Chunky Bees that Carry Pollen Under their Abdomens: A Guide to their identification in Eastern North America

Acknowledgements This presentation has been put together by a consortium of North American bee biologists This presentation has developed over many years and the original web picture acknowledgements were lost, if you see one of your pictures let us know and we will add your picture credit Correspondence can be sent to Sam Droege at sdroege@usgs.gov

This presentation has been put together by a consortium of North American bee biologists

This presentation has developed over many years and the original web picture acknowledgements were lost, if you see one of your pictures let us know and we will add your picture credit

Correspondence can be sent to Sam Droege at sdroege@usgs.gov

Format Each Genus has an information page followed by a page of illustrations and a map of the distribution of Eastern North American species; western populations of Eastern species are shown, but the Western species are not mapped. The number of Eastern species are listed at the top of the page

Each Genus has an information page followed by a page of illustrations and a map of the distribution of Eastern North American species; western populations of Eastern species are shown, but the Western species are not mapped.

The number of Eastern species are listed at the top of the page

Anthidiellum – 2 species Anthidium - 4 Dianthidium - 3 Paranthidium - 1 Stelis - 12 Trachusa - 5 Hoplitis - 8 Osmia - 28 Ashmeadiella - 2 Chelostoma - 3 Heriades - 3 Coelioxys - 24 Lithurgus - 3 Megachile - 40

Anthidiellum – 2 species

Anthidium - 4

Dianthidium - 3

Paranthidium - 1

Stelis - 12

Trachusa - 5

Hoplitis - 8

Osmia - 28

Ashmeadiella - 2

Chelostoma - 3

Heriades - 3

Coelioxys - 24

Lithurgus - 3

Megachile - 40

Anthidiellum Quite small, less than half the size of a honeybee Fast flying, likes legumes, dry fields Front of the mesepisternum (side facing the head) divided from the outward facing side by a sharp edge or carina Unique in that the scutellum projects over the metanotum and propodeum as a THIN squared- off shelf, other species project a small amount but not as much and the edge is rounded over Unique in that the sub-antennal sutures bend outwards Similar Genera: Anthidium, Dianthidium, Paranthidium, Stelis, Trachusa

Quite small, less than half the size of a honeybee

Fast flying, likes legumes, dry fields

Front of the mesepisternum (side facing the head) divided from the outward facing side by a sharp edge or carina

Unique in that the scutellum projects over the metanotum and propodeum as a THIN squared- off shelf, other species project a small amount but not as much and the edge is rounded over

Unique in that the sub-antennal sutures bend outwards

Similar Genera: Anthidium, Dianthidium, Paranthidium, Stelis, Trachusa

2 Species, small, fast, likes legumes and dry sites

Anthidium 2 common introduced species, 2 rare native species, most about the size of a honeybee or slightly smaller Unique among genera listed below in that it has no pad or arolium between the tarsal claws at the ends of the legs Female unique in that it has 5 or more teeth on the mandible Similar Genera: Anthidiellum, Dianthidium, Stelis, Trachusa, Paranthidium

2 common introduced species, 2 rare native species, most about the size of a honeybee or slightly smaller

Unique among genera listed below in that it has no pad or arolium between the tarsal claws at the ends of the legs

Female unique in that it has 5 or more teeth on the mandible

Similar Genera: Anthidiellum, Dianthidium, Stelis, Trachusa, Paranthidium

Some common introduced species 4 Species

Dianthidium A bit smaller than a honey bee, uncommon to rare Has a small hollowed out area or fovea behind the spiracle on the rear face of the propodeum about the size of the spiracle Front of the mesepisternum (side facing the head) divided from the outward facing side by a sharp edge or carina Similar Genera: Anthidium, Paranthidium, Stelis, Anthidiellum, Trachusa

A bit smaller than a honey bee, uncommon to rare

Has a small hollowed out area or fovea behind the spiracle on the rear face of the propodeum about the size of the spiracle

Front of the mesepisternum (side facing the head) divided from the outward facing side by a sharp edge or carina

Similar Genera: Anthidium, Paranthidium, Stelis, Anthidiellum, Trachusa

Uncommon to rare 3 Species

Paranthidium jugatorium Rare, but known to occur abundantly in at least one arboretum Front of the mesepisternum (side facing the the head) NOT divided from the outer facing side by a sharp edge or carina Front and middle tibia without a spine, the outer tip of tibia with a curved, transverse, projecting lamella, behind which the surface is shining and scoop-like Margin of tip of mandible straight and at an oblique angle to outer margin, about half as long as mandible Similar Genera: Anthidium, Anthidiellum, Dianthidium, Stelis, Trachusa

Rare, but known to occur abundantly in at least one arboretum

Front of the mesepisternum (side facing the the head) NOT divided from the outer facing side by a sharp edge or carina

Front and middle tibia without a spine, the outer tip of tibia with a curved, transverse, projecting lamella, behind which the surface is shining and scoop-like

