My position is Research Associate in the Invertebrate Zoology Department at the Milwaukee Public Museum (MPM) which has the good fortune of housing an extensive synoptic collection of Western Hemisphere Caraboidea accumulated by retired Dr. Gerald Noonan.
All my published articles are downloadable in one place at ResearchGate
. Backgrounds for these articles (and more) are detailed below.
Note to photographers:
Using my name as an example, there are two different ways to correctly associate your photograph with “PW Messer” as the determiner of the beetle species. If the identification was based on my physical examination of the photo-vouchered specimen, then simply write “det PW Messer 2015”. If identification was based solely on the image, then choose either “image-based det PW Messer 2015” or “photo-ID PW Messer 2015”. Greater chance of inaccuracies are expected with non-physical determinations.
These standard & novel shortcuts appear in PWM caraboid notes: @
reposited at (institution or individual); ©
precedes owner of something original (image, provisional name of undescribed species, etc.); ABL
apparent body length = OBL
overall length from mandible tip to elytral apex estimated to nearest 10th of millimeter; acc.
accompanied with (e.g. ♀ acc. ♂ det PWM); a/s
anal setae pairs (number useful for sexing); b
base (e.g. subscripted in PᵦW = width of pronotal base); BG BugGuide
(e.g. BG 1234 = BugGuide.net/node/view/1234) cf.
compare to; conf.
consistent with; DB
= DataBased; det
differential diagnosis (closest species); E
example(s) = specimen(s); F
= ♀ female; fr
head (includes eyes); ICZN International Code of Zoological Nomenclature
(current 4th ed. = 1999); alphatype
= chosen representative (prime exemplar) of a held species; koft
known only from type species or type locality; L
length (e.g. EL, PL); leg.
field collector; Lth
Carl H. Lindroth's The Ground Beetles of Canada & Alaska
= ♂ male; MCZ Museum of Comparative Zoology
(e.g. MCZ 5886 = mczbase.mcz.harvard.edu/guid/MCZ:Ent:5886); m/s
no date; nr.
near; % o
bservation by; P
pronotum; pers. com.
personal communication; prob.
provisional/pro tempore/temporary; ptk
permitted to keep; PWMC
= Peter W. Messer collection; q.v.
see text or graphics in another part; rec. n.
record new (state or province); SBL
standardized body length that excludes mandible and neck (~ 10% less than ABL); (sic)
foregoing wording or spelling is intentional; sp. n.
species new; syn.
to be confirmed; tbd
to be determined; tbr
to be returned; typ
width (e.g. HW, PW); w/o
Yves Bousquet (e.g. YB 2010
, YB 2012
); → moved to; ±
more or less; ~
approximate, similar to; ¢
"sense" = IC
"I see" = !
Lindroth's autopsy sign placed in front of personal comment; ∵
because, based on; ∴
therefore; ꜝꜞ input by PWM delimited by parenthetic opening ꜝ and closing ꜞ (used to identify supplementary remarks that lie embedded in another person's account); ‼
taxon recently affected by change of status, priority, or spelling (e.g. Harpalus vagans
= phallus (φαλλος) or aedeagus; ȸ d
ased or genitalia sufficiently protruding (e.g. ȸ Amara rubra
to be dissected with open scissors; 8=
dissected done with closed scissors; $
sexing externally is typically unreliable or difficult for the given taxonomic entity (e.g. Scarites
please turn over; ⎕
more in the PWM notebook; [o]
hi res focus-stacked photo.
My interest in carabidology began with a survey of Wisconsin Ground Beetles sensu lato
that I conducted from literature searches, collection inventories, and field work. Ten years of such study culminated in the article An Annotated Checklist of Wisconsin Ground Beetles
published in the The Great Lakes Entomologist
vol 42, nos. 1 & 2, pp 30-61, 2009. A downloadable PDF is available here
. A 2014 update to the Wisconsin checklist is detailed here
I recognize the current hierarchal classification of the Ground Beetles to be as follows.
: suborder Adephaga
: superfamily Caraboidea
= Ground Beetles sensu lato
: families Trachypachidae
. The latter family (= Ground Beetles sensu stricto
) includes the popular subfamily Cicindelinae
(= Tiger Beetles
Both terms "carabid" and "ground beetle" are often used informally to mean any member of Geadephaga. Strictly speaking however, "carabid" refers to just family Carabidae and "caraboid" refers to the widest sense of a ground beetle, that is, the designation "Ground Beetles sensu lato
" noted above.
Readers interested in following/contributing ground beetle species records that were not recorded in the comprehensive 2012 catalogue by Yves Bousquet
are welcome to visit the post-2012 Caraboid Registry
which I manage.
Much of my free time has turned into a lifetime commitment of putting accurate names on caraboid material from Wisconsin. Most challenging in this respect are the vast unidentified holdings at two institutions: University of Wisconsin - Madison (Insect Research Collection = WIRC) and the Milwaukee Public Museum (MPM).
