MELISSOPTILA LONG-HORNED BEE
In 1998, a prominent Brazilian entomologist criticized the only definitive study of Melissoptila long-horned bees available at that time: “The revision,” she wrote, “of the genus Melissoptila penned by Urban in 1968 was, lamentably, a publication of poor quality, with pages left blank, sentences illegible or cut in half, and endless typographical errors.” The entomologist denouncing this earlier publication was none other than Urban herself, returned thirty years later to reconquer the same territory.
Born in the Brazilian state of Parana in 1933, Danuncia Urban has been a trailblazer for women of science in Brazil. Over the course of her 60-year career, she discovered and documented 319 new bee species, founded the distinguished Entomology program at the Federal University of Parana and became a prominent taxonomist and authority on neotropical bees.
Much of Urban’s work has focused on long-horned bees. In 1998, Urban published a new, 46-page article on the genus Melissoptila, titled “New South American Species of Melissoptila Holmberg with Taxonomical Notes." Prior to her 1998 article, twenty-one species of Melissoptila had been documented; Urban now added another thirty-one. Urban's 1998 work remains the most comprehensive study of the genus Melissoptila to date.
What makes a long-horned bee a Melissoptila?
Long-horned bees are generally robust, with hairy bodies and long antennae. Five different genera of long-horned bees are featured in this website's wild bee guide -- Eucera, Florilegus, Melissodes, Melissoptila, and Svastra. (As of 2023, these genera are still in use, although recent phylogenetic studies suggest that a reorganization of long-horned bee taxonomy is imminent.)
How do Melissoptila differ from other long-horned bees? Entomologist Charles D. Michener described Melissoptila as similar to long-horned bees of the more commonly-known genus Melissodes. Michener noted, however, that Melissoptila tend to be smaller and that they can differentiated from Melissodes in part by the appearance of the bees’ abdomens. The abdomens of Melissoptila commonly lack well-defined bands and are covered with short, dense, tawny hairs. A notable trait of Melissoptila is that the stigmas of the bees’ forewings are shorter than the prestigmas (shown in the accompanying photostrip).
The genus Melissoptila was named by the Argentinean naturalist Eduardo Ladislao Holmberg during bee-collecting expeditions he conducted in South America in the late 1800's and early 1900's. Melissoptila means "fuzzy bee".
The species Melissoptila pinguis / Melissoptila otomita
Melissoptila is a neotropical genus -- that is, native to subtropical and tropical regions of the New World. The 52 Melissoptila species identified by Urban are found as far south as Argentinean Patagonia and Central Chile, and as far north as the Greater Antilles and the U.S. Rio Grande border. Since Urban's 1998 study, new Melissoptila have been documented only in Latin America, Hispaniola and Cuba.
Melissoptila pinguis is the sole species of the genus Melissoptila found in the United States. According to Michener, even this species is relatively rare in North America and, within the United States, appears principally in southernmost Texas. Melissoptila pinguis also has been documented in Mexico, Guatemala and Honduras.
Very little research on this unique species is widely available. The first published record of Melissoptila pinguis appeared in an 1878 article by entomologist Ezra Townsend Cresson titled “Descriptions of new species of North American bees.” The article’s description of the species was based on Cresson’s inspection of a single male specimen he encountered while traveling in Mexico.
Cresson placed the male bee in the long-horned genus Melissodes, naming it Melissodes otomita. He described the male bee as .35 inches long and black, with a head, thorax and legs clothed with mottled light and dark hairs; a pale yellow clypeus; and an abdomen whose second and third segments were covered with appressed (short and dense) golden-brown hairs. The bee’s tegulae (the plates where the wings meet the bee’s body) were black, and its wings were glassy with dusky outer margins. A notable feature of the male bee was that the sixth segment of the bee’s abdomen had a blunt tooth on each side.
Earlier in the same article, Cresson described a female bee, which he assigned to a separate species and named Melissodes pinguis. Like the male Melissodes otomita, the female bee measured .35 inches, and had short, dense golden-brown hairs on some segments of her abdomen; dark tegulae; and wings that were glassy with dusky tips. The veins on the female bee’s wings also resembled those of Cresson's male Melissodes otomita. (These traits are shown in the accompanying photographs.) With time, Melissodes otomita and M. pinguis would turn out to be the same species.
Cresson’s precise descriptions, now more than 140 years old, have proven impressively accurate: they describe to a tee the male and female Melissodes pinguis shown on this guide page.
After Cresson’s seminal article, Melissodes pinguis/otomita continued to find its way sporadically into the annals of entomological literature. In 1897, nearly twenty years after Cresson's publication, entomologist T. D. A. Cockerell included Melissodes pinguis/otomita in an article he titled “New and little-known bees.” He described both male and female specimens, placing both under the label “Melissodes pinguis.” Cockerell also filled out Cresson’s description of the female Melissodes pinguis, noting, among other attributes, that its abdominal hair was “like velvet”. Two years later, he included Melissodes pinguis in a catalog of the bees of Mexico.
