MELISSODES LONG-HORNED BEES
Long-horned bees belong to the tribe Eucerini and have unusually long antennae – hence the name "long-horned". Eucerini serve as essential pollinators for multi-million-dollar crop industries and include, among others, Svastra long-horned bees, instrumental in sunflower production; and Eucera long-horned bees that serve as key pollinators of melons and squash. The tribe Eucerini also includes Melissodes, a genus of irreplaceable pollinators of garden flowers, native wildflowers and sunflower crops.
All Melissodes are ground-nesters. The bees carve holes in the earth, where they construct individual nests containing brood cells lined with a waxlike material, each holding one egg and a single pollen ball. The nests, which may be isolated or built in groups, are frequently hidden under brush.
Female Melissodes tend to be easiest to find when they are out pollinating flowers. Males often rest hanging by their jaws from the stems of plants. In early morning, it is sometimes possible to surprise whole groups of male long-horned bees sleeping together in this manner.
Melissodes of the Lower Rio Grande Valley tend to be most abundant in summer and fall. Many, such as the mournful longhorned-bee (Melissodes tristis) and Tepanec longhorned bee (Melissodes tepaneca), are generalist pollinators. Some, like the coreopis long-horned bee (Melissodes coreopsis) show a preference for aster-family flowers; others specialize on such flowers as thistles, mallow and evening primrose.
General traits of Melissodes
Melissodes are robust, medium-sized bees with hairy heads and bodies. Females have prominent, bushy pollen-collecting scopal hairs on their back legs. Males have narrower builds than females; lack bushy hind-leg hairs; and usually sport much longer antennae. Both female and male Melissodes may have striking green or blue eyes; eye color within a given species may vary according to gender. In many Melissodes species, males have pale markings on the clypeus (the part of the face situated above the mandibles).
Texas has an exceptionally rich diversity of Melissodes long-horned bees. Melissodes of at least three distinct subgenera, each with its own special characteristics, are found within the Lower Rio Grande Valley. These subgenera include Eumelissodes, Melissodes and Tachymelissodes.*
* A recent phylogenic study of long-horned bees submerges the subgenus Tachymelissodes in the larger subgenus Apomelissodes. See Freitas et al. (2023).
A female Melissodes long-horned bee: note the bushy scopal hairs on the bee's back legs.
TAXONOMY OF MELISSODES BEES
Species shown below:
Melissodes (Eumelissodes) coreopsis (coreopsis long-horned bee)
Melissodes (Eumelissodes) tristis (mournful long-horned bee)
Melissodes (Melissodes) tepaneca (Tepanec long-horned bee)
Melissodes (Tachymelissodes/Apomelissodes) opuntiellus (prickly pear long-horned bee)
A male Tepanec long-horned bee of the subgenus Melissodes: note the very long "horns" (antennae) and the yellow clypeus.
Long-horned Bee Species of the Lower Rio Grande Valley
Tepanec Long-horned Bee
Melissodes (Melissodes) tepaneca
Size: 11 mm (male); 12 mm (female)
Food plants in the LRGV
Retama (a kind of Palo Verde)
Plant family: Fabaceae
Plant family: Verbenaceae
Plant Family: Asteraceae
September - April, 2018 -2023
National Butterfly Center
Found throughout Cameron, Hidalgo & Starr Counties
A female Melissodes tepaneca. This beautiful bee is the dominant Melissodes species of the Valley.
The female Melissodes tepaneca is best recognized inthefieldby its rust-red thorax hairs. On some individuals, the hairs are less-intensely colored.
A female Tepanec longhorn bee (Melissodes tepaneca)
A male Tepanec longhorn bee
A male Tepanec long-horned bee: males have green eyes and longer antennae than females. Note that the tips of the bee's antennae are not darker than the segments below them.
The yellow spots on the bases of the male bee’s mandibles, and the lack of dark coloration on its antennal tips, distinguish it from the similar male worthy longhorned bee (Florilegus condignus).
Little Prickly Pear Long-horned Bee
Melissodes (Tachymelissodes) opuntiellus
or Melissodes (Apomelissodes) opuntiellus
Size: 8 mm (female and male)
Associated plants at NBC:
Red prickly poppy
Plant family: Papaveraceae
Texas prickly pear
Plant family: Cactaceae
Plant family: Malvaceae (formerly Sterculiaceae)
When seen: March-April 2019, 2021
A female Melissodes opuntiellus on a cactus blossom: this species is easily distinguished from other regional longhorn bees by the combination of its relatively small size; its pale abdominal bands and pale thorax hairs; its bright blue eyes; and its association with cactus.
Female Melissodes opuntiellus have bright blue eyes and hind legs covered with bushy hairs. White hairs cover the bees' faces and thoraxes and band their abdomens.
A male Melissodes opuntiellus like females, males have bright blue eyes and boldly-defined pale bands on their abdomens.
The bee inside a red prickly poppy: in early spring in the Lower Rio Grande Valley, male Melissodes opuntiellus frequently can be found resting in prickly poppies.
