SHARP-EATMAN
NATURE
PHOTOGRAPHY
Orange-tipped Digger Bee
Anthophora terminalis
1/2" (medium-sized)
Anthophora terminalis are entertaining to watch – they are unusually noisy, and they have a distinctive way of flying. They zip speedily around flowers and then stop abruptly, hovering in front of a blossom, sometimes angling their long tongues down the flower’s throat without letting their feet touch the petals. Or they buzz loudly while clinging to the flowers, and thrust their faces down so deeply into the blossoms that when the bees emerge, their heads and thoraxes are coated in pollen.
Female Anthophora terminalis carry pollen on their hind legs and practice buzz pollination -- that is, they vibrate their wing muscles, shaking pollen from the anthers of flowers. These honey-bee sized insects are exceptionally effective pollinators.
The Greek word Anthophora means “flower-bearer," or "flower-producer," but bees of this genus are commonly referred to by the more pedestrian name “digger bees”. Most digger bees construct nests in the ground by digging with their front legs and using their mandibles to loosen dirt. The Anthophora terminalis is unusual among digger bees, however, because this species constructs its nests in pithy stems and rotted wood. The bees line their nests with oils collected from plants.
Orange-tipped digger bees appear in the park during late spring and throughout the summer, but are a fairly uncommon sight. The male bees shown here were spied feeding on wild penstemon on three different sunny park trails during June of 2016 and 2017. This wildflower emerges in the park during the last weeks of spring and attracts many Anthophora terminalis during its bloom cycle.
Anthophora terminalis can be found occasionally in the park near Swan Lake in July and August, feeding on dead nettle flowers and the variety of wild impatiens known as jewel weed. The bees also have been spied in the Rockwood Hall section of the park in mid-July, feeding on the deep-throated legume known as toadflax.
In park gardens and fields, these digger bees also gravitate toward blue lobelias and the lavender-hued native bee balm known as Monarda fistulosa. The female bees shown here were discovered foraging on the native blue lobelia called lobelia siphilitica.
Anthophora terminalis play an important role in maintaining wildflower diversity, because of their ability to pollinate deep-throated and tubular blossoms inaccessible to many large bees, among them endangered wild orchids.
Identification information: Most digger bees in the United States and Canada live in western states and provinces. Only five species inhabit New York state. Because of their generally robust and "furry" appearance, digger bees are sometimes mistaken for a kind of bumble bee – some species of digger bees are even called “bumble bee mimics” because, from a moderate distance, they are nearly indistinguishable from bumble bees.
Anthophora terminalis are a striking digger bee species -- robustly-built with heads and thoraxes covered with fluffs of pale hair. Their abdomens are pitch black and traversed by precise white bands. Their legs are dark and their feet a striking reddish color. On males, the hairs of the abdomen are both dark and pale. On females, the fifth segment of the abdomen (T5) is fringed with orange hairs -- hence the common name "orange-tipped digger bee". The scopa (pollen-carrying) hairs on females' back legs are luxuriant and pale yellow.
Both male and female Anthophora terminalis have dark-veined wings, black heads, dark antennae, green eyes and unusual three-toothed mandibles. Both also possess exceptionally long tongues, which allow them to gather nectar or pollen from tubular flowers.
The male Anthophora terminalis, as shown above right, has a yellow clypeus (the face-part above the mandibles), and a mostly-yellow labrum (the face-part between the mandibles). Males of other New York digger bee species share this trait; an example is the Anthophora abrupta shown below.
TAXONOMY - Anthophora terminalis Digger Bees
Order: Hymenoptera
Family: Apidae
Subfamily: Anthophorinae
Tribe: Anthophorini (Digger Bees)
Genus: Anthophora
Subgenus: Clisodon
Species: Anthophora terminalis
A male Anthophora terminalis
A female Anthohora terminalis
Anthophora terminalis have exceptionally long tongues. Females, like the bee shown here, carry pollen on their hind legs.
A female Anthophora terminalis using its long tongue to reach into a lobelia flower, while remaining hovering in mid-air in front of the blossom
Anthophora terminalis digger bees' long tongues allow them to gather nectar and pollen from deep-throated flowers like the lobelia shown here.
