SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
NOMAD CUCKOO BEES
Nomada
NOMAD CUCKOO BEES
Genus Nomada
Tribe Nomadini
Like the Epeolus and Triepeolus cuckoo bees shown on the previous page of this guide, nomad bees are cleptoparasites (or brood parasites) belonging to the bee subfamily Nomadinae.
Nomad bees lay eggs in the nests of ground-nesting bees -- such as Andrena mining bees. When the nomad eggs hatch, the nomad larvae – which have large, sickle-like mouth parts -- kill off the host larvae and eat the provisions left for them by the Andrena parent.
Many Nomada parasitize the nests of multiple Andrena species. Others target specific host species. For example, the neighborly nomad bee (Nomada vicina) parasitizes the nests of hairy-banded mining bees (Andrena hirticincta). The spotted nomad bee (Nomada maculata) targets the neighborly mining bee (Andrena vicina). The beautiful nomad bee (Nomada bella) is a cleptoparasite of Andrena imitatrix. Some Nomada parasitize the nests of other bee genera.
Within the Lower Rio Grande Valley, Nomada tend to belong to the vegana species group -- this is the sole nomad bee group found in the neotropics. Its members parasitize the nests of Exomalopsis, Agapostemon and Nomia. The most common nomad species found in the Lower Rio Grande Valley, Nomada texana, is thought to lay its eggs in the nests of Agapostemon. The smaller Nomada guierezziae and Nomada vierecki are believed to target the small bees of the genus Exomalopsis.
Traits of Nomad Bees and Species Identification
Nomad bees are found throughout the world. There are nearly 300 nomad species in North America alone; at least 20 reside in Texas.
Nomad bees look wasp-like and tend to have the flashy appearance of custom-detailed race cars. They have sleek bodies, often adorned with well-defined stripes and crisp markings. They are usually red, black, yellow or a combination of these colors. Most nomad bees found in Texas have black or red bodies adorned with yellow markings; red or yellow legs; red, reddish-brown or partly yellow antennae; and red, green or brownish eyes.
General coloration varies from one type of nomad bee to another and can be used to help identify species. The Texas nomad bee, for example, can be identified in part by its black body, red legs, the yellow stripes on its abdomen, the yellow spots on its thorax, and its yellow facial mask.
Nomad bees have several distinctive minute traits that aid in identifying their genus: (1) the thoraxes of nomad bees are heavily pitted; (2) female nomad bees have specialized hair patches on the tips of their abdomens; (3) the pygidial plate (abdomen tip) of male nomad bees is pronounced and often notched; and (4) the jugal lobe of the nomad bee's wing is small. These traits are illustrated in the accompanying photo strip.
Pollinator Plants
Cuckoo bees do not gather pollen from flowers, because they obtain it instead by plundering other bees' nests. As a result, female nomad bees do not have scopae (pollen-collecting hairs) on their legs or abdomens. Nomad bees do, however, drink nectar from flowers. They tend to alight on flowers visited by their hosts or to patrol the ground looking for host bee nests.
A male Nomada vegana
Nomad bees have a wasplike appearance. They are slender, relatively hairless bees with bold markings.
The thoraxes of nomad bees are heavily pitted.
The marginal cell of the nomad forewing is sharply pointed. The jugal lobe (blue arrow) of the hind wing of the nomad bee is relatively small.
Characteristics of nomad bees
TAXONOMY OF NOMAD BEES
Order: Hymenoptera
Family: Apidae
Subfamily: Nomadinae
Tribe: Nomadini
Genus: Nomada
Species shown here:
Nomada gutierreziae (snakeweed nomad bee)
Nomada texana (Texas nomad bee)
Nomada vierecki (Viereck's nomad bee)
Nomada Species of the Lower Rio Grande Valley
Texas nomad bee
Nomada texana
Family: Apidae
Size: 11 mm (female)
9 mm (male)
Associated plants at NBC:
Seaside goldenrod
Solidago sempervirens
Romerillo
Bidens alba
(Family Asteraceae)
When found:
April - October
Common in Cameron, Hidlago
and Starr Counties
Nomada texana is a black bee with yellow markings and predominantly red legs.