A female Melissodes opuntiellus
A male Melissodes opuntiellus
A note on Melissodes opuntiellus: The species name "opuntiellus" is a reference to Opuntia, the scientific name for prickly pear cactus. The Latin suffix "ellus" is a diminutive ending. Thus this bee's name might translate as "the little prickly pear bee". During spring in the Lower Rio Grande Valley, male Melissodes opuntiella appear in large numbers on the flowers of Texas prickly pear cactus (Opuntia englemannii).
This species was first described by the entomologist T. D. A. Cockerell in 1911, in a one-page article titled "Some New Bees from Flowers of Cactaceae," shown below left, which appeared in Volume 35 of The Canadian Entomologist.
Prickly poppies in the Lower Rio Grand Valley begin flowering just before the bloom period of Texas prickly pear cactus. Male Melissodes opuntiellus appear on prickly poppy (Argemone sanguinea) in mid-March at the NBC and the surrounding area.
We have noted that various genera of male bees that feed on prickly pear flowers (including Lithugopsis and Diadasia) appear to use prickly poppies in the spring for shelter, without feeding on them. (Male bees drink nectar but do not gather pollen; prickly poppies produce pollen but very little nectar.) Possibly, the bees choose the poppies to rest in because they are comfortable and roomy and provide protection from wind and rain.
Females of this species have been documented on an array of plants including mallows and palo verde. In 1980, during a survey of sunflower pollinators, entomologists Hurd and LaBerge observed this species foraging on sunflowers. At the NBC, female bees have appeared on prickly poppies, prickly pear cactus and teabush.
Estero Llano Grande SP
Weslaco - Hidalgo Co.
THIS CONSTITUTES A RANGE EXTENSION FOR THIS SPECIES
Coreopsis Longhorn Bee
Melissodes (Eumelissodes) coreopsis
Size: 8.5 - 11 mm (male)
10 - 11 mm (female)
A female coreopsis longhorn bee (Melissodes coreopsis)
A female Melissodes coreopsis: this species is unusual in the Valley. The female bee stands out in the field, because it is covered almost entirely with pale hairs.
The bee's face is broad, and its antennae dark and relatively short. Its eyes are pale blue. Dense, pale hairs cover its face.
The bee's vertex hairs are predominantly pale, with a few dark-gray hairs. Female Melissodes coreopsis are similar to female Melissodes tristis (shown below in guide), but the latter lack dark hair on the vertex.
Dorsal view of female bee
A male Melissodes coreopsis
The hairs on the head and body of the male Melissodes coreopsis are entirely pale (except for some reddish hairs on inner surfaces of the tarsi).
Note that the hairs on the male bee's vertex and thorax are entirely white. Its antennae are relatively long.
Front view of male bee
A male coreopis longhorn bee
Dark labrum and mandibles of male bee
Mournful Long-horned Bee
or Dark-faced Long-horned Bee
Melissodes (Eumelissodes) tristis
Size: 9-12 mm (male)
10-14 mm (female)
Associated plants at NBC:
Shrubby blue sage
Plant family: Lamiaceae
Plant family: Fabaceae
April 2019, March 2020
A female mournful long-horned bee (Melissodes tristis) foraging on shrubby blue sage in Hidalgo County in April 2019.
A male Melissodes tristis on milkweed: the male Melissodes tristis has a black clypeus (the face-part above the jaws), an unusual trait for a male long-horned bee. The clypeus is hidden here behind a thatch of white facial hair. (Photograph copyright 2017 J. A. Winget).
A female Melissodes tristis from Hidalgo County: all of the hairs on the female and male bees' thorax and vertex are white.
A female mournful long-horned bee drinking nectar from shrubby blue sage: females of this species have notably wide faces.
Close-up of face of female bee: the bee has striking, denim-blue eyes, and a ridge on the bottom of its clypeus. This ridge helps distinguish females of this species from the similar female Melissode coreopsis (shown above).
A female Melissodes tristis on shrubby blue sage
A male Melissodes tristis (Photograph copyright 2017 J. A. Winget)
A female Melissodes tristis long-horned bee
As noted above, longed-horned bees of the subgenus Eumelissodes often specialize in pollinating composite flowers of the family Asteraceae such as sunflowers and daisies. The mournful long-horned bee, however, is a prodigious generalist that has been documented visiting the flowers of more than twenty plant families.
According to entomologist Wallace E. LaBerge, author of a comprehensive 1961 study of the genus Melissodes, the mournful long-horned bee is the most polyletic species of the subgenus Eumelissodes. Melissodes tristis has a remarkably long flight season, from March through November, and is able to adapt to an array of habitats with very different flora. LaBerge believed that this species produces as many as three generations per year in Texas.
Female Melissodes tristis appear in late March and early April at the National Butterfly Center as honey mesquite begins to bloom. Male bees have not been observed to date at the NBC. (The example shown here of a male bee was contributed to this website by nature photographer J. A. Winget, who found it in Grand Canyon Village, Arizona). Melissodes tristis is endemic to much of Texas, and to south central Mexico as far south as the state of Oaxaca. This species ranges through the southwestern United States and extends from western Oklahoma, Kansas and Nebraska through Colorado, Nevada, Utah, and southern Wyoming, into California and Oregon.
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Melissodes." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].