Abrupt Digger Bee
Anthophora abrupta
1/2" - 3/5" (medium-sized to medium-large)
Abrupt digger bees are a rare sight in the park. So far, they have been observed only in mid-June, when they emerge to feed on wild penstamon that grows along the edges of Pocantico River Trail, close to a stream. The picture of the male Anthophora abrupta shown here is the only photograph in this guide that captures a moment in the life of a Rockefeller Park Anthophora abrupta. Appropriately, the picture was taken as the abrupt digger bee zipped by. These are boisterous, active and fast bees.
In 1929, the entomologist Phil Rau wrote of Anthophora abrupta: “They are neither timid nor aggressive, but they certainly are self-reliant…how conspicuous they are as they noisily swing their ponderous bodies to and fro on the wing, arrive home and scramble into their burrows or come tumbling out headlong and dash off into the sunny fields, with all the exuberance of boys just out of school. They have none of the shy, stealthy ways of maneuvering, whereby some of the smaller and daintier varieties of bees and wasps hold their own in a competitive world.”
Male Anthophora abrupta have additional endearing traits. In the evening, they like to climb plant stems and grass blades, grip them near the top with their mandibles, and fall asleep dangling from their jaws.
Like most other digger bees, Anthophora abrupta nest in the earth; they prefer vertical banks rather than level ground. Female Anthophora abrupta haul mud through the air with their front legs, used to moisten dirt and clay when digging nest tunnels in the ground. When Anthophora abrupta are expanding their underground lairs, they pile excavated dirt outside their holes in tall thin stacks called tumuli that look like makeshift chimneys.
Anthophora abrupta are solitary – that is, each bee builds and provisions its own nest --- but these bees are also gregarious. They prefer building their nests close by one another. “The result,” Rau wrote, is a very conspicuous village, sometimes a very crowded and busy town of these masonry turrets … At a busy season when many of these huge bees are bustling about with very audible hum and zip, the entire village with its many wonderful towers and industrious citizens form a spectacle which is in itself quite capable of overawing any but the most unemotional individual.”
Anthophora abrupta have been documented pollinating a fairly wide range of plants. They are partial to roses, inkberry, azaleas, staghorn sumac, purple milkweed, delphinium and jewelweed. In agricultural areas, these bees pollinate asparagus, tomatoes, caneberries and cranberries.
Identification information: Anthophora abrupta are round-bodied, robust bees covered with golden and black hairs. Because of these traits, they are they are sometimes mistaken for bumble bees. Bumble bees, however, never appear with the combination black head / pale thorax / black abdomen. This is the pattern characterizing Anthophora abrupta: the heads and abdomens of Anthophora abrupta bees are dark brown or black and partly-covered with black hairs; and their thoraxes are covered with pale-gold hairs. Their legs sport shaggy black hair.
Anthophora abrupta lack narrow white bands on their abdomens – a trait that helps distinguish them fairly easily from the Abrupta terminalis shown above in this guide. Anthophora abrupta are also quite hefty for New York digger bees – both males females run as large as 3/5” in length. Males can be slightly smaller than females.
As noted above in the entry on Anthophora terminalis, male digger bees found in New York tend to have yellow masks – that is, the clypei and labrums (face parts above and between the mandibles) are predominantly yellow. Masks vary from species to species. Anthophora abrupta additionally have yellow markings on their jaws and scapes (lowest antennae segments), a trait that distinguishes them from Anthophora terminalis. Although not apparent in the photograph here, Anthophora abrupta males also have a distinctive mustache of hair just above their jmandibles. Female abrupt digger bees have black faces; they also have “roman noses,” or concave profiles.
TAXONOMY - Anthophora abrupta Digger Bees
Order: Hymenoptera
Family: Apidae
Subfamily: Apinae
Tribe: Anthophorini (Digger Bees)
Genus: Anthophora
Subgenus: Melea
A male Anthophora abrupta
A male Anthophora abrupta bee, in flight, with a mane of golden hair on its thorax and a yellow facial mask
A close-up of the bee's face, showing the yellow lower segments (scapes) of the bee's antennae, and the yellow markings on its mandibles
PHOTO CREDITS: All photos and text © Copyright 2014-2017 Paula Sharp and Ross Eatman, unless otherwise noted. All rights reserved. If you wish to use any of the photographs here for educational or other purposes, please read permissions page.
REFERENCES: For a comprehensive list of references used in compiling this guide, click here:
