Tribe Caupolicanini - Genus Ptiloglossa
Ptiloglossa are robustly-built, hairy bees with enlarged ocelli adapted to navigating low-light conditions. The bees avoid periods of intense sunlight and fly during early morning or dusk. Their tongues are forked and feathery – Ptiloglossa is Greek for “feather-tongue”.
Feather-tongued bees tend to be loud and large fliers, usually measuring between 15-20 mm (3/5-4/5 in). They are buzz pollinators that often target nightshade-family plants (Solanaceae). Ptiloglossa also frequent other plants – among them passionflowers and pea-family flora such as cassia, indigo and sweetclover.
The Mexican feather-tongued bee, shown here, ranges from southern Texas to northern South America. Within the United States, this species occurs almost exclusively in the Lower Rio Grande Valley. Documented occurences of Ptiloglossa mexicana in the Valley are relatively uncommon. In the last decade, most have occurred in Hidalgo County.
Sightings of Ptiloglossa in the Valley are uncommon in part because of the bees’ unusual flight schedule. Feather-tongued bees often emerge before dawn to visit flowers. On hot days, they may retire by 9:00 a.m. They sometimes reappear in late evening: they can be found foraging on flowers just as the sun is beginning to set.
TAXONOMY OF FEATHER-TONGUED BEES
Species shown on this page:
Heriades (Neotrypetes) variolosa
(Mexican feather-tongued bee)
A female Ptiloglossa mexicana investigating a passionflower
A female Ptiloglossa mexicana: note the luminous pink ocellus
(the small eye above the large compound eye
Ptiloglossa Species of the National Butterfly Center & Lower Rio Grande Valley
Mexican feather-tongued bee
Size: 19 mm (female)
15 mm (male)
Associated plant at NBC:
(Passiflora foetida var. gossypiifolia)
When and where found:
May & July 2021
Garden of Master Gardener William Rich
McAllen Texas (Hidalgo County)
A female Ptiloglossa mexicana
Dorsal view of female Ptiloglossa mexicana
Close-up of female Ptiloglossa mexicana. The bee’s face has a large malar space (the gap between the mandible base and the compound eye) – it is at least one-third the length of the compound eye.
Abdomen of a a female Ptiloglossa mexicana: the hairs of the abdomen catch the light and, to the naked eye, they look shimmery and chatoyant. On both females and males of this species, the first three abdominal segments (T1-T3) are covered with golden hairs. On females, T4 has some dark hairs, and T5-T6 are covered with dark hairs.
Rear view of the female bee's abdomen & pygidial plate
A female Mexican feather-tongued bee (Ptiloglossa mexicana)
Physical Characteristics of Ptiloglossa mexicana
The Mexican feather-tongued bee is a hefty, furry-looking, gold bee with a dark abdomen girded by golden bands. Its legs are reddish gold, its tegulae are honey-yellow and partly covered with golden hairs, and its wings auburn with dark veins. Hairs on the Mexican feather-tongued bee’s thorax and abdomen have a shimmery, chatoyant quality, with silky bluish-green reflections, so that under strong morning or evening light the bee appears radiant. The bee’s compound eyes are large and black. The female bee’s enlarged ocelli are pink and appear luminous under direct light.
Three Ptiloglossa species are known to the Valley: Ptiloglossa arizonensis, Ptilogossa haploboda, and Ptiloglossa mexicana. Feather-tongued bee species are separated in part by subtleties in the coloring of hairs on the vertex, thorax and abdomen; by characteristics of the mandibles; and by the coloring of the labrum (the face part between the mandibles) and clypeus (the face-part above the labrum).
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Ptiloglossa." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].