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ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER

Mission, Texas

SVASTRA  LONG-HORNED  BEES
Svastra / Epimelissodes

SVASTRA  LONG-HORNED  BEES
Svastra

Svastra sabinensis; Copyright 2021 Ross Eatman

EPIMELISSODES  &  SVASTRA  LONG-HORNED  BEES
Epimelisodes / Svastra

EPIMELISSODES or  SVASTRA LONG-HORNED BEES
Genus Epimelissodes - Formerly called Svastra

 

Until recently, the Epimelissodes long-horned 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 long-horned bee genera have resulted in the reclassification of North American Svastra.  They have now been reassigned to their own genus:  Epimelissodes. 

 

Nonetheless, Svastra and Epimelissodes continue to share characteristics that aid in their identification.

Characteristics of Svastra and Epimelissodes.

Svastra and 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. 

Svastra and Epimelissodes are differentiated from Melissoptila, Melissodes and other long-horned 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). 

Three of the Epimelissodes species on this page are notably large for laong-horned bees:  Sabine's long-horned bee (Epimelissodes  sabinensis), the frisky long-horned bee (Epimelissodes  petulca) and the black-legged long-horned bee (Epimelissodes atripes).  In the field, these bees' hefty size and robust build make them easily recognizable as Epimelissodes.

Other general traits aid in identifying regional Epimeliissodes. The antennae of males are relatively short for long-horned bees, ordinarily reaching no farther than the first segment of the bee’s abdomen.  Mitchell wrote that Svastra females could be best distinguished from other long-horned 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, shared by North American Epimelissodes, is shown in the accompanying photo strip.

Bee behavior and pollination practices

Like most long-horned bees, Svastra and Epimelissodes nest in the ground. They are typically solitary, but sometimes build nests close to one another in large groups.  Epimelissodes  sabinensis females also are known to 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.

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 the Sabine's long-horned bee (Epimelissodes sabinensis), the frisky long-horned bee (Epimelissodes petulca) and the Texas long-horned bee (Epimelissodes texana).

The black-legged long-horned 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 long-horned bee Epimelissodes duplocincta).  This is the sole Epimelissodes that belongs to the subgenus Idiomelissodes.

Epimelissodes sabinensis long-horned bee - (C) Copyright 2018 Paula Sharp

A female Epimelissodes sabinensis

TRAITS OF EPIMELISSODES

TAXONOMY  OF  EPIMELISSODES 

Order:   Hymenoptera

Family:   Apidae

Subfamily:  Eucerinae

Tribe:  Eucerini

Genus:   Epimelissodes (formerly Svastra)
Species shown below:

     Epimelissodes (Epimelissodes) atripes (Black-legged long-horned bee)

     Epimelissodes (Epimelissodes) petulca (Frisky long-horned bee)
     Epimelissodes (Epimelissodes) sabinensis (Sabine long-horned bee)
     Epimelissodes ( (Epimelissodes) texana (Texas long-horned bee)

     Epimelissodes (Idiomelissodes) duplocincta (Barrel cactus long-horned bee)

A note regarding the renaming of North American Svastra:  ​​A recent analysis by Freitas et al (2023) places North American species of Svastra in the genus Epimelissodes.

Recommended reading: 

Freitas FV, Branstetter MG, Franceschini-Santos VH, Dorchin A, Wright KW, López-Uribe MM, Griswold TL, Silveira FA, Almeida EAB. 2023. UCE phylogenomics, biogeography, and classification of long-horned bees (Hymenoptera: Apidae: Eucerinae), with insights on using specimens with extremely degraded DNA. Insect Systematics and Diversity 7(4), 3: 1-21.   

Dorchin A, López-Uribe MM, Praz CJ, Griswold TL, Danforth BN. 2018. Phylogeny, new generic-level classification, and historical biogeography of the Eucera complex (Hymenoptera: Apidae). Molecular Phylogenetics and Evolution 119:81–92.

REFERENCES

Epimelissodes Species of the National Butterfly Center

Frisky long-horned bee

Epimelissodes (Epimelissodes) petulca

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 

Epimelissodes petulca; Svastra petulca; (c) Copyright 2019 Paula Sharp

A female Epimelissodes petulca

Epimelissodes petulca; Svastra petulca;  (c) Copyright 2019 Paula Sharp

A female Epimelissodes  petulca  shown from above

The frisky long-horned 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 petulca 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.  

Black-legged long-horned 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.)

Epimelissodes atripes; Copyright 2023 Paula Sharp

A female Epimelissodes atripes (dark morph)

Epimelissodes atripes; Copyright 2023 Paula Sharp

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 long-horned 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).

Sabine long-horned 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.)

Epimelissodes sabinensis; Svastra sabinensis; Copyright 2021 Paula Sharp

A female Epimelissodes sabinensis

Epimelissodes sabinensis; Svastra sabinensis; Copyright 2021 Paula Sharp

A male Epimelissodes sabinensis

Epimelissodes sabinensis is a magnificent long-horned bee, large and leonine and covered with golden hair.  Copious pale and golden hairs cover the bees' heads and thoraxes, and their abdomens are clothed with short, tawny hairs.  The eyes of both males and females are green. 

 

Within Texas, Epimelissodes sabinensis is fairly easily differentiated from other Epimelissodes.  Other documented Texas Epimelissodes species include Epimelissodes aegis, E. atripes, E. compta, E. machaerantherae, S. obliqua, E.  petulca and E. texana.  Unlike Epimelissodes sabinensis, all have black abdomens striped with some pale banding. 

 

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.

Texas long-horned bee

Epimelissodes (Epimelissodes) texana

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.)

Epimelissodes texana; Copyright 2022 Paula Sharp

A female Epimelissodes texana

Epimelissodes texana; Copyright 2022 Paula Sharp

A female Epimelissodes texana

Epimelissodes texana is uncommon in the Valley.   This species runs smaller than similar regional Epimelissodes with banded abdomens, such as Epimelissodes petulca.  Female Epimelissodes texana are best distinguished by their size and  by traits of the pale hair bands on the bees' abdomens, as shown in the photo strip.  Females have blue eyes, a trait that aids in distinguishing them in the field from Epimelissodes petulca females, which have green eyes.  The Texas long-horned bee is associated with aster-family flowers.

Associated Flora

candy barrel cactus

(Ferocactus wislizeni)

Family:   Cactaceae

When and where seen: 

June 18, 2022

Rio Grande City (Starr Co.)

Barrel cactus long-horned bee

Epimelissodes (Idiomelissodes) duplocincta

formerly Svastra (Idiomelissodes) duplocincta

Family:  Apidae

Size:  10 mm (female)

            8-9 mm (male)

Epimelissodes duplocincta; Copyright 2022 Paula Sharp

A female Epimelissodes duplocincta

Epimelissodes duplocincta; Copyright 2022 Paula Sharp

Rear view of a female barrel cactus long-horned bee

Epimelissodes duplocincta, the sole member of its subgenus Idiomelissodes, is the smallest of any of the Epimelissodes featured on this guide page. The barrel cactus longhorn is readily identified by 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 (as shown in the accompanying photo strip). 

This bee is most likely to appear in the Valley 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 Epimelissodes some degree of protection against predatory assassin bugs. These aggregations are easily spotted, because of the bright banding on the male bees’ abdomens. 

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].

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