SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
CUCKOO-LEAFCUTTER BEES
Coelioxys
Aztec cuckoo leafcutter
Coelioxys (Leuraspidia) aztecus
Family: Megachilidae
Size: 10 mm (female)
7 mm (male)
Associated plants at NBC:
Rio Grande abutilon
(Abutilon hypoleucum)
Plant Family: Malvaceae
romerillo
(BIdens alba)
Plant Family: Asteraceae
When Seen:
Oct. - Nov., 2018-2022
A female Aztec cuckoo leafcutter bee
Dorsal view of a female Aztec cuckoo leafcutter bee
A female Aztec cuckoo leafcutter bee (Coelioxys aztecus)
A male Aztec cuckoo leafcutter bee Coelioxys azteca
CUCKOO LEAFCUTTER BEES
Genus Coelioxys
Coelioxys are cuckoo bees that prey on leafcutter bees by invading their nests and depositing eggs in them. When the cuckoo's young hatch, they destory the host's eggs or larvae and then devour the stores of nectar and pollen left by the mother leafcutter for her offspring.
Coelioxys are members of the same tribe as leafcutter bees -- Megachilini -- and somewhat resemble them. Cuckoo leafcutters, however, lack pollen-collecting scopal hairs, because they do not collect pollen. They acquire pollen for their offspring by robbing it from their hosts. (Cuckoo bees, nonetheless, do drink nectar from flowers.)
The abdomen of the female cuckoo leafcutter terminates in a sharp spade-like tip -- the Greek Coelioxys means "sharp belly". This feature allows the cuckoos to break through the brood-cell walls that leafcutters construct with leaves, petals and other materials. Male cuckoo leafcutters have abdomens armed with multi-pronged tips.
Both male and female cuckoo leafcutters have a habit of grasping leaves and stems with their jaws. In the Lower Rio Grande Valley, Coelioxys often can be found sleeping in groups on vegetation, hanging by their mandibles.
General Identification Information:
Cuckoo leafcutter species are told apart by such traits as leg color; the patterns of pale hair bands and grooves on the abdomen; the form of the abdominal tip; and the shape of the rear edge of the cuckoo's scutellum (second segment of the thorax). Coelioxys cuckoos have foveae (depressions) on the sides of their second or third abdominal segments (T2 and T3). Noting the size, shape and presence or absence of such foveae often aids in species identification.
Coelioxys frequently have black bodies and legs. Some species found as far north as New York have red legs and tegulae (the plates where the wings join the bee's body). Neotropical species, such as those found in the Lower Rio Grande Valley and in Mexico, tend to be more colorful. In addition to having red legs and tegulae, they may have striking red patterns on their abdomens and thoraxes.
Cuckoo leafcutter bees of the Lower Rio Grande Valley
Shown here are six Coelioxys species representing six different subgenera. All four are striking bees with extensive red coloration.
Four Coelioxys species have been discovered at the National Butterfly Center: the Aztec cuckoo leafcutter (Coelioxys aztecus); Slosson's sand-dwelling cuckoo leafcutter (Coelioxys slossoni arenicola); the Texas cuckoo leafcutter (Coelioxys texanus) and the scaly cuckoo leafcutter (Coelioxys editus). A fifth species, the Totonac cuckoo leafcutter (Coelioxys totonacus); appeared at Quinta Mazatlan of McAllen, Texas (Hidalgo Co.) in 2022. A sixth speciess, the Zapotec cuckoo leafcutter (Coelioxys zapotecus),was recorded at Falcon State Park (Starr co.) in April 2023.
Coelioxys totonacus and Coelioxys zapotecus had not been found previously within the United States. Coelioxys aztecus is rarely seen in the United States and found principally in Mexico. Slosson's sand-dwelling cuckoo leafcutter is native to Mexico and border areas of the United States. Coelioxys edita is a more widespread species, found throughout the western United States, as far east as Illinois, Arkansas and Florida, and as far north as Alberta.
A female Coelioxys zapotecus Coelioxys zapoteca
The red underside of a female Coelioxys slossoni arenicola
TRAITS OF COELIOXYS
In North America, cuckoo leafcutter bees are usually black, or black with red legs. Their eyes are often green or light brown.
In the Lower Rio Grande Valley, several cuckoo leafcutter bee species have extensive red coloration. Parts or all of the bees' abdomens may be red.
The typical female Coelioxys has a spade-shaped tip on its abdomen.
TAXONOMY OF CUCKOO LEAFCUTTER BEES
Order: Hymenoptera
Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile
Species shown on this page:
Coelioxys (Glyptocoelioxys) totonacus
(Totonac cuckoo leafcutter)
Coelioxys (Leuraspidia) aztecus
(Aztec cuckoo leafcutter)
Coelioxys (Neocoelioxys) slossoni arenicola
(Slosson's sand-dwelling cuckoo leafcutter)
Coelioxys (Rhinocoelioxys) zapotecus
(Zapotec cuckoo leafcutter)
Coelioxys (Synocoelioxys) texanus
(Texas cuckoo leafcutter)
Coelioxys (Xerocoelioxys) editus
(Scaly cuckoo leafcutter)
Male Coelioxys totonacus
Coelioxys Species of the Lower Rio Grande Valley
Associated plants:
crucita (female)
(Chromolaena odorata)
resinbush (male)
(Chromolaena odorata)
Plant family: Asteraceae
When and where seen:
November 2021
Quinta Mazatlan
McAllen, TX (Hidalgo Co.)
