SHARP-EATMAN
NATURE
PHOTOGRAPHY
CACTUS BEES OF THE LRGV
Quick Visual Guide to 20 LRGV Bee Species That Visit Cactus
A species list appears at the bottom of this page.
List of Species
Agapostemon tyleri (Tyler's Agapostemon): This bright green, striped sweat bee is rare in the Valley. It is a generalist pollinator. This species was found visiting candy barrel cactus (Ferocactus wislizeni) at Campos Viejos Ranch in Starr County.
Andrena miserabilis (miserable mining bee): This bee appears in early spring at the Mission Hike & Bike in large numbers: females construct ground nests in hard-packed trails running through the site's extensive groves of prickly pear (Opuntia engelmannii var. lindheimeri) . I did not find the bees on the cactus, but I've never found this species anywhere else in the Valley except at this one location -- so I'm wondering whether the location is incidental or evidence that the species visits cactus. It could be that the sandy soil liked by the cactus is also attractive to the mining bees.
Anthophorula compactula (compact anthophorula): This is a common spring visitor in the Valley to both prickly pear (Opuntia engelmannii var. lindheimeri) and twisted rib cactus (Thelocactus setispinus). Although broadly polylectic, this species emerges in the Valley during the spring cactus bloom and is most likely to be found on small, low-growing cacti. Males sometimes sleep inside Argemone sanguinea. This is a small bee - smaller than a typical honey bee.
Ashmeadiella cactorum (cactus ashmeadiella): This generalist species appears on prickly pear (Opuntia engelmannii var. lindheimeri). Ashmeadiella cactorum is smaller than Ashmeadiella maxima, and less densely haired. The female Ashmeadiella cactorum also has sparse orange hairs on the outer mandibles. All male Ashmeadiella have 4 spines/prongs on the tips of their abdomens -- this feature is visible to the naked eye. On first glance, Ashmeadiella look a little like resin bees, and are sometimes confused with them.
Ashmeadiella maximum (cactus anthidiellum): This generalist species appears on prickly pear (Opuntia engelmannii var. lindheimeri).
Augochlora azteca (Aztec sweat bee): This is a brilliant blue-green bee that visits prickly pear in the Valley (Opuntia engelmannii var. lindheimeri). I've seen both males and females on prickly pear, but I'm uncertain whether females gather pollen from the cacti or just visit them for nectar. This species might be confused with the Ceratina cobaltina noted below, but the latter is much smaller and less likely to be found on prickly pear.
Ceratina cobaltina (cobalt small carpenter bee: This is an adventive generalist species sometimes found on prickly pear. It is briliant blue-green and about the size of a large ant.
Ceratina texana (Texas small carpenter bee: This generalist pollinator occasionally appears on pitaya (Echinocereus enneacanthus). It also visits golden prickly poppy (Argemone aenea) . The Texas small carpenter bee is a dark metallic green. It is ant-sized and generally smaller than the cobalt small carpenter bee.
Coelioxys texanus (Texas cuckoo leafcutter bee): This cuckoo bees lays eggs in the nests of female Megachile policaris (thumbed leafcutters). Cuckoo bees do not collect pollen -- they merely drink nectar from plants. This species has been recorded nectaring on prickly pear.
Diadasida diminuta (globe mallow bee): This chimney bee is a mallow speciialist, but it sometimes visits prickly pear. This is a smallish beige bee that fits easily on the head of a dime.
Diadasida rinconis (Rincon chimney bee): This bee is one of the principal cactus-visitors in the Valley. Many Diadasia, inlcuding this species, are cactus specialists. This bee is larger than Diadasia diminuta (the globe mallow bee) -- about the size of a small bumble bee.
Dianthidium discors (discordant pebble bee): This species was found visiting candy barrel cactus (Ferocactus wislizeni) at Campos Viejos Ranch in Starr County. Its yellow jagged-striped banding makes it easy to identify. Females dig into holes in cacti and flash their abdomens at males. They mate directly on the cacti.
Lithurgopsis littoralis (littoral cactus woodborer bee): This is the dominant Lithurgopsis species of the Lower Rio Grande Valley, and it is the most common cactus polliinator in the Valley. It looks like a hefty leafcutter with unusually long legs. Males overnight in prickly poppies.
Megachile montivaga (silver-tailed petal-cutter): This is an uncommon leafcutter bee species. It is a generalist pollinator that occasionally visits prickly pear.
Megachile policaris (thumbed leafcutter): This is also a generalist pollinator that occasionally visits prickly pear. It is the most likely leafcutter species to encounter on prickly pear in the Valley. As noted above, it is a host to Coelioxys texanum (the Texas cuckoo leafcutter), which also sometimes visits prickly pear.
Melissodes opuntiellus (little prickly pear longhorn bee): This generalist bee is a common prickly pear visitor in the Valley. Males sometimes sleep inside Argemone sanguinea. This species is small for a longhorn bee -- it is about honey bee size.
Melissodes tepaneca (Tepancec longhorn bee): This bee is a broad generalist pollinator that occasionally visits prickly pear in the Valley. It is slightly larger than a honey bee.
Osmia subfasciata (faintly-banded mason bee): This is a blue-green metallic bee, about half the size of a honey bee. It coes not pollinate cacti, but it does visit prickly pear in the spring for nest-building materials. The females chew off the new buds of prickly pear pads and carry them to their nest sites. This bee is easy to identify to subgenus, but species identification may be tricky, because there are at least three small blue-green metallic mason bees that emerge in spring in the Valley.
Svastra duplocincta (barrel cactus longhorn): Svastra duplocincta is a cactus polinator speciaiist. It appeared in 2022 at Campos Viejos Ranch in Starr County, feeding on candy barrel cactus (Ferocactus wislizeni).
Triepeolus vernus (spring triepeolus cuckoo bee): This is an uncommon cuckoo bee that deposits eggs in the ground nests of longhorn bees -- its exact species host is unknown. I've found it lurking around the nests of Melissodes opuntiellus and Anthophorula compactula, and also visiting twisted-rib cactus. I'd love to find out what its host is.
Striped & Banded Non-Metallic Bees
(click to enlarge)

