Epeoloides pilosulus (Cresson 1878) is one of the rarest bees in North America with only a handful of records since 1960. The last collection in Michigan was made in 1944. Epeoloides pilosulus is a brood parasite of Macropis bees, which until recently had not been collected in Michigan for several decades. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus in this state – the first record in 74 years. Michigan becomes the fourth state where E. pilosulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly recorded for the state

Gibbs, Jason

Graham, Kelsey K

Isaacs, Rufus

Killewald, Michael F

Wood, Thomas J

English

ValpoScholar

The Great Lakes Entomologist 
Volume 52 
Numbers 1 & 2 - Spring/Summer 2019 Numbers 
1 & 2 - Spring/Summer 2019 
Article 4 
September 2019 
Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with 
Notes on the Distribution and Status of its Macropis hosts. 
Thomas J. Wood 
Michigan State University, thomaswood734@gmail.com 
Michael F. Killewald 
Michigan State University, killewam@myumanitoba.ca 
Kelsey K. Graham 
Michigan State University, graha252@msu.edu 
Jason Gibbs 
University of Manitoba, jason.gibbs@umanitoba.ca 
Rufus Isaacs 
Michigan State University, isaacsr@msu.edu 
Follow this and additional works at: https://scholar.valpo.edu/tgle 
 Part of the Entomology Commons 
Recommended Citation 
Wood, Thomas J.; Killewald, Michael F.; Graham, Kelsey K.; Gibbs, Jason; and Isaacs, Rufus 2019. 
"Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its 
Macropis hosts.," The Great Lakes Entomologist, vol 52 (1) 
Available at: https://scholar.valpo.edu/tgle/vol52/iss1/4 
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Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the 
Distribution and Status of its Macropis hosts. 
Cover Page Footnote 
Acknowledgements Survey work was funded by USDA NIFA grant 2017-68004-26323. Our thanks go to 
Gary Parsons for access to the insect collection at MSU, to The Little Forks Conservancy for allowing 
access to the Averill site, and to The Nature Conservancy for allowing access to the Ives Road Fen site. 
This peer-review article is available in The Great Lakes Entomologist: https://scholar.valpo.edu/tgle/vol52/iss1/4 
2019 THE GREAT LAKES ENTOMOLOGIST 1
The status of wild bee species and 
populations has been the subject of a great 
deal of attention by the scientific community 
in recent years, with rapidly contracting 
distributions for bees such as Bombus affinis 
Cresson documented in the United States 
and Canada (Colla and Packer 2008; Cam-
eron et al. 2011). Understanding population 
declines in wild bees outside of the genus 
Bombus has been more difficult, in part be-
cause many solitary bee species are rare in 
collections, either because they have small 
geographic ranges or because they are phe-
nologically limited to a narrow flight period 
and require specialized collection effort in 
order to detect (Harrison et al. 2017). Indeed, 
in a study of the population trends of wild 
bees in the northeastern United States, 87 
of the 438 species (19.9%) were represented 
by only 10 to 30 specimens over a 140-year 
period, making assessment of their historic 
and contemporary statuses challenging 
(Bartomeus et al. 2013).
One bee species that has been very 
infrequently recorded in North America is 
Epeoloides pilosulus (Cresson). Epeoloides 
pilosulus is a brood parasite of Macropis bees 
(Sheffield et al. 2004; Wagner and Ascher 
2008), which are themselves specialists on 
Lysimachia species (Fig. 1A, Primulaceae), 
collecting pollen and floral oils exclusively 
from this genus (Michez and Patiny 2005). 
Floral oils are mixed with pollen provisions 
and used to waterproof the linings of the cell 
wall (Cane et al. 1983), allowing Macropis to 
nest in the damp soils favored by Lysimachia 
species (Fig. 1B). Epeoloides pilosulus is thus 
twice restricted; first by the limited suite of 
bee species that it parasitizes and second 
by the narrow ecological niche occupied by 
its hosts.
Epeoloides pilosulus is consequently 
very rarely collected. Most specimens in 
Michigan were collected in the early part of 
the 20th century with the last record made 
in 1944. This fits into the overall trend for 
E. pilosulus, as the species was not recorded 
in North America between 1960 and 2002 
(but see Sheffield and Heron 2018), until 
it was rediscovered in Nova Scotia based 
on two male specimens collected in a pan 
trap (Sheffield et al. 2004). There have only 
been four additional contemporary records 
of E. pilosulus in North America since then, 
in Connecticut (2006, Wagner and Ascher 
2008), Alberta (2010, Sheffield and Heron 
2018), New York (2014, http://bugguide.
net/node/view/954741), and Maine (2016, 
Dibble et al. 2017). In Michigan, E. pilosulus 
is known from four counties in the central 
and southern Lower Peninsula (Berrien, 
Midland, Van Buren, and Wayne).
Epeoloides pilosulus (Cresson) (Hymenoptera: Apidae) 
Rediscovered in Michigan, with Notes on the 
Distribution and Status of its Macropis Hosts
T.J. Wood1,2*, M.F. Killewald1,3, K.K. Graham1, J. Gibbs3 and R. Isaacs1
1 Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA
2 Current affiliation: Laboratory of Zoology, University of Mons, 7000, Mons, Belgium
3 Department of Entomology, University of Manitoba, 12 Dafoe Rd., 
Winnipeg, MB, R3T 2N2, Canada
*Corresponding author: (e-mail: thomasjames.wood@umons.ac.be)
Abstract
Epeoloides pilosulus (Cresson 1878) (Hymenoptera: Apidae) is one of the rarest bees 
in North America with only a handful of records since 1960. Epeoloides pilosulus is a brood 
parasite of Macropis bees, which until recently had not been collected in Michigan since 
1944. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus 
in this state – the first record in 74 years. Michigan becomes the fourth state where E. pi-
losulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 
2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. 
State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 
1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly 
recorded for the state.
Key words: parasitic bee, oil bee, oligolege, bee surveys, Lysimachia
1
Wood et al.: Epeoloides pilosulus rediscovered in Michigan
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2 THE GREAT LAKES ENTOMOLOGIST Vol. 52, Nos. 1–2
Only one species of Macropis has been 
recorded from Michigan – Macropis nuda 
(Provancher). Macropis nuda has a large 
range and is known from Canada, from 
British Columbia to Nova Scotia, and the 
United States, from Montana and Colorado 
to the New England states (Mitchell 1960; 
Michez and Patiny 2005; Sheffield and Heron 
2018). However, like E. pilosulus, M. nuda 
appeared to have disappeared from Mich-
igan, being last recorded in 1959 and not 
rediscovered until 2017 in Hillsdale County 
(Gibbs et al. 2017).
The aim of this paper is to report on the 
findings of recent bee faunal surveys across 
Michigan that include the rediscovery of E. 
pilosulus and have expanded our under-
standing of the status of Macropis species 
in the state.
Figure 1. A. Fringed Loosestrife (Lysimachia ciliata L.) flower. B. Lysimachia ciliata in flower in damp 
prairie fen habitat at Ives Road Fen, Lenawee County. C. European Dotted Loosestrife (Lysimachia 
punctata L.) outside an abandoned house in Felch, Dickinson County. D-F. Macropis nuda (Provancher) 
individuals at Algonac State Park, St. Clair County. D. Macropis nuda male showing distinctive yellow 
facial maculations. E-F. Macropis nuda female collecting pollen from L. ciliata.
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2019 THE GREAT LAKES ENTOMOLOGIST 3
Methods
As part of our Michigan bee survey 
we visited the Averill Preserve (43.6618, 
–84.3500; managed by Little Forks Conser-
vancy) in Midland County every other week 
from mid-June to mid-September in 2017 
and 2018. During each visit, we spent one 
cumulative hour sampling bees using aerial 
nets, and we recorded which plants bees were 
