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 genera 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. Four different genera of long-horned bees are featured in this website's wild bee guide -- Melissodes, Melissoptila, Svastra and Tetraloniella. The distinctive traits of each of these genera are highlighted in the photo strip at right.
Melissoptila long-horned bees are unusual in this group, because they are represented within the United States by a single species.
How do Melissoptila species 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, shown on the preceding page of this guide. 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 at right).
The genera 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 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, most recently in Hispaniola and Cuba (M. micheneri).
Melissoptila otomita is the sole species of the genus Melissoptila found in the United States. According to Michener, this species is relatively rare in North America and, within the United States, appears principally in southernmost Texas. M. otomita 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 otomita appeared in an 1878 article by entomologist Ezra Townsend Cresson titled “Descriptions of new species of North American bees.” The article’s description of M. otomita was based on Cresson’s inspection of a single male specimen he encountered while travelling 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 nodes 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 photographs at right and below.) With time, M. 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 otomita shown on this guide page.
After Cresson’s seminal article, Melissodes 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 otomita/pinguis 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 M. 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 affirmed that Melissodes otomita and Melissodes 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 now appears (perhaps erroneously) in English-language literature and databases as Melissoptila otomita.
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 otomita, beyond descriptions of the bee’s appearance and apparent floral preferences.
A handful of studies by Latin America entomologists, beginning in 1912 through the present, have furnished some useful and evocative information about the genus Melissoptila generally. Such studies show that Melissoptila are solitary bees, but that at least some South American Melissoptila species form large aggregations. A 1991 study by entomologists Moffat and Roig-Alsina reported that the Argentinian species Melissoptila pubescens nests communally. The authors encountered a nest in which a group of female Melissoptila pubescens shared both a common entrance-hole and a main tunnel that ran vertically underground, before dividing into smaller tunnels leading to individual bees’ separate chambers.
As a rule, adult males of solitary native bee species do not enjoy the comfort of nests. Males tend to sleep outside, often on flowers. Among some species, males may form groups called aggregations; in the United States, groups of male long-horned bees of various species sometimes can be found sleeping together on plants in early morning, suspended by their jaws, their legs pulled close around their abdomens. There is evidence that at least some Melissoptila engage in this practice. In 2014, a group of Brazilian biologists published a report that one species of Melissoptila (M. Melissoptila aff. bonaerensis) had been discovered sleeping in an aggregation commingled with the species Melissodes nigroaenea. Such behavior is unusual in the bee world, because male aggregations are customarily limited to bees of a single species.
Whether Melissodes otomita male and female bees engage in such behavior has yet to be established.
Various Latin American studies on the foraging habits of Melissoptila species confirm that many are pollen specialists. Some research into floral preferences of South American Melissoptila has focused on species that visit aster-family flowers. In 2010, for example, John Toretta et al. published an article describing the species Melissoptila tandilensis as a significant pollinator of sunflower crops in Argentina.
Several Melissoptila species show a preference for members of the mallow-plant 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 otomita feeding principally on mallows of the genus Wissadula. At the National Butterfly Center, female Melissoptila otomita have 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 M. otomita have been sighted occasionally drinking nectar from cowpen daisy, a plant in the aster family that grows intermingled with spiked malvastrum at the NBC.
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Melissoptila." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.sharpeatmanguides.com. Accessed [day/month/year guide accessed].
A female Melissoptila otomita: This long-horned bee species -- along with the entire bee genus Melissoptila -- is rarely seen in the United States.
A Melissodes long-horned bee (male): Note the banded abdomen, a common feature of Melissodes bees. Note also the bee's long antennae, the feature that earns this bee variety the name "long-horned".
A Melissodes long-horned bee (female).
Compare this female Melissoptila: Note that the bee's abdomen lacks bands, and is covered instead with short, light-gold hairs.
A male Melissoptila
A Svastra long-horned bee: This bee is almost twice the size of a typical Melissoptila. Its thorax as well as abdomen are covered with bushy golden hairs. Some Svastra species have banded abdomens.
A Tetraloniella long-horned bee. Note the long antennae of this male bee. Tetraloniella bees usually have banded abdomens. (As explained in the guide page on Tetraloniella, this genus was renamed in 2018.)
Examples of four genera of long-horned bees: Melissoptila, Melissodes, Tetraloniella and Svastra
Close-up of the appressed (short and dense) tawny hairs on the abdomen of a female Melissoptila.
On the forewing of Melissoptila bees, the prestigma (red arrow) is smaller than the stigma (blue arrow).
This is a rear view of a male Melissoptila otomita. Note the small, dark, toothlike projections near the tip of the bee's abdomen. Both male and female bees of this species share this trait. (On females, the teeth appear on the sixth segment (T6); on males they appear on both T6 and T7.)
Some traits of the genus Melissoptila
A female Melissoptila otomita
A female Melissoptila otomita: the female bee's abdomen is covered with dense gold hairs that Cresson described as looking "like velvet".
The female bee's wings are dusky, especially toward the tips.The bee's thorax and legs are covered with light and dark hairs.
Close-up of the first and second segments of the femlae bee's abdomen: note the shiny, bald dark areas in the middle of the segments.
Detailed photographs of a female Melissoptila otomita
A male Melissoptila otomita
Detailed photographs of a male Melissoptila otomita
This male Melissoptila otomita is 10 mm long. Its abdomen is banded with short golden hairs (with some some dark hairs).
The male bee's wings are smoky with black veins. There are light and dark hairs on its thorax and legs.
The male Melissoptila otomita 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.
Melissoptila otomita Long-horned Bee
Size: 10 mm - 2/5"
Basic species characeristics: Look for short, dense golden hairs on the bee's abdomen; a dark thorax; long antennae and a yellow clypeus on the male bee; and (with the aid of a macro lens), toothlike projections on on the tip of the bee's abdomen.
Associated plants at NBC:
Plant Family: Malvaceae
Cowpen daisy (male bee only)
Plant Family: Asteraceae
TAXONOMY OF MELISSOPTILA
Species found at National Butterfly Center: