NOMAD CUCKOO BEES
Like the Epeolus and Triepeolus cuckoo bees shown on the previous page of this guide, Nomad bees are cleptoparasites of the bee tribe Nomadini.
Nomad bees lay eggs in the nests of ground-nesting bees -- most commonly, Andrena mining bees. When the nomad eggs hatch in Andrena nests, the nomad larvae – which have large, sickle-like mouth parts -- kill off the Andrena larvae and eat the provisions stored in the nest by the Andrena mother. According to The Xerces Society Guide to Attracting Native Pollinators, male nomad bees can imitate the scent of Andrenas and have the capacity to transfer this scent to female nomads during mating. This allows the female bees to sneak more easily into Andrena nests to hijack their food supplies.
Some nomad bees are generalists that parasitize the nests of multiple Andrena species. Other nomads target specific host species. The neighborly nomad bee, for example, targets the nests of hairy-banded mining bees (Andrena hirticincta). The spotted nomad bee (Nomada maculata), preys on the neighborly mining bee (Andrena vicina). The beautiful nomad bee (Nomada bella) is a cleptoparasite of Andrena imitatrix.
Nomad bees also exist that prey on Agapostemon, Halictus, and Lasioglossum sweat bees. Some nomad species target Colletes bees, long-horned bees in the genus Eucera or bees in the genus Melitta. The most common nomad species found at the National Butterfly Center, Nomada texana, is thought to parasitize the nests of Agapostemon sweat bees.
Species Identification Information:
Nomad bees are found throughout the world. There are nearly 300 nomad species in North America alone. Texas has a large array of Nomada. These include the Texas nomad bee like that shown below, as well as the Nomada vegana shown at top right.
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; striking, 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, Nomada texana, 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 (middle section), and its yellow facial mask. More detailed information on this species is given in the guide entry below.
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. (4) The jugal lobe of the nomad bee's wing is small.
Nomad 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 bee do, however, drink nectar from flowers. They tend to gather on the flowers visited by their hosts or to patrol the ground look for host bee nests.
Nomad Bees at the National Butterfly Center
At the National Butterfly Center, Texas nomad bees (Nomada texana) is by far the most common nomad species. Texas nomad bees are most visible in late fall, when they emerge to nectar on goldenrod. During this same period, the honey-tailed Agapostemon sweat bee (Agapostemon melliventris) -- this nomad's possible host -- appears in large numbers at the NBC.
A male Nomada vegana nomad bee
Nomad bees usually have black or red bodies with yellow or white markings on them. Their legs are often red or yellow.
Nomad bees may be predominantly black and yellow.
Or they may be red with yellow markings.
Or they may be all red, or red with black markings.
Nomad bees often have yellow antennal scapes and yellow markings on their faces.
The facial markings of male and female bees often differ within a species. This is the face of a male Nomada vegana.Typically, a male bee's face may have an extensive yellow mask, while the female has smaller yellow markings.
This is the face of a female Nomada vegana. Note that instead of a mask, the female's face has two relatively small yellow markings bordering her compound eyes.
The size, shape and location of markings on the nomad bee help to identify species.
The number, shape and continuity of the bands on the nomad bee's abdomen are also used as aids in identifying nomad species.
Characteristics of nomad bees
The honey-tailed Agapostemon, a possible host species for the Texan nomad bee
TAXONOMY OF NOMAD BEES
Species found at the National Butterfly Center
Nomad Bee Species of the National Butterfly Center
Nomada texana (female)
Size: 11 mm (female)
Associated plants at NBC:
A female Texas nomad bee
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).
Abdomen of a female Texas nomad bee: There are five continuous pale-yellow stripes on the bee's first through fifth abdominal segments (T1-T5).
The female bee's pronotum is black with yellow markings. The tegulae (where the wings attach) and pronotal lobes (just below the tegulae) are pale yellow.
The female bee's pronotal collar (the strip at the front of the thorax) is pale yellow.
There are yellow patches on the rear face of the propodeum, underscored by a yellow bar. These marks aid greatly in distinguishing the Texas nomad bee from most Texas nomad bee species.
The Texas nomad bee, Nomada texana, can be identified in part by its black body, red legs, reddish antennae and the yellow stripes on its abdomen and thorax. Among the most distinctive features of the bee are the two prominent yellow spots on the propodeum (the rear face of the thorax). The specific traits of this bee are noted in more detail in the photo strip at left.
The female bee shown here has two yellow marks on its face; the male Texas Nomad bee has a more extensive yellow mask covering most of its face. Such sexual dimorphism is common in nomad species.
According to Texas bee expert Jack Neff, Nomada texana, is a very common and widespread Texas species but little is known about its habits. It is thought to parasitize the nests of Agapostemon sweat bees.
A female Texas nomad bee