Focused on taxonomy, I am constantly expanding my synoptic collection of the entire Geadephaga of North America. Receiving "photo-voucher" specimens from BugGuide members has worked well in this respect. For example, the set of specimens sent to me from BugGuiders Tom Murray and Jeff Gruber was the stimulus for writing an article on the taxonomic resurrection of Stenolophus thoracicus Casey
(subsequently moved to combination Agonoleptus thoracicus
). BugGuider Tim Moyer sent me a photo-vouchered specimen that represented the first North American record of Elaphropus quadrisignatus
. That discovery is referenced in a coauthored article
about several new state records for Virginia and the District of Columbia.
My key to the North American & Mexican species of Pseudaptinus (Thalpius)
appeared in ZooKeys 147 (2011)
. Since then I have discovered the 11th American Thalpius
, namely T. simplex
in AZ & TX, plus four undescribed species from southwestern USA and Mexico. A follow-up paper is now needed.
As a BugGuide editor, I take particular interest in maintaining informative pages that describe the North American species of Discoderus
, and Scarites
A paper coauthored with Brain Raber on the Nearctic Selenophorus
was published in the March, 2021 issue of The Coleopterists Bulletin(1)
. This review reported eight new species, new synonyms, and several range extensions. Similar work on Nearctic Discoderus
has begun. I am accepting specimens for study.
Robert Davidson and I will describe a new species of Rhadine
from Nebraska/Kansas in conjunction with a new key to the relevant larvalis species group
. Please see my call for specimens/records
of any Rhadine
from the north-central states.
See either a published paper or enter my last name at The Coleopterists Society searchable Directory
Instructions for mailing North American ground beetle specimens (adults) for species identification:
Mailing specimens to me requires our prior mutual agreement. Those who are not familiar with safe mailing of fragile specimens will want to read the following algorithm:
1. Specimen is brittle dry (mounted or not mounted) → go to 2. or
Specimen is either flexible fresh (just caught or saved in freezer) or it is already stored for some time in alcohol (at least 70% ethyl or isopropyl) → go to 4.
2. Dry specimen is already properly pin-mounted or card-pointed? Yes → 3. No → 5.
3. Insect pinning box with cover is available for packing inside a slightly larger cardboard box used for shipping? Yes → done. No → 5.
4. The relaxed specimen is transferred to either a small vial or
small zip locked plastic bag (each partially filled with alcohol) ready to be packed inside a small cardboard shipping box. See #5 for further details.
5. If specimen is not flexible fresh, then drop it into hot water for 20 minutes. The relaxed specimen (along with its own data label if unique) is then lightly wrapped in an alcohol-dampened paper towel strip. Avoid cotton which snags appendages. The individual wrapping is placed inside a small plastic (ziploc) bag along with others. The bag is packed inside the shipping box.
If the mailed specimen is exactly the one posted on BugGuide, then the minimum data on a label associated with the specimen can be just its posted BugGuide number. However, feel free to add collection data. If the specimen is not posted anywhere, then the minimum data should be: State, County, Locale, Date, Collector. Ideally for me, the included data label is a complete permanent laser-printed one, which is usually the case when the specimen is pinned. A temporary label should be hand-printed using either pencil
or a Micron (Pigma) pen. Such permanent or temporary labels can be safely suspended in alcohol if necessary. Avoid ballpoint ink
which bleeds on paper exposed to alcohol. Specimens mailed in just a paper envelope will surely get crushed.
U.S. Postal Parcel is an economical and reasonably safe way to mail specimens. See above Directory for my postal mailing address. In return for my retaining specimens as "photo-vouchers" or otherwise, I will deliver the species identifications to you through either personal e-mail or my comments posted on BugGuide.
Unfortunately, several speciose genera in North America (notably Bembidion, Bradycellus, Elaphropus, Paratachys, Pterostichus
-complex) are currently not fully represented by published taxonomic keys. The underrepresentation pertains mostly to the far western fauna for which I cannot promise successful species identifications.
Your photo-vouchered specimens are scientifically prepared (pinned and labeled with data, collector name, BugGuide photo number) and will eventually be deposited in parts to WIRC and MPM. Thank you for contributing to this comparative reference collection of North American Geadephaga.
"Finding myself ever gravitating to the ground
"Life has become totally carabid-centric with my head always either in the clouds (contemplating a species) or in the sand (searching for another)." PWM
"Those with similar appetite will find me out standing in my field, breaking new ground, and ever grinding away as I harvest more ground beetles to consume!" PWM
"As overlooker I oversee the oversights of those who overlook." PWM
"Pay no attention to my name as I don't peter out easily and I don't really mess around either, although some days I feel as self-professed poster child for the Peter Principle." Peter Messer (ö)