The male Texas nomad bee has an extensive yellow mask on its face. Its antennae are mostly reddish. The front surfaces of the scapes are yellow. The bases of the bee's mandibles and its labrum are also yellow.
There are and two distinctive yellow marks on the male bee's rear thorax, underscored by a yellow bar.
A female Texas nomad bee
Dorsal view of bee
The female bee's head and thorax are predominantly black, with yellow markings. Its legs are red. The female bee has two pale-yellow marks on its face. (On male Texas nomad bees, a yellow mask extends over a much larger portion of the face).
A male Texas nomad bee (Nomada texana)
A female Texas nomad bee (Nomada texana)
The Texas nomad bee, Nomada texana, is a common and widespread Texas species, but little is known about its habits. As noted above, it is thought to parasitize the nests of Agapostemon. At the National Butterfly Center, Nomada texana are most visible during periods when Agapostemon melliventris appears in large numbers.
Nomada texana can be identified in part by its relatively large size and its black body, red legs, reddish antennae and the yellow stripes on its abdomen and thorax. Among the most distinctive features of this species (of both male and females) are the following. (1) Two prominent yellow nearly-rectangular areas, underlined by a broad yellow bar, appear on the bee's propodeum. (the rear face of the thorax). (2) There are are narrow, curved, pale-yellow lines on the sternum (on S3 and S4). These may be relatively small or extend slightly onto the sides of the abdomen. (3) On the upper abdomen, the yellow or pale-yellow stripe that crosses T3 is uninterrupted.
Males have more extensive yellow coloration on the face than females; this kind of sexual dimorphism is typical of many nomad bee species. The specific traits of this bee are noted in more detail in the accompanying photo strip.
Viereck's nomad bee
Nomada vierecki
Family: Apidae
Size: 7 - 8 mm (female and male)
Associated plants:
Arkansas dozedaisy
(Aphanostephus skirrhobasis)
Plant family: Asteraceae
When and where found:
May 29, 2021
Falcon State Park
Roma (Starr Co.)
April 26, 2023
Dos Venadas Ranch
Rio Grande City, TX (Starr Co.)
A female Viereck's nomad bee (Nomada vierecki)
Female nomad bee
Alternate view of bee
Dorsal view of bee
A male Nomada vierecki
A male Nomada vierecki: on male bees, T1-T6 are banded with uninterrupted pale-yellow stripes. On females of this species, T1-T5 are banded. T1 is often partly red on both males and females.
Dorsal view of male bee's thorax
A male Viereck's nomad bee (Nomada vierecki)
Viereck’s nomad bee is relatively uncommon in the Lower Rio Grande Valley. The distribution of Nomada vierecki is centered along the western half of the Mexico-United States border, in New Mexico, Texas and Chihuahua.
Nomada vierecki is a small dark-gray bee, with ivory and red markings and light- gray eyes. The extensive reddish coloring on the bee's body helps distinguish it from other Valley species: red usually appears on parts of the bee's head; its antennae; its legs; T1 of its abdomen; its propodeum; and much of the sternum. The sternum of both the male and female Nomada vierecki has distinctive curved pale-yellow lines on S3 and S4.
Viereck’s nomad bee is situated within the subgroup Micronomada, whose members parasitize the nests of small bees such as Exomalopsis and Halictidae. The male bee shown here was found on a cenizo bush mobbed by Exomalopsis birkmannni.
Associated plants:
Arkansas dozedaisy
(Aphanostephus skirrhobasis)
Plant family: Asteraceae
When and where seen:
April 26, 2023
Dos Venadas Ranch
Rio Grande City, TX (Starr Co.)
Snakeweed nomad bee
Nomada gutierreziae
Family: Apidae
Size: 7 - 9 mm (female and male)
A male gutierrezia nomad bee
Alternate view of bee
Face of male bee
Lateral view of thorax
A male snakeweed nomad bee
Nomada guierreziae is a small nomad bee thought to parasitize the nests of Exomalopsis. It can be most easily recognized by the combined red-and-yellow banding on its abdomen, and by the distinctive red markings lining the rear and top portions of its compound eyes. Males' faces have an unusual pattern of yellow markings that aid in their recognition. These traits are shown in the accompanying photo strip.
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Nomada." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].