<html>
<body>
John Ascher (and pollinator listserve members), <br>
<br>
Thank you so much for your comments regarding the discussion of bumble
bee declines, and generally for all of your work on the conservation of
native bees. I think you make a very good point when you bring up the
danger in treating pesticides and habitat loss as potential causes of the
decline in bumble bees in the subgenus <i>Bombus</i>. The authors of the
<a href="http://www.xerces.org/wp-content/uploads/2008/12/xerces_2008_bombus_status_review.pdf">
Status Review of Three Formerly Common Species of Bumble bee in the
subgenus
</a>
<a href="http://www.xerces.org/wp-content/uploads/2008/12/xerces_2008_bombus_status_review.pdf">
<i>Bombus</a></i> strongly favor Dr. Robbin Thorp’s hypothesis that
disease from commercially reared bumble bees transmitted to wild
populations is the most likely cause of decline. We favor this hypothesis
over pesticides or habitat for many of the reasons that you presented in
your email, and there is extensive circumstantial evidence for a disease
hypothesis. <br>
<br>
Dr. Thorp laid out the strong circumstantial evidence for his disease
hypothesis in an email to the BOMBUS listserve on 12/19/08. I’ve copied
the most relevant portion of that email below:
<ul>
<li>Declines of these once common species occurred recently, suddenly,
and at the same time over much of the known distribution of each species.
<li>Other species of bumble bees continue to thrive and populations of
some are increasing in the same areas.
<li>The species in decline are all closely related to the European
<i>Bombus terrestris</i>, the most widely disseminated species of
commercially produced bumble bees.
<li>Colonies of <i>B. terrestris</i> imported from Europe to Japan have
been shown to contain <i>Nosema</i> and other pathogenic organisms.
<li>Pathogen “spillover” from commercial bumble bee colonies in tomato
greenhouses to wild populations in Canada has been demonstrated in
Canada.
<li>As to the potential source of contamination and route of entry of
exotic diseases from Europe into NA, colonies of <i>B. occidentalis</i>
and <i>B. impatiens</i> were reared from North American queens in
production facilities in Europe and imported to NA from 1992 through 1994
for commercial distribution.
<li>In 1997, producers of commercial bumble bee colonies in NA reported
infections of <i>Nosema bombi</i> in their <i>B. occidentalis</i>
populations that they could not clean up.
<li>Bumble bee species have been shown to differ in susceptibility to
<i>N. bombi</i>. (This may also explain the inability of the
commercial producers to clean up the infection in their <i>B.
occidentalis</i> populations).
</ul><u>In summary</u>, the cause of the declines in members of the
subgenus <i>Bombus</i> in NA are quite specific to a group of closely
related species. These bumble bees have overlapping forage resource
use and underground nest location preferences with many species of bumble
bees including many <i>Pyrobombus</i> in NA that are showing population
increases (e.g., <i>B. impatiens</i> and <i>B. bimaculatus</i> in the
east, and <i>B. vosnesenskii</i> and <i>B. bifarius</i> in the
west). In addition, other potential causes such as pesticides,
habitat destruction would most likely show a broader impact over a wider
range of bumble bee species.<br>
<br>
Tests of my disease hypothesis will be challenging since the populations
of the bees have declined so severely. Fortunately a group at the
University of Illinois is currently developing methods to test this
working hypothesis. Hopefully there will be more to come in future
regarding the validity of the strong supporting evidence for my disease
hypothesis.<br>
<br>
****<br>
Best, <br>
Sarina Jepsen<br><br>
At 12:00 PM 2/6/2009, you wrote:<br>
<blockquote type=cite class=cite cite="">Send Pollinator mailing list
submissions to<br>
<x-tab> </x-tab>
pollinator@lists.sonic.net<br><br>
To subscribe or unsubscribe via the World Wide Web, visit<br>
<x-tab> </x-tab>
<a href="http://lists.sonic.net/mailman/listinfo/pollinator" eudora="autourl">
http://lists.sonic.net/mailman/listinfo/pollinator</a><br>
or, via email, send a message with subject or body 'help' to<br>
<x-tab> </x-tab>
pollinator-request@lists.sonic.net<br><br>
You can reach the person managing the list at<br>
<x-tab> </x-tab>
pollinator-owner@lists.sonic.net<br><br>
When replying, please edit your Subject line so it is more specific<br>
than "Re: Contents of Pollinator digest..."<br><br>
<br>
Today's Topics:<br><br>
1. Re: Wisconsin Department of Natural Resources to
track<br>
declining bumble bees (John S.
Ascher)<br><br>
<br>
----------------------------------------------------------------------<br>
<br>
Message: 1<br>
Date: Thu, 5 Feb 2009 15:51:46 -0500 (EST)<br>
From: "John S. Ascher" <ascher@amnh.org><br>
Subject: Re: [Pollinator] Wisconsin Department of Natural Resources
to<br>
<x-tab> </x-tab>track
declining bumble bees<br>
To: pollinator@lists.sonic.net<br>
Message-ID:
<1381.216.73.251.75.1233867106.squirrel@webmail.amnh.org><br>
Content-Type: text/plain;charset=iso-8859-1<br><br>
<br><br>
Dear all:<br><br>
I am glad to see this helpful and timely support for bumble bee<br>
conservation by the Wisconsin DNR.<br><br>
I have one concern, not about this press release in particular, which
is<br>
excellent, but about discussion of bumble bee declines in general.<br>
Specifically, I do not think it is helpful to invoke habitat loss
and<br>
pesticide use as an important cause of Bombus (Bombus) declines.<br>
Mentioning these factors may seem appropriate as a matter of fairness
or<br>
completeness, because they might plausibly contribute to any bee
declines,<br>
but in my opinion the available evidence argues against their relevance
in<br>
this case.<br><br>
Most significantly, the timing of abrupt continental-scale declines
in<br>
Bombus (Bombus) and of their Bombus (Psithyrus) social parasites
(likely<br>
at least as threatened as their hosts) does not correspond to any<br>
documented changes in habitat or pesticide use, and the lack of any
known<br>
correspondence with these factors is one of the most salient features
of<br>
these declines. Many and perhaps most bumble bee species belonging
to<br>
other subgenera such as Pyrobombus remain generally abundant, and
Bombus<br>
(Bombus) and their B. (Psithyrus) parasites also remained numerous
until<br>
the mid-late 1990s, despite massive changes in habitat and
pesticide use<br>
across the continent during the 1940s-1990s and before. If a
pesticide<br>
were involved, why should this have differentially harmed Bombus
(Bombus)<br>
and not other related bumble bee subgenera such as Bombus
(Pyrobombus)?<br><br>
Invoking general causes potentially relevant to declines in any bee
taxa<br>
does not help to correctly identify the precise biological and<br>
sociological reasons why Bombus (Bombus) declined abruptly and
drastically<br>
whereas most other bee taxa remained numerous in the same habitats
with<br>
presumably the same or similar pesticide exposures. Whatever the
relevant<br>
causes, they are definitely particular to Bombus (Bombus) and do not
apply<br>
to other bumble bee subgenera such as Pyrobombus. In addition to
being<br>
taxon-specific, the relevant causes must date precisely to the mid
1990s.<br><br>
Inclusion of imprecise and irrelevant causes when discussing the
Bombus<br>
(Bombus) and B. (Psithyrus) declines of greatest concern only helps
to<br>
diffuse what should be a sharply focused effort to identify the true<br>
causes and responsible parties and to prevent future declines of
this<br>
sort.<br><br>
Loss of nesting habitat and floral resources is plausible as a
primary<br>
cause of large-scale declines in certain bumble bee species such as
B.<br>
pensylvanicus and their parasite B. variabilis, but declines in
these<br>
species seem to have begun long before the mid-1990s and do not
correspond<br>
in timing or extent with those of Bombus (Bombus) and B.
(Psithyrus).<br><br>
In my opinion it is best to discuss events believed to be causally<br>
unrelated separately, even if this may require us to contend with<br>
burdensome concepts such as bumble bee subgenera.<br><br>
John<br><br>
<br><br>
<br>
> Email not displaying correctly? View it in
your<br>
>
browser.<<a href="http://www.xerces.org/press-releases/wisconsin_bumble_bees.html" eudora="autourl">
http://www.xerces.org/press-releases/wisconsin_bumble_bees.html</a>
><br>
>
<<a href="http://www.xerces.org/press-releases/wisconsin_bumble_bees.html" eudora="autourl">
http://www.xerces.org/press-releases/wisconsin_bumble_bees.html</a>
><br>
>
<<a href="http://www.xerces.org/press-releases/wisconsin_bumble_bees.html" eudora="autourl">
http://www.xerces.org/press-releases/wisconsin_bumble_bees.html</a>
><br>
><br>
> For Immediate Release<br>
> February 4, 2009<br>
><br>
> Contacts:<br>
> *Eric Mader*, National Pollinator Outreach Coordinator, The Xerces
Society;<br>
> (608) 628-4951<br>
> *Bill Smith*, Natural Heritage Inventory Program Zoologist, WI
DNR;<br>
(608)<br>
> 266-0924<br>
><br>
> WISCONSIN DEPARTMENT OF NATURAL RESOURCES<br>
><br>
> TO TRACK DECLINING BUMBLE BEES<br>
><br>
> Madison, WI: Two of Wisconsin's bumble bees have been added to
the<br>
Wisconsin<br>
> Department of Natural Resources' Special Concern List.<br>
><br>
> This action, a response to dramatically declining populations of
the<br>
yellowbanded bumble bee (*Bombus terricola*) and the rusty-patched<br>
bumble<br>
> bee (*Bombus affinis*), will result in official monitoring of
both<br>
species<br>
> through the DNR's Natural Heritage Inventory database. Field
biologists<br>
will<br>
> now start keeping records of when and where these species are
found.<br>
Over<br>
> time, this database will provide a picture of the bees' abundance
and<br>
distribution in the state.<br>
><br>
> "This is a very significant step", said Eric Mader,
National Pollinator<br>
Outreach Coordinator for the Xerces Society. "The Department of
Natural<br>
Resources has taken the first step in protecting these
species."<br>
><br>
> Both species were once among the most common of state's bumble
bees<br>
prior<br>
> to<br>
> the late 1990's. In a 1995 survey, over 90% of all bumble bees
collected in<br>
> the northern part of the state were the yellowbanded bumble
bee. Recent<br>
surveys have found that the yellowbanded and rusty-patched bumble
bees<br>
represent less than 1% of all bumble bees observed in the region.<br>
><br>
> "This is really a very dramatic decline", said Sarina
Jepsen, Endangered<br>
Species Coordinator for the Xerces Society and co-author of a recent<br>
status<br>
> review of the species. "The two bumble bees have declined
across the<br>
eastern<br>
> U.S. and a closely related species, the western bumble bee is<br>
experiencing<br>
> similar declines on the west coast."<br>
><br>
> This decline is especially alarming because bumble bees are
important<br>
pollinators of many native plants, as well as some of the state's<br>
high-value<br>
> agricultural crops, including cranberries. Several studies have
shown<br>
that<br>
> on a bee-for-bee basis bumble bees are several times more efficient
than<br>
honey bees for some crops.<br>
><br>
> The exact reason for the decline of these species is unclear.
The<br>
leading<br>
> theory is that one or more European bumble bee diseases were
introduced<br>
to<br>
> North America during efforts by a European company to rear
American<br>
bumble<br>
> bees for managed crop pollination in their European facility.
However,<br>
habitat loss as well as pesticide use are likely contributing
factors.<br>
The<br>
> decline of these bumble bees does not appear directly related to
similar<br>
highly publicized declines of the non-native European honey bee<br>
> (*Apis**mellifera<br>
> *).<br>
><br>
> In 2007 and 2008, isolated populations of the yellowbanded bumble
bee<br>
were<br>
> found around the towns of Mountain, Manitowish Waters, and Two
Rivers in<br>
northeastern Wisconsin. There is also a 2007 report from the<br>
UW-Milwaukee<br>
> Cedarburg Bog Field Station, in Ozaukee Co. These populations
represent the<br>
> only remaining known yellow-banded bumble bees in the Midwest. While
the<br>
rusty-patched bumble bee has not been documented in the state in
recent<br>
years, some individuals have been found in isolated areas of
Illinois.<br>
><br>
> The Status Review of Three Formerly Common Species of Bumble Bee in
the<br>
Subgenus<br>
>
Bombus<<a href="http://www.xerces.org/wp-content/uploads/2008/12/xerces_2008_bombus_status_review.pdf%3Edocuments" eudora="autourl">
http://www.xerces.org/wp-content/uploads/2008/12/xerces_2008_bombus_status_review.pdf>documents</a>
<br>
the decline of these two species throughout their native ranges in
the<br>
eastern U.S. It also includes information on the decline of the
western<br>
> bumble bee in the western U.S.<br>
><br>
> Download the report or read more about declining bumble<br>
>
bees<<a href="http://www.xerces.org/bumblebees/" eudora="autourl">
http://www.xerces.org/bumblebees/</a>><br>
>
<<a href="http://www.xerces.org/bumblebees/%3ERead" eudora="autourl">
http://www.xerces.org/bumblebees/>Read</a> about the
rusty-patched<br>
> bumble
bee<<a href="http://www.xerces.org/rusty-patched-bumble-bee/" eudora="autourl">
http://www.xerces.org/rusty-patched-bumble-bee/</a>><br>
>
<<a href="http://www.xerces.org/bumblebees/%3ERead" eudora="autourl">
http://www.xerces.org/bumblebees/>Read</a> about the yellowbanded
bumble<br>
>
bee<<a href="http://www.xerces.org/yellow-banded-bumble-bee/" eudora="autourl">
http://www.xerces.org/yellow-banded-bumble-bee/</a>><br>
><br>
> PHOTO CREDIT<br>
> The rusty-patched bumble bee (*Bombus affinis*) by Johanna
James-Heinz<br>
><br>
> ###<br>
><br>
> The Xerces Society ? 4828 SE Hawthorne Blvd. Portland, Oregon 97215
USA<br>
?<br>
> tel 503.232.6639<br>
><br>
> join
<<a href="http://www.xerces.org/join/" eudora="autourl">
http://www.xerces.org/join/</a>> ? give
<<a href="http://www.xerces.org/give/" eudora="autourl">
http://www.xerces.org/give/</a>><br>
?<br>
> contact
<<a href="http://www.xerces.org/contact-us/" eudora="autourl">
http://www.xerces.org/contact-us/</a>> <info@xerces.org> ?<br>
>
unsubscribe<<a href="http://www.xerces.org/newsletter-optout/" eudora="autourl">
http://www.xerces.org/newsletter-optout/</a>><br>
><br>
> Copyright (C) 2008 The Xerces Society. All rights reserved.<br>
> _______________________________________________<br>
> Pollinator mailing list<br>
> Pollinator@lists.sonic.net<br>
>
<a href="http://lists.sonic.net/mailman/listinfo/pollinator" eudora="autourl">
http://lists.sonic.net/mailman/listinfo/pollinator</a><br>
><br><br>
<br>
-- <br>
John S. Ascher, Ph.D.<br>
Bee Database Project Manager<br>
Division of Invertebrate Zoology<br>
American Museum of Natural History<br>
Central Park West @ 79th St.<br>
New York, NY 10024-5192<br>
work phone: 212-496-3447<br>
mobile phone: 917-407-0378<br><br>
<br><br>
<br><br>
<br>
------------------------------<br><br>
_______________________________________________<br>
Pollinator mailing list<br>
Pollinator@lists.sonic.net<br>
<a href="http://lists.sonic.net/mailman/listinfo/pollinator" eudora="autourl">
http://lists.sonic.net/mailman/listinfo/pollinator</a><br><br>
<br>
End of Pollinator Digest, Vol 364, Issue 1<br>
******************************************<br><br>
<br>
__________ Information from ESET Smart Security, version of virus
signature database 3834 (20090206) __________<br><br>
The message was checked by ESET Smart Security.<br><br>
<a href="http://www.eset.com/" eudora="autourl">http://www.eset.com</a>
</blockquote>
<x-sigsep><p></x-sigsep>
________________________________________<br>
<font size=2><b>The Xerces Society for Invertebrate Conservation<br>
</b></font><font size=1>The Xerces Society is an international, nonprofit
organization that <br>
protects wildlife through the conservation of invertebrates and their
<br>
habitat. To join the Society, make a contribution, or read about our
<br>
work, please visit <a href="http://www.xerces.org/">www.xerces.org</a>
<br><br>
Sarina Jepsen<br>
Endangered Species Coordinator<br>
4828 SE Hawthorne Blvd. Portland, OR 97215<br>
tel: 503-232-6639 fax: 503-233-6794<br>
email: sarina@xerces.org<br>
</font>________________________________________<br>
</body>
</html>