[Pollinator] A Report on Missing Eastern North American Bee Species

[Sam Droege]

All:

Below is a copy of a small report we have put together regarding 47 bee 
species that have not been detected in Eastern North America during the 
past 20 years.  This report along with an Excel Spreadsheet with lots of 
detailed information is located at our ftp site:

ftp://ftpext.usgs.gov/pub/er/md/laurel/Droege/

The documents are:
48 Missing Species Summary.doc
48 Missing Species Summary.docx
Bee Conservation Status5.xls
Bee Conservation Status5.xlsx

Feel free to distribute widely

sam

Sam Droege  sdroege at usgs.gov 
w 301-497-5840 h 301-390-7759 fax 301-497-5624
USGS Patuxent Wildlife Research Center
BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD  20705
Http://www.pwrc.usgs.gov

In nature's infinite book of secrecy
A little I can read
 Antony and Cleopatra - Shakespeare



A Summary of the Facts and Patterns Associated with 47 Species of Bees not 
Detected in the Past 20 Years in Eastern North America (1990 ? 2009)
Authors*:  M. Arduser, J. S. Ascher, J. Cane, S. Colla, M. Deyrup, S. 
Droege**, J. Gibbs, T. Griswold, G. Hall, C. Henne, H. Ikerd, A. Mayor, J. 
Neff, R. Jean,  M. Rightmyer, C. Sheffield, M. Veit, A. Wolf , D. Yanega
*Authors include anyone who submitted information regarding the status of 
a species and are presented in alphabetical order, actual contributions 
varied greatly.
**Corresponding author is Sam Droege(sdroege at usgs.gov)
Scope
This report seeks to address the simple question of whether there are 
species of bees in Eastern North America that have become so uncommon that 
they have not been seen during the last 20 years (1990 ? 2009). Using this 
list of missing species we hope to stimulate more in-depth investigations 
of population status and to initiate lists of conversation concern among 
regional and national conservation and management groups.  Our foundation 
is a list of all bee species known to have occurred east of the 
Mississippi River in the United States and from Ontario East in Canada 
(see attached Excel spreadsheet).   This list was compiled and provided by 
John Ascher, and John also provided lists of individual state and 
provincial records. 
There are approximately 800 recorded species in the region.  The number of 
species must be qualified due both to the presence of unpublished new 
species and to unpublished synonymies; a testament to the incomplete 
nature of even such a basic thing as a stable list of names for the bees 
present in North America.  This list was passed around the very small 
world of all known North American bee experts for review and comment and, 
as the list was truncated, it was iteratively reviewed until no more 
changes were made.
 From these 800 or so species, 47 (6%) have not been seen or collected by 
anyone in the last 20 years (See list with notes in the attached Excel 
File).
 These 47 missing species are not a random assemblage of all bee species, 
but a group with strong associations with certain categories or guilds and 
these are outlined below. 
Categories of Patterns
 Rarity
All these species can be said to have been rare to uncommon in collections 
and thus, at minimum, have always been uncommon species.  Some are known 
only from single specimens, others from but a few.
Parasitic Lifestyle
Nineteen species are known to be inquilines or nest parasites of other 
species.  These come from the parasitic genera  Epeolus, Nomada, 
Sphecodes, Stelis, and Triepeolus and may possibly also include  
Lasioglossum wheeleri.
Geographic Localities
Within the East certain patterns emerge regarding the geographic 
distributions of the species on the missing list.  Few species are 
restricted to the middle latitudes, while over half (25) are from the Deep 
South and, of those, eight have only been collected from within the 
comparatively small landmass of the Florida peninsula.   A few species 
have a distribution primarily from the Great Plains and to the west and 
nine species are northerly in distribution.  Such geographic patterns are 
likely a reflection of both true patterns of rarity (often associated with 
sandy areas) and lack of recent collection activity in these areas.
Taxonomic Ambiguity
A number of species are members of poorly studied genera, have been found 
only once, or their identification is difficult or controversial.  Their 
existence on this list may simply be due to lack of scrutiny.  We suspect 
this may possibly be the case for:  Epeolus banksi, Epeolus vernalis, 
Lasioglossum wheeleri, Melissodes pilleata, and potentially all of the 
Sphecodes.
Pollen Specialty
As most of these species were rare to begin with, little is directly known 
of their associations with plant genera.  That said, many of the 
non-parasitic species are members of bee genera that commonly restrict 
themselves to collecting pollen only from a limited number of plant 
species.   Thus, if those plants species are rare, or collectors do not 
happen to collect from those plants, then species may go undetected for 
long periods of time.
Implications
Common Species Remain Common
No species of bee that could, in the past, be called common or abundant 
appears on the list of missing species; consolation to small degree that 
any recent changes to bee populations has not been so dramatic as to cause 
our common bees to disappear.  The only exception to this is the 
disappearance or near disappearance of several bumblebee species.   While 
all the bumblebee species have been detected in the last 20 years, 
catastrophic declines have been demonstrated only within the last 10 
years.   That these declines were detectable creates the hope that at 
least for other common bee species, large scale declines would be noticed.
More Collecting  Required
Clearly it is possible that many of these missing species may still be 
present but simply not detected.  Evidence for that comes from the 
reasonably large number of the species that were detected but only 
occurred as single individuals (this was unfortunately not quantified). 
The high numbers of missing Deep South and Florida species mirrors the 
general lack of collecting in these regions during the last 20 years, 
particularly in comparison to past efforts of the late T. Mitchell of 
North Carolina and his network of southern correspondents and collectors.
Institutional Support for Museums and Collections
In the past museums, collections, and their staff within states, 
provinces, and academic institutes functioned as regional sources of 
information about bee populations and status.  Currently, there is a grave 
outright loss of these collections and, for those that remain, we know of 
none that are supported even to the level they were in the previous 
century.
Creation of a Tracking Mechanism
While there is no formal monitoring system in place for bees, the fact 
that drastic declines can occur (e.g., the crash of bumblebee 
populations), the importance of bees to agricultural security and the 
propagation of native plants, and the overall interest in this group of 
species argues for the creation of some form or inventory, monitoring, or 
periodic assessment of population status.
Support for Collecting and Surveying Bees
Rare and uncommon bees are unlikely to be regularly captured in a 
monitoring scheme.   Monitoring schemes usually fix placement of survey 
traps and tend to favor the tracking of common species over the detection 
of rare ones.  Rare bees are best captured by people specifically looking 
for rare bees.  Large geographic coverage and specialized habitats (e.g., 
deep sand or bogs) need to be purposefully searched via regional 
inventories.   Rare bees are found by capturing and processing large 
numbers of bees and having those bees identified by experts.
To facilitate the detection of rare bees is to facilitate those who would 
capture, process, curate, and identity those bees.   These activities have 
waned over the past 100 years as people have moved indoors and 
universities have emphasized molecular work over traditional morphological 
revisions.   It would be very useful to create a society similar to that 
in the United Kingdom that promotes the collecting and the detection and 
tracking of rare species; create up-to-date regional  and national 
annotated lists of bees; develops bee identification tools; create courses 
that teach people how to identify bee species;  databases existing 
collections of native bees; and creates new tracking and reporting 
databases for bees currently being collected.
What to do About the Species Currently on this List?
First, it would make sense for state, provincial, and national Heritage 
departments to add these species to their Heritage ranking schemes.  It 
would also make sense to perform specific surveys for these species to 
determine more fully their status and hopefully learn more about their 
Life History.  One should assume for now that these species are still 
present somewhere and hopefully not extinct.  At minimum, a literature and 
specimen review should be created that explores what is known about past 
geographic and times of occurrence, habitat preferences, hosts, and floral 
records for each of these species and from that gathering create a plan 
for further study and ultimately re-detection and conservation.
How Should This Report be Used?
This report reflects the opinions and experiences of the above listed 
authors and should not be construed as any form of endorsement by the 
author?s funders or places of employment.
Date of Last Editing:  8/05/2010


P Bees are not optional.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sonic.net/pipermail/pollinator/attachments/20100805/c471256c/attachment-0001.html>