caught on. Surveys focused on open habitats, 
with surveyors searching all flowering plants 
within these areas. Similar sampling meth-
ods were used at seven other sites in Mid-
land, Ingham, Shiawassee, Kalamazoo, and 
Livingston counties. All bees were pinned 
and labelled at Michigan State University, 
and then identified to species at the Uni-
versity of Manitoba (JG and Joel Gardner). 
During collection at the Averill Preserve, a 
specimen of E. pilosulus was captured (see 
Results). This material is deposited in the 
Albert J. Cook Arthropod Research Collec-
tion at Michigan State University.
The records of Macropis species for 
Michigan stated in this paper are based on 
the collections of the lead author as part of 
his efforts to survey wild bees in every county 
in Michigan. His material is deposited at 
the J.B. Wallis / R. E. Roughley Museum 
of Entomology, University of Manitoba. 
Historic records of E. pilosulus and M. nuda 
collections were taken from the most recent 
summary of the Michigan bee fauna (Gibbs 
et al. 2017).
Results
Epeoloides pilosulus (Cresson 1878)
Current records: Midland Co.: Mid-
land, Averill Preserve, 43.6618, –84.3500, M. 
Killewald, 28 June 2018, 1♀, (BH_010955), 
Lysimachia nummularia L.
The specimen was collected as it was 
patrolling a small patch of L. nummularia 
flowers along a walkway.
Macropis (Macropis) nuda 
(Provancher 1882)
Current records: Alcona Co.: 
Black River, Black River Road x La Vigne 
Road, 44.815, –83.324, T.J. Wood, 15 July 
2018, 1♀, Apocynum androsaemifolium L.; 
Alpena Co.: Mackinaw State Forest, Long 
Rapids Rd x Truax Creek, 45.116, –83.823, 
T.J. Wood, 15 July 2018, 1♂, 1♀, Lysima-
chia ciliata L.; Dickinson Co.: Foster City, 
Felch, 45.996, –87.825, T.J. Wood, 30 June 
2018, 2♂, Lysimachia punctata L., Fig. 2C; 
Hillsdale Co.: Pittsford State Game Area, 
41.866, –84.522, T.J. Wood, 8 July 2017, 1♂, 
Apocynum cannabinum L.; St. Clair Co.: 
Algonac State Park, 42.650, –82.531, T.J. 
Wood, 14 July 2018, 1♂, 1♀, L. ciliata, Fig. 
1D–F; Tuscola Co.: Dayton, S Plain Road 
x James Road, 43.462, –83.268, T.J. Wood, 
25 June 2018, 1♂, 1♀, L. ciliata.
Macropis nuda was not known from 
Alcona, Hillsdale, St. Clair and Tuscola coun-
ties prior to its discovery there in 2017–2018. 
The historic and contemporary distributions 
are shown in Fig. 2A.
Macropis (Macropis) patellata  
Patton 1880
Current records: Lenawee Co.: Ives 
Road Fen Preserve, 41.967, –83.945, T.J. 
Wood, 8 July 2018, 3♂, L. ciliata.
Males and females were abundant at 
an area of restored prairie fen in south-east 
Michigan with regenerating wetland vege-
tation (Fig. 2B). No females were collected 
as TJW believed at the time that these bees 
were M. nuda, and consequently did not col-
lect any females in order to avoid depleting 
the population. It was not until they were 
inspected under the microscope that their 
true identity was determined.
Discussion
The rediscovery of E. pilosulus in 
Midland County suggests that the species 
has been present in Michigan continuously 
since it was first discovered over a century 
ago. Although M. nuda was not also found 
at the same site, the host and the parasite 
are often detected using different sampling 
techniques, with the parasite detected using 
bowl traps and the host using aerial netting 
in both Nova Scotia and Connecticut (Shef-
field et al. 2004; Wagner and Ascher 2008). 
Contemporary records of M. nuda suggest 
that this species remains most common in 
the Saginaw Bay region of eastern Michigan 
(Fig. 2A).
All pollen foraging M. nuda females 
along with several males were collected 
from Fringed Loosestrife (L. ciliata). This 
is in common with other studies in eastern 
North America (Cane et al. 1983). Males 
were also collected patrolling around the 
introduced European Dotted Loosestrife 
(L. punctata) in Dickinson County (Fig. 
1C), suggesting that it may also be visited 
by females of this species. In Europe, L. 
punctata is visited for pollen and oil by the 
native M. fulvipes (Fabricius) (Michez and 
Patiny 2005). In contrast, the European 
Creeping Jenny (L. nummularia) is not vis-
ited by Macropis species (Cane et al. 1983) 
as it does not produce oil. This may explain 
why E. pilosulus was found at the Averill 
Preserve site but M. nuda was not. Surveys 
3
Wood et al.: Epeoloides pilosulus rediscovered in Michigan
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4 THE GREAT LAKES ENTOMOLOGIST Vol. 52, Nos. 1–2
were restricted to dry, open areas, where no 
other Lysimachia species were present, al-
though they may have been present in damp 
riverine areas nearby. Individual females 
of M. nuda collected on Indian Hemp (A. 
cannabinum) and Spreading Dogbane (A. 
androsaemifolium) showed no evidence of 
pollen collection and were visited solely for 
nectar. Though restricted to Lysimachia for 
pollen and floral oils, Macropis species have 
been recorded visiting many plant families 
for nectar (Pekkarinen et al. 2003; Michez 
and Patiny 2005), including Apocynum by 
M. nuda (Cane et al. 1983).
Macropis patellata is known to occur in 
the eastern United States from North Caro-
lina north to Vermont and west to Iowa and 
Nebraska (Mitchell 1960; Michez and Patiny 
2005; Ascher and Pickering 2018). Surpris-
ingly, the species has never been recorded 
from Indiana or Ohio, so this record from 
south-eastern Michigan fills a distributional 
gap and suggests that, in addition to these 
two states, the species may also be present 
in southern Ontario. Most of the data used 
to determine the distribution of this bee are 
old, and the species was highlighted as po-
tentially being of conservation concern due to 
a lack of recent records in the northeastern 
United States (Bartomeus et al. 2013). The 
two other Macropis species known from 
North America, M. ciliata Patton 1880 and 
M. steironematis Robertson 1891, have a 
similar distribution to M. patellata, being 
found in some Atlantic states and parts of 
the Midwest, but have not been recorded 
from Michigan, Indiana or Ohio (Michez and 
Patiny 2005; Ascher and Pickering 2018). 
Continued targeted searching may reveal the 
presence of one or both of these additional 
Macropis species in this region.
The rediscovery of M. nuda (Gibbs et 
al. 2017) and E. pilosulus, as well as the 
discovery of M. patellata, in Michigan high-
lights some potential consequences of low 
sampling effort for bees over long periods 
of time. These include a high likelihood of 
missing bees that have restricted geograph-
ical ranges or that exploit a narrow range 
of host plants, as well as the potential to 
consider a bee rare when it has instead been 
poorly sampled. The level of active sampling 
for bees in Michigan has, until very recently, 
been low in comparison with the historical 
baseline. The year of the most recent pre-
vious record for M. nuda (1959) coincides 
with the final collection period of R.R. Dreis-
bach, a prolific amateur entomologist who 
collected bees extensively across the whole 
state (Fischer 1965). Macropis nuda and E. 
pilosulus were almost certainly continuous-
ly present in Michigan for the last 60–70 
years, and the absence of records for these 
species likely reflects low sampling effort 
rather than a genuine population decline. 
More regular and extensive sampling is 
needed to inform conservation efforts along 
with targeted searches to understand the 
Figure 2. A. Distribution of Macropis nuda (Provancher) in Michigan at a county-level resolution. The 
single new record of Macropis patellata Patton is marked with an asterisk. B. Distribution of Epeoloides 
pilosulus (Cresson) in Michigan at a county-level resolution. Pre-1960 records are marked in gray and 
2017–2018 records are marked in red. Hatching indicates records of the species in both time periods.
4
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2019 THE GREAT LAKES ENTOMOLOGIST 5
abundance and distribution of specialized 
species that have narrow ecological niches 
which make them difficult to detect. General 
bee surveys in North America are likely at 
an all-time high, but many species of con-
servation concern may best be studied with 
more focused efforts.
Acknowledgments
Survey work was funded by USDA 
NIFA grant 2017-68004-26323. Our thanks 
go to Gary Parsons for access to the insect 
collection at MSU, to The Little Forks Con-
servancy for allowing access to the Averill 
site, and to The Nature Conservancy for 
allowing access to the Ives Road Fen site.
Literature Cited
Ascher, J. S., and J. Pickering. 2018. Dis-
cover Life bee species guide and world 
checklist (Hymenoptera: Apoidea: An-
thophila). http://www.discoverlife.org/
mp/20q?guide=Apoidea_species
Bartomeus, I., J.S. Ascher, J. Gibbs, B.N. Dan-
forth, D.L. Wagner, S.M. Hedtke, and R. 
Winfree. 2013. Historical changes in north-
eastern US bee pollinators related to shared 
ecological traits. Proceedings of the National 
Academy of Sciences 110: 4656–4660.
Cameron, S.A., J.D. Lozier, J.P. Strange, J.B. 
Koch, N. Cordes, L.F. Solter, and T. Gris-
wold. 2011. Patterns of widespread decline 
in North American bumble bee. Proceedings 
of the National Academy of Sciences 108: 
662–667.
Cane, J.H., G.C. Eickwort, F.R. Wesley, and 
J. Spielholz. 1983. Foraging, grooming and 
mate-seeking behaviours of Macropis nuda 
(Hymenoptera, Melittidae) and use of Lysi-
machia ciliata (Primulaceae) oils in larval 
provisions and cell linings. The American 
Midland Naturalist 110: 257–264.
Colla, S.R., and L. Packer. 2008. Evidence for 
decline in eastern North American bumble-
bees (Hymenoptera: Apidae), with special 
focus on Bombus affinis Cresson. Biodiversity 
and Conservation 17: 1379–1391.
Dibble, A.C., F.A. Drummond, C. Stubbs, M. 
Veit, and J.S. Ascher. 2017. Bees of Maine, 
with a State Species Checklist. Northeastern 
Naturalist 24, Monograph 15: 1–63.
Fischer, R.L. 1965. Robert R. Dreisbach. News-
letter of the Michigan Entomological Society 
9: 2–3.
Gibbs, J., J.S. Ascher, M.G. Rightmyer, and 
R. Isaacs. 2017. The bees of Michigan (Hy-
menoptera: Apoidea: Anthophila), with notes 
on distribution, taxonomy, pollination, and 
natural history. Zootaxa 4352: 1–160.
Harrison, T., J. Gibbs, and R. Winfree. 2017. 
Anthropogenic landscapes support fewer rare 
bee species. Landscape Ecology, https://doi.
org/10.1007/s10980-017-0592-x
Michez, D. and S. Patiny. 2005. World revision 
of the oil-collecting bee genus Macropis Pan-
zer 1809 (Hymenoptera: Apoidea: Melittidae) 
with a description of a new species from 
Laos. Annales de la Société Entomologique 
de France 41: 15–28.
Mitchell, T.B. 1960. Bees of the Eastern United 
States: volume I. North Carolina Agricultural 
Experimental Station Technical Bulletin 
141: 1–538.
Pekkarinen, A., O. Berg, I. Calabuig, L-A. Jan-
zon, and J. Luig. 2003. Distribution and 
co-existence of the Macropis species and their 
cleptoparasite Epeoloides coecutiens (Fabr.) 
in NW Europe (Hymenoptera: Apoidea, Mel-
ittidae and Apidae). Entomologica Fennica 
14: 53–59.
Sheffield, C.S., S.M. Rigby, R.F. Smith, and 
P.G. Kevan. 2004. The rare cleptoparasitic 
bee Epeoloides pilosula (Hymenoptera: 
Apoidea: Apidae) discovered in Nova Scotia, 
Canada, with distributional notes. Journal 
of the Kansas Entomological Society 77: 
161–164.
Sheffield, C.S. and J. Heron. 2018. A new 
western Canadian record of Epeoloides pilo-
sulus (Cresson), with discussion of ecological 
associations, distribution and conservation 
status in Canada. Biodiversity Data Journal 
6: e22837.
Wagner, D.L., and J.S. Ascher. 2008. Rediscov-
ery of Epeoloides pilosula (Cresson) (Hyme-
noptera: Apidae) in New England. Journal of 
the Kansas Entomological Society 81: 81–83.
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Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.

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Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.

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