 16, 2023.
Dos Vendadas Ranch
Rio Grande City (Starr Co.)
A female Epimelissodes sabinensis feeding on skeleton-leaf golden-eye
A female Epimelissodes sabinensis: these impressive bees look like small lions. They have golden hairs on their thoraxes, abdomens and legs.
A female Epimelissodes sabinensis
A male Epimelissodes sabinensis
A male Epimelissodes sabinensis
The male bee has a yellow clypeus and mandibles that are yellow at the base. Its antennae are longer than the female's and darkly-colored. Note the male's reddish lower legs.
Epimelissodes sabinensis are magnificent longhorn bees, large and leonine and covered with golden hair. Copious pale and golden hairs cover the bees' heads and thoraxes, and their abdomen are clothed with short, tawny hairs. The eyes of both males and females are green.
Epimelissodes sabinensis lack distinct hair bands on the abdomen. Within Texas, Epimelissodes sabinensis is thurs fairly easily differentiated from other Epimelissodes. Other documented Texas Epimelissodes all have some pale or white banding on the abdomen. These include: Epimelissodes aegis, E. atripes, E. compta, E. grandissimus, E. machaerantherae, E. obliqua, E. petulcus and E. texanus.
Epimelissodes sabinensis ranges west to California, north to Colorado and south into Mexico. This species is associated with aster-family flowers. Epimelissodes sabinensis is the host of the cuckoo bee Triepeolus penicilliferus.
Black-legged longhorn bee
Epimelissodes (Epimelissodes) atripes
formerly Svastra (Epimelissodes) atripes
Family: Apidae
Size: 13-19 mm (females)
15-18 mm (males)
Associated flora:
Shruby blue salvia
Salvia balllotiflora
Family: Laminaceae
Cowpen daisy
Verbesina enceloides
Family: Asteraceae
When and where seen:
June 16-21, 2021
Puerto Rico TX (Hidalgo Co.)
Rio Grande City TX (Starr Co.)
A female Epimelissodes atripes (dark morph)
A female Epimelissodes atripes: this is an unusual dark morph of this species. On the typical female Epimelissodes atripes, the lower half of the thorax is covered with blond hairs, rather than black hairs.
Dorsal view of female's thorax
The legs of Epimelissodes atripes females are covered with bushy black hairs.
A male Epimelissodes atripes
The bee's thorax is covered with pale-brown hairs, its abdomen is banded by black and pale hairs, and its legs are covered with dense black hairs.
Dorsal view of thorax & vertex: note that the male's scutellum is fringed with a semi-circle of pale rust-brown hairs.
A male Epimelissodes atripes
Epimelissodes atripes is easily distinguished from other Epimelissodes of the Valley by the predominantly black hairs covering its hind legs and abdomen.
The black-legged longhorn bee is uncommon in the Valley, but it has been documented in all three of its border counties. Epimelissodes atripes has several subspecies variations. The female dark morph variation featured here is quite unusual. It appeared in mid-June in northwest Hidalgo County. It differs from the typical Epimelissodes atripes in having dark hair covering the lower half of its thorax and in having minimal white hairs on its abdomen.
The male bee shown here has more typical hair coloration for the species. It appeared in Starr County in late June 2021, buzzing around devil’s claw (Proboscidea louisianica).
Texas longhorn bee
Epimelissodes (Epimelissodes) texanus
formerly Svastra (Epimelissodes) texana
Family: Apidae
Size: 13-14 mm (female)
Associated Plants in
Lower Rio Grande Valley:
Camphorweed
(Heterotheca subaxillaris)
When and where seen:
November 2022
Weslaco, TX (Hidalgo Co.)
A female Epimelissodes texanus texanus
A female Epimelissodes texanus texanus: note that the hair below the bee's tegula is entirely pale.
