SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO FLORIDA NATIVE BEES - ID Page #F-B5
PEBBLE BEES
Dianthidium floridense
PEBBLE BEES
Tribe Anthidiini - Genus Anthidium
THIS INFO IS FROM TEXAS WEBSITE VEBATIM
Known by the common name “pebble bees,” Dianthidium mix plant resin with materials such as soil, mud, pebbles and plant parts to construct nests. Bees of the genus Dianthidium are solitary, but sometimes their nests are conjoined or constructed nearby one another.
Dianthidium are often black with ivory or yellow markings, and their bodies and heads tend to be pitted and relatively hairless. Like leafcutters, mason bees, resin bees and other members of the family Megachilidae, Dianthidium carry pollen on scopal hairs under their abdomens. The forewings of pebble bees have two submarginal cells, and their feet have arolia.
Distinguishing traits of the genus Anthidieullum
Traits that aid in distinguishing bees of the genus Dianthidium, shown here, include the following. (1) The bee's pronotal lobes (on either side of the front of the thorax) are expanded and have thin and translucent edges. (2) The rear margin of a Dianthidium scutellum (the second thorax segment) is semicircular and convex. (3) The male Dianthidium has a prominent spine on each hind coxa (upper leg), visible when the bee is viewed from the side.
Dianthidium species are differentiated by such traits as the pale or yellow patterns on their faces, bodies and legs; their size; color; and other minute characteristics.
TAXONOMY OF DIANTHIDIUM (PEBBLE BEES)
Order: Hymenoptera
Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Dianthidium
Species shown on this page:
Dianthidium (Dianthidium) discors
A male Dianthidium discors
Coxal spine on the leg of a male Dianthidium discors
The translucent pronotal lobes of a female Dianthidium discors. Note also the semi-circular rear margin of the scutellum.
Metadata has been inserted in these photos. They were posted her on Inaturalist: https://www.inaturalist.org/observations/225604411
Associated plants:
Romerillo
(Bidense alba)
Family: Asteraceae
Melbourne Beach, FLA
(Brevard County)
June 1, 2023
Florida pebble bee
Dianthidium (Dianthidium) floridense
Family: Megachilidae
Size: 9 mm (female)
10-11 mm (male)
A female Dianthidium floridense
A female Florida pebble bee
Dorsal view of female bee
Close-up of thorax and vertex
A female Dianthidium floridense
NOTES: You probably should post a series of pictures comparing similar Dianthidium and Anthidiellum. See your notes on these bees in your research files -- you made a series of photos (from other peoples' pictures showing differences.
This 9 mm female Dianthidium floridiense (Florida pebble bee) was found gathering pollen from Bidens alba in Melbourne Beach, Florida, on June 1, 2023. This is a small black bee with dark wings, orange legs and bright orange markings on its head and body. A prominent u-shaped orange mark adorns the female's face. On males of this species, the face below the antennae is almost entirely yellow.
In the field, without the benefit of a macro lens, the easiest way to tell the female Florida pebble bee from other Florida Dianthidium and similar Anthidiellum is by the orange u-shaped facial mark.
Note that this is another predominantly yellow Florida species that differs little from the common counterpart (Dianthidium curvatum): see discussion on discover Life Page. The differences between species are size, color and “the more conspicuous second mandibular tooth of the male”.
This is more common in southeast Florida, but it has been found as far north as Jacksonville. You have good pictures of a female, but need a male. The female pictures are good quality, but they aren’t beautiful enough to do justice to this species. According to DLD, this feeds on Bidens and Sabal Palm. and calamint (Clinopodium ashei). This appears to be common at Royal Palms Park in south Florida.
When you find a male, be sure to photograph “the more conspicuous second mandibular tooth”.
ALSO: Photograph basic traits of Dianthidium, as shown in TX photos above.
LOOK FOR DIANTHIDIUM CURVATUM, for Contrast.
By contrast, Dianthidium curvatum.
Dianthidium Species of Florida
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Dianthidium." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].