SHARP-EATMAN
NATURE
PHOTOGRAPHY
Calliopsis and Perdita belong to the subfamily Panurginae, within the family Andrenidae. Both genera are special to the Western Hemisphere. Within the United States, Calliopsis and Perdita are most common and most diverse in the southwest and west. Although there are more than 650 species of Perdita and at least 90 of Calliopsis, both genera are underrepresented on the east coast. Only a handful of species of each genus are found in New York. Calliopsis and Perdita are small to very small bees, often with pale or yellow markings on their faces and bodies.
Eastern Miner Bee
Calliopsis andreniformis
Size: 1/5" (small)
Various authors have noted that Calliopsis derives from the Greek word for "beautiful" (kalli) -- and that Calliopsis miner bees are, in their own special way, beautiful. Many Calliopsis have decorative yellow or cream-colored markings and brightly-colored eyes.
Miiner bees of the species Calliopsis adreniformis have striking faces: both males and females have green eyes, and males have bright yellow faces and legs as well. These singular bees are nonetheless easy to overlook, because they are so small: an adult Calliopsis andreniformis, as shown in the photo strip at right, can fit easily on a dime, with room to spare. The bees photographed here were found inadvertently, when they stumbled into the range of a macro lens while the photographer was focusing on larger pollinators.
Calliopsis andreniformis are solitary pollinators that nest in the ground. They prefer inhabiting sandy areas and the hard-packed soil of trails and well-traveled parcels of land. This trait has earned them the alternate common nae "campus bee". Calliopsis andreniformis produce one generation per year in our area.
Female eastern miner bees dig individual underground nests, usually close to flowering plants that serve as food sources. The nests are built in the form of long horizontal tunnels, lined with egg chambers, in which the mother bee stores eggs and provisions. When the miner bee eggs hatch, the young feed on the provisions and overwinter as larvae. They wait until spring to pupate into the next generation of adult bees.
Female Calliopsis andreniformis excrete an oily substance containing the chemical citral (the same chemical found in lemongrass, lemon verbena and lemons), from a special organ called the Dufour’s gland. The bees paint this substance on the walls of their egg chambers and on their nectar and pollen stores, in order to waterproof them and protect them from flooding.
According to Wilson & Carril’s The Bees in Your Backyard, Calliopsis bees have an odd mating ritual – once males couple with females, the bees remain attached as the female flies from flower to flower, until she enters her nest. This singular behavior aids in identifying the species.
Calliopsis andreniformis have a preference for plants in the pea family (Leguminosae), particularly clover and melilot -- both the male and female bees shown here were found feeding on white clover (Trifolium repens). Nevertheless, Calliopsis andreniformis is a generalist pollinator that forages on an array of plants, among them milkweed, coreopsis, catmint, cinquefoil, indigo, black-eyed Susans, fleabane, wild carrot, salvia, peonies, arrowwood, verbena, geraniums, mallow and buckwheat. Eastern miner bees are documented pollinators of a variety of crops as well, including alfalfa, apples, blueberries, strawberries, blackberries, raspberries and melons.
Eastern miner bees are widespread in the eastern and midwestern United States – Calliopsis andreniformis is found as far north as Maine, as far south as Florida, and as far west as Utah. The bees tend to appear in late spring in our area and to linger through the summer. They can be found in early June in the Rockwood Hall section of Rockefeller State Park Preserve.
The nests of eastern miner bees are preyed on by the small red-and-black cleptoparasitic cuckoo bee, Holcopasites calliopsidis.
Identification Information:
Calliopsis belong to the tribe Calliopsini; in our area, they are the sole representatives of this tribe. Entomologist Charles D. Michener noted that distinctive traits of the bee tribe Calliopsini include the following: they have robustly-shaped bodies, whatever their size; they rarely show metallic coloration; both males and females have pale markings on their faces; and the bees' forewings (as shown in the photo strip here) have two submarginal cells.
Calliopsis andreniformis (literally, "beautiful, Andrena-shaped bees") are notably small: males are barely 1/5 inch long (5-6 mm.) Females are slightly larger than males (up to 7 mm). Both males and females have predominantly dark thoraxes, adorned with two oblong stripes on the pronotal ridge (the front rim of the thorax); heads that are dark or mostly dark; and dark abdomens striped with bands of pale hairs.