Male E. texanus are very different in appearance from females -- males are covered predominantly with light-gold hairs. This photograph of the rarely documented male Epimelissodes texanus was made available through the Insects Unlocked program of the University of Texas. [Public domain photo by Alejandro Santillana; Wikimedia Commons]
Dorsal view of female Epimelissodes texanus texanus
Close-up showing dark hairs on female's scutum and scutellum (front thorax segments), and light hairs on vertex (top of head) and along the edges of the scutum and scutellum.
Face of female Texas longhorn bee: the female has a black face, short, dark antennae and blue eyes.
The female's hind-leg scopal hairs are mostly pale, but are orange on the basitarsi (lower legs). This is a distinguishing trait of females of the species.
A female Epimelissodes texanus texanus
Epimelissodes texanus is uncommon in the Valley: there are only a handful of documented regional sightings of this species, and all are for females. Epimelissodes tenanus typically ranges from California through the southwest, and eastward into north and central Texas, Oklahoma and Kansas. It is found as far south as northern Mexico (in Sonora, Chihuahua and Coahuila).
Female Epimelissodes texanus are best distinguished in the field from similar Epimelissodes by their size; by the generally pale appearance of hairs on the sides of the female's thorax; and by characteristics of the pale hair bands on their abdomens (shown in the accompanying photo strip).
The female Texas longhorn is a relatively small Epimelissodes, barely longer than a honey bee. Females have black faces, blue eyes, and short antennae. Pale hairs cover the female's head and the sides of the thorax (the mesepisternum) under the wing plates. The top of the thorax (scutum and scutellum) often bears a patch of dark brown hairs outlined with pale hairs, as shown on the bee pictured here. The female's front and mid legs are covered with mostly pale hairs, and the hind-leg scopal hairs are bushy and mostly pale-gold.
Male Epimelissodes texanus look very different from females. Males are covered predominantly by pale gold hairs (as shown in the photo strip). Males have green or grayish-yellow eyes, and the male clypeus (the face-part above the mandibles) is white or cream-colored. The patch of dark hairs on the male’s thorax is typically smaller, or a paler brown, than the female’s. Published photographs of male E. texanus are extremely rare. This may be in part because they are difficult to identify in the field; they are superficially similar to male E. sabinensis and to some variations of E. obliquus.
Geographical variation and subspecies. There are two subspecies of Epimelissodes texanus: E. texanus texanus and E. texanus elutus. Both are found in Texas. Epimelissodes texanus texanus are larger and darker overall and are found in the eastern part of the bees' range (Eastern Colorado, Kansas, Oklahoma and much of Texas as far south as Corpus Christi.) This is the subspecies that has been identified in the Valley. Among other traits, on female E. texanus texanus, the brown hair patch on the thorax is more extensive and distinct and darker than on E. elutus. Males have eyes that are gray or yellowish, rather than green.
Epimelissodes texanus elutus is found in desert areas of California, Arizona, northern Mexico and parts of west Texas (including El Paso). E. texanus elutus females and males often have red or partly red abdomens, and females may have red on the legs and thorax as well. On both males and females, the patch of dark hairs on the thorax is either paler than on E. texanus texanus or entirely absent. Males' faces have a pale triangular mark above the pale clypeus. This subspecies intermingles with E. texanus texanus; a continuum of specimens has been found showing an intermediate blend of the characteristics of E. texanus texanus and E. texanus elutus.
Despite subspecies differences, according to Wallace E. LaBerge (1956) Epimelissodes obliquus is distinguished from other Epimelissodes by the following minute traits, among others: (1) females have pale yellow to orange hairs on the inner surfaces of the hind basitarsi, and short, triangular bands of pale hairs on T2 (the second abdomen segment); and (2) males have thick pads of appressed (short, dense) hairs on the front of the mesepisternum (the sides of the thorax).
Floral associations: The Texas longhorn bee is associated with aster-family flowers. The female shown here was feeding in a large field of camphorweed in Weslaco, during late June of 2022.