Margin of tip of mandible straight and at an oblique angle to outer margin, about half as long as mandible

Similar Genera: Anthidium, Anthidiellum, Dianthidium, Stelis, Trachusa

Uncommon, garden exception

Stelis Rare, one quarter to two-thirds the size of the honeybee Nest parasites on Osmia, Megachile, Heriades, and Ashmeadiella and thus have no scopa on the underside of their abdomens like most other Megachilidae species A variety of body types from very bright and colorful like Anthidium to dark and small like Heriades, some of these groups have been assigned Genus status in the past Similar Genera: Trachusa, Anthidium, Anthidiellum, Dianthidium, Paranthidium, Heriades, Ashmeadiella, Chelostoma

Rare, one quarter to two-thirds the size of the honeybee

Nest parasites on Osmia, Megachile, Heriades, and Ashmeadiella and thus have no scopa on the underside of their abdomens like most other Megachilidae species

A variety of body types from very bright and colorful like Anthidium to dark and small like Heriades, some of these groups have been assigned Genus status in the past

Similar Genera: Trachusa, Anthidium, Anthidiellum, Dianthidium, Paranthidium, Heriades, Ashmeadiella, Chelostoma

Uncommon, parasites of Hoplitis, Osmia, Heriades, Ashmeadiella 12 Species

Trachusa Uncommon to rare, about the size of a honeybee Front edge of scutum clearly raised above the pronotal collar Similar Genera: Stelis, Anthidium, Anthidiellum, Paranthidium, Dianthidium

Uncommon to rare, about the size of a honeybee

Front edge of scutum clearly raised above the pronotal collar

Similar Genera: Stelis, Anthidium, Anthidiellum, Paranthidium, Dianthidium

Uncommon, southern, 5 species

Hoplitis Relatively common dark brown, spring to early summer species Parapsidial line on scutum long and similar to most other bee species Males often have modified antennae with hooked ends or expanded segments Similar Genera: Osmia, Heriades, Chelostoma, Ashmeadiella

Relatively common dark brown, spring to early summer species

Parapsidial line on scutum long and similar to most other bee species

Males often have modified antennae with hooked ends or expanded segments

Similar Genera: Osmia, Heriades, Chelostoma, Ashmeadiella

Relatively common 8 species

Osmia Common spring to early summer species, ranging from one-third the size of a honeybee to slightly larger The majority of species are dark blue (often appearing black in the field) with a few that are brown, black, and one rare bright green one The parapsidial line of the scutum contracted to a line that is usually only 2-5 pit diameters long and is often difficult to find amidst the surface pitting Differentiating males is particularly tricky as many of the best characters are on the underside of the abdomen and often hidden by retracted segments and curled abdomens Similar Genera: Hoplitis, Ashmeadiella, Heriades, Chelostoma

Common spring to early summer species, ranging from one-third the size of a honeybee to slightly larger

The majority of species are dark blue (often appearing black in the field) with a few that are brown, black, and one rare bright green one

The parapsidial line of the scutum contracted to a line that is usually only 2-5 pit diameters long and is often difficult to find amidst the surface pitting

Differentiating males is particularly tricky as many of the best characters are on the underside of the abdomen and often hidden by retracted segments and curled abdomens

Similar Genera: Hoplitis, Ashmeadiella, Heriades, Chelostoma

Common, spring, hole-nester, 28 species

Ashmeadiella Rare, about one quarter the size of a honeybee Front of the mesepisternum (side facing the head) divided from the outer facing side by a sharp edge or carina Similar Genera: Heriades, Chelostoma, Stelis, Osmia, Hoplitis

Rare, about one quarter the size of a honeybee

Front of the mesepisternum (side facing the head) divided from the outer facing side by a sharp edge or carina

Similar Genera: Heriades, Chelostoma, Stelis, Osmia, Hoplitis

Rare Small 2 species

Chelostoma Rare to Locally Common, Small, about one-quarter the size of a honeybee Skinnier and more elongate than the other Megachilid genera Head unusually long 2 introduced species now spreading slowly from New York and Ontario and pollen specialists on Campanula , 1 native species which is a specialist on Mock Orange ( Philadelphus ) Similar Species: Heriades, Ashmeadiella, Osmia, Hoplitis, Stelis

Rare to Locally Common, Small, about one-quarter the size of a honeybee

Skinnier and more elongate than the other Megachilid genera

Head unusually long

2 introduced species now spreading slowly from New York and Ontario and pollen specialists on Campanula , 1 native species which is a specialist on Mock Orange ( Philadelphus )