Male bees, like that shown at right, have striking green eyes and predominantly yellow legs. The bottom half of the male bee’s face is bright yellow; a handful of sparse pale hairs sprout from the yellow mask. The male bee’s clypeus (the face-part above the mandibles) juts forward, and its mandibles are yellow, red and black. The male bee’s antennae are yellow below and reddish above. The scapes of the antennae (the lowest segments) are yellow.
Female eastern miner bees differ substantially in appearance from males. Like the males, females have jutting clypei and light green eyes. Females, however, lack the yellow legs and faces of the male bees. Instead, females have dark legs covered with short, fairly sparse, pale hairs. Females' faces may be entirely dark, or dark with distinctive off-white markings: usually, these markings consist of two pale blotches line the inside edges of the bottom portions of bee’s compound eyes; between them, a narrow stripe, topped by a pale trapezoid, bisects the bee's clypeus; and two small pale spots flank the trapezoid. Female bees have black mandibles with reddish areas near the middle and tips of the mandibles.
Similar species: Only one other bee of the genus Calliopsis is found in New York -- the Nebraska Calliopsis (Calliopsis nebraskensis). This bee, however, is an unusual find in New York and more common in the midwestern and prairie states. The male Calliopsis nebraskensis has black as well as yellow markings below the level of the antennae, unlike the male eastern miner bee, whose lower face is entirely yellow. The clypeus of the female Nebraska calliopsis typically lacks the central yellow stripe characteristic of the face of the female eastern miner bee. Calliopsis andreniformis also can be distinguished from the Nebrasksa calliopsis by its dietary habits -- as noted, the campus bee is a generalist pollinator that prefers legumes such as clover, while the Nebraska calliopsis forages principally on plants within the verbena family, such as vervain.
TAXONOMY:
FAMILY: Andrenidae (Mining Bees)
SUBFAMILY: Panurginae
TRIBE: Calliopsini
GENUS: Calliopsis
SPECIES: Calliopsis andreniformis
A male Calliopsis andreniformis. This bee is 1/5 inches long.
Face of a male Calliopsis andreniformis
A female Calliopsis andreniformis
Face of a female Calliopsis andreniformis
All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography
A male eastern miner bee, its mandibles clinging to the petals of a white clover blossom
The legs of the male Andreniformis calliopsis are almost entirely yellow. (Only the very topmost portions of the bee's hind femurs are black.) The scapes (lowest segments) of the male bee's antennae are also yellow.
A male resting on a dime -- this image highlights the minute size of this species.
Eight-spotted Miner Bee
aka Eight-spotted Fairy Bee
Perdita octomaculata
Size: 1/4" (small)
Bees of the genus Perdita are known by the ccommon names "miner bees" or "fairry bees". Perdita tend to build solitary nests in bare ground. Some Perdita, however, nest communally, with several females sharing common tunnels and a common nest entrance. In such arrangements, each female still lays its eggs in its own individually-built egg cells. Perdita are somewhat unusual, because instead of lining their cells or nests with waterproofing material, as many ground-nesting bees do, Perdita cover their pollen stores with a water-resistant coating. When Perdita young hatch, they eat through the protective coating. in order to devour the pollen underneath.
Because Perdita are so small, discovering their nests can be difficult. The species shown here, the eight-spotted minder bee, tends to nest in sandy or gravelly soils. According to entomologist George C. Eickwort, female eight-spotted miner bees dig as many as five nests apiece and inhabit each nest for up to nine days.
Some Perdita are generalists, but most are specialist pollinators. Perdita octomaculata is a goldenrod specialist. Nonetheless, it tends to feed on other pollen sources as well, particularly members of the aster family – including late-blooming purple asters; chicory; groundsel; knapweed; blue cornflowers; gumweed; marsh fleabane; the small white aster known as boltonia; coreopsis; and boneset. Eight-spotted miner bees also have been documented foraging on bee balm, heather and peppermint. The female bee shown here was found feeding on goldenrod in mid-September, 2017.