Associated Flora
candy barrel cactus
(Ferocactus wislizeni)
Family: Cactaceae
When and where seen:
June 18, 2022
Rio Grande City (Starr Co.)
Barrel cactus long-horn bee
Epimelissodes (Idiomelissodes) duplocinctus
formerly Svastra (Idiomelissodes) duplocincta
Family: Apidae
Size: 10 mm (female)
8-9 mm (male)
A female Epimelissodes duplocinctus
A female barrel cactus longhorn bee (Epimelissodes duplocinctus)
This is a striking bee, with a boldly striped abdomen, grayish thorax hairs and bushy-haired hind legs.
Face of a female Epimelissodes duplocincta: females have black faces, grey-blue eyes and short antennae.
Rear view of a female barrel cactus long-horned bee
Aggregation of sleeping male barrel cactus longhorns. Photo copyright 2024 Marleigh Fletcher.
A group of male barrel cactus longhorn bees gathered together on a stem. [All images in this strip are Copyright 2024 Marleigh Fletcher.]
A male barrel cactus longhorn bee: note the overall grayish appearance of the male's head and thorax.
The male Epimelissodes duplocinctus has a tri-lobed yellow area on the clypeus, with a central lobe that points upward. The mandibles are also yellow at the base.
Male barrel cactus longhorn bee Photo copyright 2024 Marleigh Fletcher.
Svastra duplocincta, the sole member of its subgenus Idiomelissodes, is the smallest of the Epimelissodes featured on this guide page. The barrel cactus longhorn is readily identified by its size, its association with barrel cactus, and the boldly-defined, broad white bands of hair on its abdomen. The rear band of both female and male bees also has a distinctive shape – it peaks in the middle like the roof of a pagoda.
Range: The usual range of this species is California and Arizona, south through Mexico. The barrel cactus longhorn is rare in the Lower Rio Grande Valley. The female bee shown here was one of a group of females visiting candy barrel cactus at a Starr County ranch in June 2022.
Images of male bees shown here were contributed by photographer and naturalist Marleigh Fletcher, who photographed Epimelissodes duplocinctus in sleeping aggregations over a three-week period during August and September 2024, in Tempe, Arizona. These photos are provided here to aid in identifying male bees.
Description of species:
Both male and female barrel cactus longhorn bees have large, bulbous eyes. Females' eyes are blue-gray and males' typically light green. Females' faces, including the antennae, are usually brown or reddish-brown, with a dark clypeus (the face-part above the mandibles). On paler individuals, the clypeus, labrum (face-part below the clypeus) and base of the mandibles may be red. Males have a trilobed bright yellow area on the apical (bottom) half of the clypeus. On males, the base of the mandibles and the labrum are also yellow. Males' antennae (on F2-F10) are yellow-red in front and brownish red behind. This traits are shown in the accompanying photo strip.
On both males and females, pale hairs cover much of the dark integument of the thorax and vertex (top of the head), giving the bees an overall grayish appearance. Females have a mixture of black, grayish and brown hairs on the thorax which, according to entomologist Wallace E. LaBerge (1956) gives them "a curious mottled or streaked appearance".
The abdomens of females and males have apical bands of hair (that is, bands set on the rear rims of each segment). On females, these appear on T2-T4 (the second through fourth segments). On males, these appear on T2-T5. On both sexes, T2 has an additional pale hair band along the base; and the face of T1 is covered with long, pale hairs.
Behavior: Epimelissodes duplocinctus is most likely to appear where barrel cactus abounds. Males often can be found in early morning on plants located near cacti, sleeping in aggregations, a practice which, according to a 1998 study by entomologist John Alcock, gives the small Eumelisosdes some degree of protection against predatory assassin bugs. These aggregations are easily spotted, because of the bright banding on the male bees’ abdomens.
A male barrel cactus longhorn aggregation.
Photo copyright 2024 Marleigh Fletcher.
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Epimelissodes." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].