Eucera fasciatella
Size: 10.5 mm (male)
Eucera fasciatella
Size: 10.5 mm (male)
Eucera fasciatella
Size: 10.5 mm (male)
Identification Page #17
Protoandrena & Andrena
Identification Page #17
Protoandrena & Andrena
Identification Page #17
Protoandrena & Andrena
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
SHARP-EATMAN
NATURE
PHOTOGRAPHY
CUCKOO LEAFCUTTER BEES
Genus Coelioxys
Coelioxys cuckoo bees prey on leafcutter bees by invading their nests and depositing eggs in them. When the cuckoo's young hatch, they eat the host's eggs and then devour the stores of nectar and pollen left by the mother leafcutter for her offspring.
Coelioxys cuckoo bees 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 don't have to, since they acquire it by robbing it from their hosts. (Cuckoos, nonetheless, do drink nectar from flowers.)
In addition, as shown at right, 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.
Cuckoo leafcutters sometimes can be seen lifting their pointed, conical abdomens, in a scorpion-like manner. Both males and females also have a habit of grasping leaves and stems with their jaws. Male cuckoo leafcutters can be found sleeping on vegetation, hanging upside-up or upside down by their mandibles.
According to entomologist Charles D. Michener, members of the genus Coelioxys share the distinctive trait of having hairs on their eyes. In addition, the wings of the cuckoo leafcutter bee have only two submarginal cells, and the back rim of the bee's scutellum (at the hind end of the thorax) is often toothed. These traits are shown in the photo strip below right.
General Identification Information:
Cuckoo leafcutter species appear very similar to the casual observer, and species identification is often best left to an expert. 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 bottom edge of the cuckoo's thorax (the scutellum). 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 cuckoo bees frequently have black bodies and legs. Some species found as far north as New York have red legs and tegulae (the nodes 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.
Coelioxys bees of the National Butterfly Center:
During the autumn of 2018 and 2019, four Coelioxys species were discovered at the National Butterfly Center: the Aztec cuckoo leafcutter (Coelioxys azteca); Slosson's sand-dwelling cuckoo leafcutter (Coelioxys slossoni arenicola); the Texas cuckoo leafcutter (Coelioxys texanus) and the scaly cuckoo leafcutter (Coelioxys edita). All four of these are striking bees with extensive red coloration on their abdomens and other body parts.
The Aztec cuckoo leafcutter is rarely seen in the United States. It is a neotropical species that has been documented 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.
All of these species are shown in detail in the entries below.
A female Coelioxys slossoni arenicola cuckoo leafcutter bee
The red underside of a female Slosson's sand-dwelling cuckoo leafcutter bee
The typical female Coelioxys has a spade-shaped tip on its abdomen.
Male Coelioxys cuckoos often have multi-pronged tips on their abdomens.
In North America, cuckoo leafcutter bees are usually black, or black with red legs. Their eyes are often green or light brown.
Traits of Coelioyxs cuckoo bees
TAXONOMY OF CUCKOO LEAFCUTTER BEES
Order: Hymenoptera
Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile
Species shown on this page:
Coelioxys (Leuraspidia) azteca (Aztec cuckoo leafcutter) a
Coelioxys (Neocoelioxys) slossoni arenicola
(Slosson's sand-dwelling cuckoo leafcutter)
Coelioxys (Synocoelioxys) texanus
(Texas cuckoo leafcutter)
Coelioxys (Xerocoelioxys) edita
(Scaly cuckoo leafcutter)
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
CUCKOO-LEAFCUTTER BEES
Coelioxys
Associated plants at NBC:
Rio Grande Abutilon
(Abutilon hypoleucum)
Plant Family: Malvaceae
Spanish needles
(BIdens alba)
Plant Family: Asteraceae
When Seen:
November 2018, October 2019
Aztec Cuckoo Leafcutter Bee
Coelioxys (Leuraspidia) azteca
Family: Megachilidae
Size: 10 mm (female)
7 mm (male)
A female Aztec cuckoo leafcutter bee
Dorsal view of a female Aztec cuckoo leafcutter bee
Male Coelioxys
A female Aztec cuckoo leafcutter bee
A male Aztec cuckoo leafcutter bee
Slosson's Sand-dwelling
Cuckoo Leafcutter Bee
Coelioxys (Neocoelioxys)
slossoni arenicola
Family: Megachilidae
Size: 15 mm (female)
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, June, July 2019
A female Slosson's cuckoo leafcutter bee
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 Slosson's cuckoo leafcutter
Dorsal view of male bee
A female Coelioxys slossoni arenicola cuckoo leafcutter bee
A male Coelioxys slossoni arenicola cuckoo leafcutter bee
Scaly Cuckoo Leafcutter Bee
Coelioxys (Xerocoelioxys) edita
Family: Megachilidae
Size: 12 mm (female); 10 mm (male)
Food plant at NBC:
Common Sunflower
(Helianthus annuus)
Plant Family: Asteraceae
When seen:
September 2018
Detailed Photographs:
A female Coelioxys edita cuckoo bee. Within the species Coelioxys edita, coloration varies among individual bees. The color of females' abdominal parts and legs may range from rust-red to black.
The the top segment of this female bee's abdomen (T1) is red.
A male Coelioxys edita cuckoo leafcutter bee. 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 female Coelioxys edita cuckoo leafcutter bee
A male Coelioxys edita cuckoo leafcutter bee
Texas Cuckoo Leafcutter Bee
Coelioxys (Synocoelioxys) texanus
Family: Megachildae
Size: 11 mm (male)
14 mm (female)
Associated plant at NBC:
Resinbush
(Viguiera stenoloba)
Seaside goldenrod
(Solidago sempervirens)
Family: Asteraceae
When seen: October 2019
A male Texas cuckoo leafcutter bee
Male bee
Close-up of head and vertex
A male Texas cuckoo leafcutter bee
Female Coelioxys
Dorsal view of head & thorax
A female Texas cuckoo leafcutter bee