April 25, 2023
Falcon State Park
Roma, TX (Starr Co.)
Totonac cuckoo leafcutter
Coelioxys (Glyptocoelioxys) totonacus
Family: Megachilidae
Size: 11 mm (female),
8.5 mm (male)
A female Coelioxys totonacus on crucita
View of thorax: note the three spines on the back of the bee's scutellum, defining traits of its subgenus Glyptocoelioxys.
Alternate view of spines on scutellum
The following parts of this male Coelioxys are red: the front and middle legs; the upper hind legs; the tegulae, part of each lateral spine of the axillae; most of T1 (but not its front face); and most of the sternum.
Dorsal view of vertex and thorax
Close-up of thorax, showing a median point on the rear scutellum
A female Totonac cuckoo leafcutter bee (Coelioxys totonacus)
A female Totonac cuckoo leafcutter bee (Coelioxys totonaca)
A male Totonac cuckoo leafcutter bee
Coelioxys (Glyptocoelioxys) totonacus can be recognized by the three prominent spines protruding from the back of its scutellum. The female Totonac cuckoo leafcutter shown here is the first recorded example of this species within the United States. It appeared at Quinta Mazatlán (Hidalgo Co.) in early November 2021. The male appeared at Falcon State Park (Starr Co.) in mid-April 2023.
A male Coelioxys aztecus
Lateral view of male bee
Associated plants:
Resinbush
(Viguiera stenoloba)
Plant family: Asteraceae
When and where seen:
April 21, 2023
Falcon State Park
(Starr Co.)
Zapotec cuckoo leafcutter bee
Coelioxys (Rhinocoelioxys) zapotecus
Family: Megachildae
Size: 10.5 mm (male)
A male Coelioxys zapotecus Coelioxys zapoteca
A male zapotec cuckoo leafcutter
Dorsal view of bee: this Coelioxys has red legs, and red on on its thorax, tegulae, upper abdomen, sternum, antennal scapes and manidbles. Its wings are dark brown.
The coarsely-pitted scutum and scutellum are partly red. Note the unpitted area of the scutellum that loosely forms a median ridge.
Coelioxys (Rhinocoelioxys) zapotecus is a subtropical bee, and its occurrence at Falcon State Park of Starr County marks a significant range extension for this species. Previously, its northern range was thought to be the Mexican state of San Luis Potosi. As shown in the accompanying photo strip, male Zapotec cuckoo leafcutters can be recognized by a lossely-defined median ridge on the scutellum, and by a U-shaped notch on the hind rim of S6. Females have a distinctive bi-lobed structure on the clypeus.
A description of this species can be found in: Filho, Léo Correia Da Rocha, and Packer, Laurence (2015). Revision of the neotropical subgenera Coelioxys (Platycoelioxys) Mitchell and C. (Rhinocoelioxys) Mitchell (Hymenoptera; Megachilidae) with the description of one new species. Zootaxa 3941 (2): 151-203.
Associated flora at NBC:
Resinbush
(Viguiera stenoloba)
Seaside goldenrod
(Solidago sempervirens)
Family: Asteraceae
When seen: October 2019
Texas cuckoo leafcutter bee
Coelioxys (Synocoelioxys) texanus
Family: Megachildae
Size: 11 mm (male)
14 mm (female)
A female Coelioxys texanus
Lateral view of female Coelioxys texanus
Face of female bee: the antennal scapes and pedicels are red. This is an unusual trait for Coelioxys in Valley, and aids greatly in identifying this species.
A male Coelioxys texanus
Alternate view of male bee
The scapes and pedicels of the male bee's antennae are red, like the female's.
A female Texas cuckoo leafcutter (Coelioxys texanus) Coelioxys texana
A male Texas cuckoo leafcutter: note the red antennal scapes
A male Texas cuckoo leafcutter
Food plant at NBC:
Carpet vervain
(Verbena bracteata)
Whitebrush
(Alyosia gratissima)
Plant family: Verbenaceae
Resinbush
(Viguiera stenoloba)
Plant family: Asteraceae
When seen:
September 2018,
April - July, 2019
Slosson's sand-dwelling
cuckoo leafcutter
Coelioxys (Neocoelioxys)
slossoni arenicola
Family: Megachilidae
Size: 15 mm (female)
A female Coelioxys slossoni arenicola
The red underside (sternum) of the female of this species is distinctive -- few cuckoo leafcutter species of the United States have such extensive red coloration on their abdomens.
A male Coelioxys slossoni arenicola
Dorsal view of male bee
A female Coelioxys slossoni arenicola
A male Coelioxys slossoni arenicola
Scaly cuckoo leafcutter
Coelioxys (Xerocoelioxys) editus
Family: Megachilidae
Size: 12 mm (female); 10 mm (male)
Food plant at NBC:
Common Sunflower
(Helianthus annuus)
Plant Family: Asteraceae
When seen:
September 2018
A female Coelioxys editus (Coelioxys edita)
A female Coelioxys editus
The first three segments of the sternum (S1-S3) of this female Coelioxys editus are red. Its legs are also red.
A male Coelioxys editus: within this species, abdomen and leg color varies. Males' legs and abdominal parts range from rust-red to black.
Dorsal view of the male bee
A male Coelioxys editus
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Coelioxys." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].