Similar Species: Heriades, Ashmeadiella, Osmia, Hoplitis, Stelis

Tiny, elongate, 3 species, 2 introduced

Heriades Uncommon, small, about one quarter the size of a honeybee Has a very sculptured appearance with large diameter pits throughout Upper surface of Propodeum is formed of a narrow row of open square cells defined by prominent raised lines Unique within Megachilidae in that the portion of T1 that faces the thorax is hollowed out and surrounded by a raised line or carina Similar Genera: Ashmeadiella, Chelostoma, Hoplitis, Osmia, Stelis

Uncommon, small, about one quarter the size of a honeybee

Has a very sculptured appearance with large diameter pits throughout

Upper surface of Propodeum is formed of a narrow row of open square cells defined by prominent raised lines

Unique within Megachilidae in that the portion of T1 that faces the thorax is hollowed out and surrounded by a raised line or carina

Similar Genera: Ashmeadiella, Chelostoma, Hoplitis, Osmia, Stelis

Tiny, uncommon to locally common, 3 species

Megachile Moderate to large, common particularly in the summer, from about half to 1.5 times the size of a honeybee Most are black with thin white bands of hair on their abdomens Males of some species have greatly expanded front tibia Cutting edges of the mandibles often very useful in females but best seen by pulling open mandibles when specimens are fresh Unlike genera listed below, has no arolium or pad between the tarsal claws of the legs Similar Genera: Lithurgus, Coelioxys

Moderate to large, common particularly in the summer, from about half to 1.5 times the size of a honeybee

Most are black with thin white bands of hair on their abdomens

Males of some species have greatly expanded front tibia

Cutting edges of the mandibles often very useful in females but best seen by pulling open mandibles when specimens are fresh

Unlike genera listed below, has no arolium or pad between the tarsal claws of the legs

Similar Genera: Lithurgus, Coelioxys

Common in all open environments 40 species

Coelioxys Regular, but sparsely distributed, primarily out in the summer and early fall, most about the size of a honeybee Nest parasites of Megachile and thus the females have no pollen carrying hairs under their abdomens The axillae, which normally hug the edge of the scutellum, flare outwards and the shape of their tips are often diagnostic Females have long, pointed abdomens, the shape of which is often unique Males have an odd cluster of pointed or flattened projections and spines at the end of their abdomen, the pattern of which is also often unique Similar Genera: Megachile, Lithurgus

Regular, but sparsely distributed, primarily out in the summer and early fall, most about the size of a honeybee

Nest parasites of Megachile and thus the females have no pollen carrying hairs under their abdomens

The axillae, which normally hug the edge of the scutellum, flare outwards and the shape of their tips are often diagnostic

Females have long, pointed abdomens, the shape of which is often unique

Males have an odd cluster of pointed or flattened projections and spines at the end of their abdomen, the pattern of which is also often unique

Similar Genera: Megachile, Lithurgus

Parasite of Megachile, pointed rear, arolia, no scopa 24 Species

Lithurgus Rare to locally common 2 native species are cactus ( Opuntia ) pollen specialists The introduced species, L. chrysurus , is spreading slowly out of central New Jersey and eastern Pennsylvania and is a knapweed ( Centaurea ) pollen specialist and can be abundant when found Often overlooked as Megachile (particularly males) but has an arolium or pad between its tarsal claws Females all have a diagnostic and very prominent projecting flange between the clypeus and the antennal bases Both males and females have a 3-lobed tip to the mandible

Rare to locally common

2 native species are cactus ( Opuntia ) pollen specialists

The introduced species, L. chrysurus , is spreading slowly out of central New Jersey and eastern Pennsylvania and is a knapweed ( Centaurea ) pollen specialist and can be abundant when found

Often overlooked as Megachile (particularly males) but has an arolium or pad between its tarsal claws

Females all have a diagnostic and very prominent projecting flange between the clypeus and the antennal bases

Both males and females have a 3-lobed tip to the mandible

Rare, 2 cactus specialists, 1 introduced

Resources Species lists, Identification Guides, and Maps for genera and species are available at: http://www.discoverlife.org/20/q?search=Apoidea A guide to the genera of the bees of Canada is available at: http://www.biology.ualberta.ca/bsc/ejournal/pgs_03/pgs_03.html Mitchell’s 1960’s book on the bees of the Eastern United States is available as a series of pdf files at: http://insectmuseum.org/easternBees.php A slightly out of date guide to the identification of the genera of ALL of North America is available at: http://www.knoxcellars.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=KCNP&Product_Code=BGNA&Category_Code=BL

Species lists, Identification Guides, and Maps for genera and species are available at:

http://www.discoverlife.org/20/q?search=Apoidea

A guide to the genera of the bees of Canada is available at:

http://www.biology.ualberta.ca/bsc/ejournal/pgs_03/pgs_03.html

Mitchell’s 1960’s book on the bees of the Eastern United States is available as a series of pdf files at:

http://insectmuseum.org/easternBees.php

A slightly out of date guide to the identification of the genera of ALL of North America is available at:

http://www.knoxcellars.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=KCNP&Product_Code=BGNA&Category_Code=BL