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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

SVASTRA  LONG-HORNED  BEES
Svastra / Epimelissodes

SVASTRA LONG-HORNED BEES
Genus Svastra - Genus Epimelissodes

 

​​​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.

The genus Svastra, as defined until quite recently, was thought to range from southern Canada through Mexico and into temperate South America.

Characteristics of Svastra

Svastra 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 Svastra has a dark clypeus (the face-part above the mandibles), while the male has a yellow clypeus, clearly visible to the naked eye. 

Svastra 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 five Svastra species on this page reach such a size:  Sabine's long-horned bee (Svastra sabinensis), the frisky long-horned bee (Svastra petulca) and the black-legged long-horned bee (Svastra atripes).   In the field, these bees' hefty size and build makes them easily recognizable as Svastra. The Texas long-horned bee (Svastra texana), however, is modest in size, usually no more than half an inch long, and the barrel cactus Svastra is not much larger than a honey bee.

Other general traits aid in identifying regional Svastra. The antennae of male Svastra 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:  Svastra females have a tuft of long hairs in the middle of the metanotum (located near the back of the thorax).  This trait is shown in the accompanying photo strip.

 

Renaming of North American Svastra

Long-horned bee taxonomy is currently in a state of flux.   A recent analysis by Freitas et al (2023) places North American species of Svastra in the genus Epimelissodes.

Bee behavior and pollination practices

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

Svastra are best known for their prowress as sunflower pollinators.  Most Svastra of the Lower RIo Grande Valley belong to the subgenus Epimelissodes and forage principally on aster-family plants.  Among these are the Sabine's long-horned bee (Svastra savinensis), the frisky long-horned bee (Svastra petulca) and the Texas long-horned bee (Svastra texana).

The black-legged long-horned bee (Svastra atripes) is a vibratile (“buzz”) pollinator, unlike the many Svastra that are Asteraceae specialists.  Svastra 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 Svastra species are specialist pollinators of cactus.  Among these is the barrel cactus long-horned bee (Svastra duplocincta).  This is the sole Svastra that belongs to the subgenus Idiomelissodes.

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

A female Svastra sabinensis

TRAITS OF SVASTRA

TAXONOMY  OF  SVASTRA / EPIMELISSODES

Order:   Hymenoptera

Family:   Apidae

Subfamily:  Eucerinae

Tribe:  Eucerini

Genus:   Svastra
Species shown below:

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

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

     Svastra (Idiomelessodes) duplocincta (Barrel cactus long-horned bee)

Recommended reading: 

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.

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.   

REFERENCES

Svastra Species of the National Butterfly Center

Frisky long-horned bee
Svastra (Epimelissodes) petulca

or Epimelissodes (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 

Svastra petulca; (c) Copyright 2019 Paula Sharp

A female Svastra petulca

Svastra petulca;  (c) Copyright 2019 Paula Sharp

A female Svastra petulca from above

The frisky long-horned bee is the most common member of the genus Svastra 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.  Svastra 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 Svastra

Svastra (Epimelissodes) atripes

or Epimelissodes (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.)

Svastra atripes; Copyright 2023 Paula Sharp

A female Svastra atripes (dark morph)

Svastra atripes; Copyright 2023 Paula Sharp

A  male Svastra atripes

Svastra atripes is easily distinguished from other Svastra 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.  Svastra 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 Svastra 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
Svastra (Epimelissodes) sabinensis

or Epimelissodes (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.)

Svastra sabinensis; Copyright 2021 Paula Sharp

A female Svastra sabinensis

Savastra sabinensis; Copyright 2021 Paula Sharp

A male Svastra sabinensis

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

 

Svastra sabinensis ranges west to California, north to Colorado and south into Mexico.   This species is associated with aster-family flowers.  Svastra sabinensis is the host of the cuckoo bee Triepeolus penicilliferus.

Texas long-horned bee
Svastra (Epimelissodes) texana

or Epimelissodes (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.)

Svastra texana; Copyright 2022 Paula Sharp

A female Svastra texana

Svastra texana; Copyright 2022 Paula Sharp

A female Svastra texana

Svastra texana is uncommon in the Valley.   This species runs smaller than similar regional Svastra with banded abdomens, such as Svastra petulca.  Female Svastra 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 Svastra 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
Svastra (Idiomelissodes) duplocincta

or Epimelissodes (Idiomelissodes) duplocincta

Family:  Apidae

Size:  10 mm (female)

            8-9 mm (male)

Svastra duplocincta; Copyright 2022 Paula Sharp

A female Svastra duplocincta

Svastra duplocincta; Copyright 2022 Paula Sharp

Rear view of a female barrel cactus long-horned bee

Svastra duplocincta, the sole member of its subgenus Idiomelissodes, is the smallest of any of the Svastra 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 Svastra 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.  "Svastra."  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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