Andrena miserabiis (miserable mining bee) - male

Andrena miserabiis (miserable mining bee) - female

Andrena miserabiis (miserable mining bee) - face of male

Ashmeadiella maxima (greater ashmeadiella) - male

Ashmeadiella maxima (greater ashmeadiella) - male - all male Ashmeadiella have abdomens with 4-pronged tips

Anthidiellum (cactus anthidiellum) - female - Ashmeadiella cactorum is smaller than Ashmeadiella maxima, and less densely haired. The female Ashmeadiella cactorum also has sparse orange hairs on the outer mandibles.

Anthophorula compactula (compact anthophorula) - female

Anthophorula compactula (compact anthophorula) - male

Anthophorula compactula (compact anthophorula) - male - note striped antennae

Coelioxys texanus (Texas cuckoo leafcutter) - male

Dianthidium discors (Discordant pebble bee) - female - a visitor of candy barrel cactus

Dianthidium discors (Discordant pebble bee) -female

Dianthidium discors (Discordant pebble bee) -male

Dianthidium discors (Discordant pebble bee) -distinctive jagged stripes on bee's abdomen

Dianthidium discors (Discordant pebble bee) -- female - females dig headfirst into cacti and flash their yellow-spotted abdomens at males during mating

Diadasia diminuta (globemallow bee) - female

Diadasia diminuta (globemallow bee) - male. This is a small chimney bee -- it is shown here on a dime

Diadasia diminuta (globemallow bee) - male - white hairs cover the male's lower face

Diadasia rinconis (Rincon chimney bee) - female - females have striped abdomens and beige thorax hairs

Diadasia rinconis (Rincon chimney bee) - male - males are covered entirely with beige hairs

Diadasia rinconis (Rincon chimney bee) - males - males often sleep in prickly poppies

Diadasia rinconis (Rincon chimney bee) - males - males pile on top of each other and form "scrums" like these when mating

Lithurgopsis littoralis (littoral cactus woodborer bee) - female

Lithurgopsis littoralis (littoral cactus woodborer bee) - male

Lithurgopsis littoralis (littoral cactus woodborer bee) - this is the typical view of the bee, with its head immersed in a cactus flower

Megachile montivaga (silver-tailed petal-cutter) - female

Megachile policaris (thumbed leafcutter) - female

Megachile policaris (thumbed leafcutter) - male

Melissodes opuntiellus (little prickly pear longhorn bee) - female

Melissodes opuntiellus (little prickly pear longhorn bee) - male

Melisoodes tepaneca (tepanec longhorn bee) - female

Melisoodes tepaneca (tepanec longhorn bee) - male

Svastra duplocincta (barrel cactus longhorn) - female

Svastra duplocincta (barrel cactus longhorn) - easily identified by unique pattern of broad white abdominal bands

Triepeolus vernus (spring Triepeolus cuckoo bee) - female

Triepeolus vernus (spring Triepeolus cuckoo bee) - female
Metallic Green or Blue-green Bees
(click to enlarge)

Agapostemon tyleri (Tyler's agapostemon) - female - note white stripes

Agapostemon tyleri (Tyler's agapostemon) - male - note yellow stripes and yellow legs

Augochlora azteca (Aztec sweat bee) - female

Augochlora azteca (Aztec sweat bee) - face of female

Ceratina cobaltina (cobalt small carpenter bee) - female - both males and females are brilliant blue-green. This adventive species is smaller and less common on cactus than Augochlora azteca.

Ceratina cobaltina (cobalt small carpenter bee) - male - males are smaller than females and have pale facial markings

Ceratina texana (Texas small carpenter bee) - male

Ceratina texana (Texas small carpenter bee) - face of male bee

Osmia subfasciata (faintly-banded mason bee) - female

Osmia subfasciata (faintly-banded mason bee) - male

Osmia subfasciata (faintly-banded mason bee) - females chew leaf buds off of prickly pear pads to use for nesting materials