next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects
pan></div><br><div> --============_-800641577==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" At 9:54 AM -0300 9/23/14, Jim Wolford wrote: >THANKS, KIRK, from Jim in Wolfville > >>From: Kirk Hillier <<mailto:kirk.hillier@acadiau.ca>kirk.hillier@acadiau.ca> >>Subject: Re: complexity of mimicry examples -- was Batesian Mimic - got me >>Date: September 22, 2014 at 8:47:48 PM ADT >>To: Jim Wolford >><<mailto:jimwolford@eastlink.ca>jimwolford@eastlink.ca>, naturens >><<mailto:naturens@chebucto.ns.ca>naturens@chebucto.ns.ca> >>Cc: Todd Smith <<mailto:todd.smith@acadiau.ca>todd.smith@acadiau.ca> >> >>My understanding is that all milkweed species will produce the >>cardiac glycosides which make them (and subsequently monarchs) >>distasteful or even toxic. The amount produced by each species is >>undoubtedly variable. It is worth noting that monarchs will feed >>on a Physocarpus ('nine bark') species as well - I'd wager they're >>less toxic/non toxic under those circumstances. The queen >>butterflies also sequester similar compounds from their food plants. I beg to differ with this "worth noting" statement. There are no records, that I am aware of, of Danaus plexippus feeding on any member of the Rosaceae (see the HOSTS database at http://www.nhm.ac.uk/research-curation/research/projects/hostplants/). I suspect this erroneous 'record' of Physocarpus opulifolius (ninebark) is actually an error derived from the Monarch's known use of Gomphocarpus physocarpus, a member of the Asclepiadaceae (the milkweed family). On the subject of Asclepias phytochemistry, there IS variation in the quantity, efficacy and identity of cardenolides found amongst, and even within, species of milkweeds (see http://onlinelibrary.wiley.com/enhanced/doi/10.1111/j.1469-8137.2011.04049.x/ for the excellent recent review by Agrawal et al., 2012). There is also variation in the use and preference of Monarch butterflies for these plants (only 27 of the 108 known species of milkweed in North America are used by Monarchs, Malcolm & Brower, 1989, Experentia, citation below). As has been noted the common milkweeds found in NS have relatively low cardenolide levels, however, it is important to note that these levels are significantly higher in the young plants that are overwhelmingly preferred by Monarchs AND that caterpillars can bioaccumulate cardenolides to concentrations much higher than is present in the milkweeds that they feed on (see Malcolm and Browers 1989 paper in Experentia, full text at http://link.springer.com/article/10.1007%2FBF01951814#page-1). Phil -- Phil Schappert, PhD 27 Clovis Ave. Halifax, NS, B3P 1J3 902-460-8343 (cell) philschappert.ca imaginaturestudio.ca imaginaturestudio.blogspot.ca philschappert.com "Just let imagination lead, reality will follow through..." (Michael Hedges) --============_-800641577==_ma============ Content-Type: text/html; charset="us-ascii" <!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"><!-- blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 } --></style><title>Re: [NatureNS] re complexity of mimicry systems</title></head><body> <div>At 9:54 AM -0300 9/23/14, Jim Wolford wrote:</div> <blockquote type="cite" cite>THANKS, KIRK, from Jim in Wolfville<br> <blockquote type="cite" cite><b>From:</b> Kirk Hillier <<a href="mailto:kirk.hillier@acadiau.ca">kirk.hillier@acadiau.ca</a >></blockquote> <blockquote type="cite" cite><b>Subject: Re: complexity of mimicry examples -- was Batesian Mimic - got me</b></blockquote> <blockquote type="cite" cite><b>Date:</b> September 22, 2014 at 8:47:48 PM ADT</blockquote> <blockquote type="cite" cite><b>To:</b> Jim Wolford <<a href="mailto:jimwolford@eastlink.ca">jimwolford@eastlink.ca</a>>, naturens <<a href="mailto:naturens@chebucto.ns.ca">naturens@chebucto.ns.ca</a >></blockquote> <blockquote type="cite" cite><b>Cc:</b> Todd Smith <<a href="mailto:todd.smith@acadiau.ca">todd.smith@acadiau.ca</a>></blockquote > <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>My understanding is that all milkweed species will produce the cardiac glycosides which make them (and subsequently monarchs) distasteful or even toxic. The amount produced by each species is undoubtedly variable. It is worth noting that monarchs will feed on a Physocarpus ('nine bark') species as well - I'd wager they're less toxic/non toxic under those circumstances. The queen butterflies also sequester similar compounds from their food plants.</blockquote> </blockquote> <div><br></div> <div>I beg to differ with this "worth noting" statement. There are no records, that I am aware of, of Danaus plexippus feeding on any member of the Rosaceae (see the HOSTS database at http://www.nhm.ac.uk/research-curation/research/projects/hostplants/). I suspect this erroneous 'record' of Physocarpus opulifolius (ninebark) is actually an error derived from the Monarch's known use of Gomphocarpus physocarpus, a member of the Asclepiadaceae (the milkweed family).</div> <div><br></div> <div>On the subject of Asclepias phytochemistry, there IS variation in the quantity, efficacy and identity of cardenolides found amongst, and even within, species of milkweeds (see http://onlinelibrary.wiley.com/enhanced/doi/10.1111/j.1469-8137.2011.<span ></span>04049.x/ for the excellent recent review by Agrawal et al., 2012). There is also variation in the use and preference of Monarch butterflies for these plants (only 27 of the 108 known species of milkweed in North America are used by Monarchs, Malcolm & Brower, 1989, Experentia, citation below).</div> <div><br></div> <div>As has been noted the common milkweeds found in NS have relatively low cardenolide levels, however, it is important to note that these levels are significantly higher in the young plants that are overwhelmingly preferred by Monarchs AND that caterpillars can bioaccumulate cardenolides to concentrations much higher than is present in the milkweeds that they feed on (see Malcolm and Browers 1989 paper in Experentia, full text at http://link.springer.com/article/10.1007%2FBF01951814#page-1).</div> <div><br></div> <div>Phil</div> <div><br></div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Courier" color="#000000"><br> Phil Schappert, PhD</font&g