Local female Perdita octomaculta often can be spied lugging bright-orange balls of moistened pollen on their hind tibias, gathered from goldenrod. The pollen balls are striking because they are pellet-shaped and proportionately large burdens for such small bees. According to Eickwort, the substance the female Perdita octomaculata uses to stick the pollen balls to her scopal hairs is so strong that the pollen balls stay on the bees’ legs and maintain their round shape even while the bee is digging through sand to its nests.
Perdita tend to be most active during the hot months of summer. In our area, they are most visible in late August and early September, a period that coincides with the bloom of goldenrod, boneset and various species of white aster. The male bee shown in the photo strip at right, however, appeared in the park in late June.
Perdita have been observed only rarely in the woodland / wetland habitat of Rockefeller State Park Preserve. This habitat's soil tends to be rich and full of organic materials, rather than sandy. (Perdita have proven to be more common nine miles to the north of the preserve, in a scruffy and sandy railroad access road, nestled between a swamp and a town dump.)
A female Perdita octomaculata.
A female Perdita octomaculata
Identification Information:
Both male and female eight-spotted miner bees are
very small – females run slightly longer than 1/4” (7 mm), and males slightly smaller than 1/4” (6 mm). To the naked eye, Perdita octomaculata appear to be tiny black wasps with pale stripes.
Observed more minutely, Perdita octomaculata have dark heads with green eyes; dark faces and thoraxes with pale-yellow markings; and abdomens decorated with pale or bright yellow spots. Both males and females have wings that are a transparent light brown with darker brown veins. The bodies of both males and females are relatively hairless, a fact that makes these bees appear all the more wasplike.
Female Perdita octomaculata are best identified by the pale marks on their abdomens. Females have eight well-defined yellow “spots” situated in pairs on either side of the first through fourth segments of their abdomens (T-1 to T-4) . According to entomologist Theodore B. Mitchell’s Bees of the Eastern United States, the fifth segment of the female's abdomen (T5) is entirely black.
The spots on male Perdita octomaculata are often a brighter yellow than is typical of the females’ (which tend to be pale yellow). Males usually have ten spots, arranged in pairs on either side of the first through fifth segments of their abdomens (T-1 to T-5).
The thoraxes of females have pale-yellow markings on the pronotum (the front end of the thorax) and on each pronotal lobe (the roughly-circular plates in front of and slightly below the wings). The pronotum of the male bee can be entirely dark, or dark with pale-yellow markings (but not all-yellow). Male eight-spotted miner bees also have yellow markings on their predominantly black legs.
As noted, these bees' faces are also decorated with yellow markings. As shown in the photos here, the facial markings of females are distinctive: the female bee’s clypeus (the part above the mandibles) is usually mostly yellow, with two dark curved vertical stripes; additional yellow areas flank the clypeus on either side. The scapes (lowest segments) of the female's antennae are entirely dark. The mandibles are yellow with rust-colored tips.
Male Perdita octomaculata have varied facial markings that differ from those of typical females. The male 's clypeus is yellow, but lacks the two dark stripes typical of females. Male bees’ antennal scapes and the area above the male bee’s clypeus can be dark, pale or bright yellow. The hind tibias of male bees are partly yellow.
Female eight-spotted fairy bees have short scopal hairs because they use moisture to stick pollen loads to their hind tibias. Under magnification, as shown in the photos here, the scopal hairs on the female bees’ legs are singular looking – they stick out a little like cactus prickers, nearly perpendicular to the leg. Under more intense magnification, the individual hairs appear “unbranched” – that is, with a simple structure, without smaller hairs branching from the sides of each hair. (Branched hairs are a trait common in most other bees, because this allows for efficient pollen-collection.)
TAXONOMY:
FAMILY: Andrenidae (Mining Bees)
SUBFAMILY: Panurginae
TRIBE: Panurgini
SUBTRIBE: Perditina
GENUS: Perdita
SUBGENUS: Perdita
SPECIES: Perdita octomaculata
Face of a female Perdita octomaculata
All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography
A female eight-spotted miner bee (also known as the eight-spotted fairy bee)
Dorsal view of female
Female eight-spotted miner bees have dark bodies adorned with pale-yellow spots on the thorax, abdomen and legs.
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:
