<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<h2 class="article-title">Controversial pesticides threaten not just
bees, but butterflies, too <span class="article-meta"><span
class="article-date">August 17, 2016</span><span
class="article-category"></span></span></h2>
<h2 class="article-title"><span class="article-meta"><span
class="article-category"><a
href="http://conservationmagazine.org/conservation-science-news/"
rel="category tag">Conservation This Week</a></span> </span></h2>
<div class="pf-content">
<p>Most of the furor surrounding neonicotinoids, the world’s most
widely-used pesticides, focuses on the harms they cause to bees.
Yet these chemicals may also pose a threat—presently
little-appreciated but possibly grave—to butterflies.</p>
<p>In <a href="http://dx.doi.org/10.1098/rsbl.2016.0475"
target="_blank">a study published in the journal <em>Biology
Letters</em></a>, researchers led by biologist Matthew
Forister of the University of Nevada tracked butterfly
populations across four decades in three Northern California
counties. Butterflies there face many challenges, including
climate change, drought, and habitat loss to agriculture and
urban sprawl. Yet even with those factors accounted for,
neonicotinoids seem to pose a unique <span class="s1">threat:
the researchers found that declines in butterfly health and
reproductive success accelerated dramatically after the
pesticides entered widespread use in the mid-1990s.</span></p>
<p>There are caveats to the study, stress the researchers. “The
evidence is correlational,” cautions study co-author Art
Shapiro, an ecologist at the University of California, Davis,
who started monitoring the region’s butterflies in 1972. “That’s
not the same thing as proving causation.”</p>
<p>If not definitive, though, the findings do dovetail with
similar results from a long-term, large-scale study of butterfly
populations in Great Britain. They also fit with what’s known
about the toxicity of neonicotinoids to insects and the
chemicals’ ubiquitous environmental presence due to runoff from
agricultural fields and urban landscaping. There might not be
fire, but there’s certainly a lot of smoke.</p>
<p>Public concern about neonicotinoids and bees has prompted the
Environmental Protection Agency to review their safety, and some
municipalities have restricted their use. While awaiting further
research and regulation, one wonders: what might become of a
world with fewer butterflies?</p>
<p>“We don’t know,” says Shapiro. “For this area, at least, the
sky has not fallen.” Then again, it’s only been an ecological
eyeblink since the butterfly declines started. The effects may
take many more decades to become obvious. Perhaps there would be
fewer of the plants that butterflies pollinate, and fewer of the
animals who feed on them. If nothing else, there would be a lot
less beauty in the world. <strong>—Brandon Keim | 17 August
2016</strong></p>
<p><strong>Source:</strong> Forister et al. Increasing
neonicotinoid use and the declining butterfly fauna of lowland
California. <em>Biology Letters,</em> 2016. doi:
10.1098/rsbl.2016.0475</p>
</div>
<div class="section abstract" id="abstract-1">
<h2>Abstract</h2>
<p id="p-2">The butterfly fauna of lowland Northern California has
exhibited a marked decline in recent years that previous studies
have attributed in part to altered climatic conditions and
changes in land use. Here, we ask if a shift in insecticide use
towards neonicotinoids is associated with butterfly declines at
four sites in the region that have been monitored for four
decades. A negative association between butterfly populations
and increasing neonicotinoid application is detectable while
controlling for land use and other factors, and appears to be
more severe for smaller-bodied species. These results suggest
that neonicotinoids could influence non-target insect
populations occurring in proximity to application locations, and
highlights the need for mechanistic work to complement long-term
observational data.</p>
</div>
<br>
<pre class="moz-signature" cols="72">--
Dr. David W. Inouye
Professor Emeritus
Department of Biology
University of Maryland
College Park, MD 20742-4415
<a class="moz-txt-link-abbreviated" href="mailto:inouye@umd.edu">inouye@umd.edu</a>
Principal Investigator
Rocky Mountain Biological Laboratory
PO Box 519
Crested Butte, CO 81224</pre>
</body>
</html>