Sixty years later, in 1957, entomologist Wallace E. LaBerge published a study of New World long-horned bees titled “The genera of bees of the tribe Eucerini in North and Central America”. In this study, he placed Melissodes otomita/pinguis in the genus Melissoptila and affirmed that Melissoptila otomita and Melissoptila pinguis belonged to a single species. LaBerge commented, in addition, that the male bee had toothlike projections on both its sixth and seventh abdominal segments. LaBerge discerned the same toothlike projections on the sixth segment of the female bee.
In her 1968 comprehensive description of the genus Melissoptila, Danuncia Urban linked Cresson’s two descriptions under one name, Melissoptila pinguis. (Since Cresson had described the female bee first, under entomological rules of naming, the pinguis technically trumps otomita.) This species nonetheles often appears in popular English-language databases and guides as Melissoptila otomita.
Melissoptila pinguis is assumed to be a solitary ground-nester. According to John L. Neff of the Central Texas Melittological Institute, there has been little reported research on the biology of members of the genus Melissoptila. Scanty information is available, for example, on the nesting habits of Melissoptila bees -- and there appears to be no published information whatsoever on Melissoptila pinguis, beyond descriptions of the bee’s appearance and apparent floral preferences.
Many Melissoptila species are pollen specialists. Several show a preference for members of the mallow family Malvaceae, particularly those of the genus Sida. A 2003 study by Viviane da Silva-Pereira, et al., detailed the novel behavior of the species Melissoptila thoracica feeding on Sida blossoms: female Melissoptila would settle on unopened flowers, and then face backwards, pressing their thoraxes against the blossoms and turning 360 degrees around the flowers’ anthers and stigmas. This behavior allowed the bees to gather pollen on their back legs as the Sida flowers gradually opened.
John L. Neff reports that he has encountered Texas specimens of Melissoptila pinguis feeding principally on mallows of the genus Wissadula. At the National Butterfly Center, female Melissoptila pinguis has been observed gathering pollen nearly exclusively from the mallow-family plant known as spiked malvastrum (Malvastrum americanaum var. americanum), whose flowers open in late afternoon. In early November, 2019, when spiked malvastrum began blooming at the National Butterfly Center, hundreds of female Melissoptila could be found at one time on a single stand of this plant.
Male Melissoptila pinguis have been sighted at the National Butterfly Center drinking nectar from cowpen daisy, a plant in the aster family that grows intermingled with spiked malvastrum at the NBC.
A female Melissoptila pinguis: This long-horned bee is the single species of its genus Melissoptila in the United States.
TRAITS OF MELISSOPTILA
A female Melissoptila: note that the bee's abdomen lacks bands, and is covered instead with short, golden hairs.
Compare this Melissodes long-horned bee (male): note the banded abdomen, a common feature of Melissodes.
Close-up of the appressed (short and dense) tawny hairs on the abdomen of a female Melissoptila.
A female Melissoptila pinguis
Detailed photographs of a female Melissoptila pinguis
A female Melissoptila pinguis: the female bee's abdomen is covered with dense gold hairs that Cresson described as looking "like velvet". Its hind-leg scopal hairs are long, lush and golden.
The female bee's thorax and legs are covered with light and dark hairs, making the thorax look gray to the naked eye.
Close-up of the first and second segments of the female bee's abdomen: note the shiny, bald, dark areas in the middle of T1 and (to a lesser extent) T2.
A male Melissoptila pinguis
Detailed photographs of a male Melissoptila pinguis
This male Melissoptila pinguis is 10 mm long. Its abdomen is banded with short golden hairs (with some some dark hairs).
The male Melissoptila pinguis has a yellow clypeus. Its antennae are longer than those of the female bee, a gender difference common in long-horned bees of many genera.
Dorsal view of male bee: when at rest, the bee holds its long antennae in a distinctive way, with the tips curling outward. Note that the bee's thorax is black.
Portly long-horned bee
Size: 10 mm (male and female)
Basic species characeristics: Look for short, dense golden hairs on the bee's abdomen; a thorax that appears gray from a distance; dusky forewings; (on the female) lush, golden scopal hairs on the bee;'s hind legs; (on the male bee) long antennae and a yellow clypeus; and (with the aid of a macro lens), toothlike lateral projections near the tip of the bee's abdomen.
Associated plants at NBC:
Plant Family: Malvaceae
Cowpen daisy (male bee only)
Plant Family: Asteraceae
October- November 2019, 2021, 2022
TAXONOMY OF MELISSOPTILA
Species found at National Butterfly Center:
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Melissoptila." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].