next message in archive
no next message in thread
previous message in archive
Index of Subjects
Hi Steve & All, Oct 7, 2015 My Merck is 1976 so a bit dated but Cantharides has been around a long time. But the Merck information is ambiguous and 1 mg/kg for horses sounds far-fetched so where does the truth really lie ? [When the truth lies is self-evident; election time]. If a horse died from eating a 'Blister Beetle' how could one establish that it had eaten a Blister Beetle ? So I suspect Baron Munchausen, or an understudy, was involved in that one. Yt, DW, Kentville ----- Original Message ----- From: "Stephen Shaw" <srshaw@Dal.Ca> To: <natureNS@chebucto.ns.ca> Sent: Wednesday, October 07, 2015 1:44 AM Subject: [NatureNS] RE: [New post] Blister Beetles’ Defense Mechanism > Hi Dave et al, > Curious also, I checked cantharidin on Wikipedia, recalling having read > somewhere that an entire French Foreign Legion outpost was reputedly > immobilised, so to speak, from painful priapism of many hours duration > from ingesting the stuff as Spanish Fly, intended as an aphrodisiac. The > LD(50) (the lethal dose estimated to kill 50% of those receiving it) is > cited as 0.5mg/kg for humans, so for a modest 50kg/110 lb human, LD(50) > would be 25 mg, but the text says that as little as 10 mg 'can be lethal' > (or 'has been lethal'? - otherwise how would you know?). Some blister > beetle species (Epicauta) are said to contain nearly 5 mg each, so > grinding up and ingesting an extract from as few as 2-5 such beetles could > do you in. > > For horses, 1 mg/kg is quoted. Apparently, a few beetles hiding in bales > of feed hay have made short work of some horses. > > Depending on whether it's a recent edition, one would normally rate the > Merck Index above Wikipedia for reliable numbers, otherwise perhaps vice > versa for some substances. > Steve (Hfx) > ________________________________________ > From: David & Alison Webster [dwebster@glinx.com] > Sent: Monday, October 5, 2015 8:59 PM > To: Jim Wolford; Ian Manning > Cc: Chris Majka; David McCorquodale; Angus MacLean; Stephen Shaw > Subject: Re: [New post] Blister Beetles’ Defense Mechanism > > Hi All, > I just noticed that this was not on Naturens so my reply a few minutes > ago, effectively to Jim only, is pasted below. > START OF PASTE\\\\\ > I wouldn't bet the farm on this being a balanced account. > > According to my Merck Index 9th ed., the subcutaneous LD in rabbits of > cantharidin is 100 mg/Kg. Cantharides (Spanish Fly), derived from > Cantharis vesicatoria [really Lytta vesicatoria DW], is stated to contain > 0.6-1% cantharidin and to be highly toxic to humans by ingestion or > absorption from skin or mucous membranes. > > I wonder if the reference, in this Naturally Curious article, to 100 mg > being lethal to humans, originated in the 100 mg/Kg sc lethal dose of > rabbits. > YT, DW, Kentville > END OF PASTE > ----- Original Message ----- > From: Jim Wolford<mailto:jimwolford@eastlink.ca> > To: Ian Manning<mailto:ianmanning4@gmail.com> > Cc: Chris Majka<mailto:c.majka@ns.sympatico.ca> ; David > McCorquodale<mailto:david_mccorquodale@cbu.ca> ; Angus > MacLean<mailto:angusmcl@ns.sympatico.ca> ; Stephen > Shaw<mailto:srshaw@dal.ca> ; David & Alison > Webster<mailto:dwebster@glinx.com> > Sent: Monday, October 05, 2015 6:04 PM > Subject: Re: [New post] Blister Beetles’ Defense Mechanism > > Thanks, Ian! OK to disseminate more widely? > > On Oct 5, 2015, at 8:57 AM, Ian Manning > <ianmanning4@gmail.com<mailto:ianmanning4@gmail.com>> wrote: > > Another bite of cool natural history from Mary Holland. > > Cheers, > Ian > > ---------- Forwarded message ---------- > From: Naturally Curious with Mary Holland > <comment-reply@wordpress.com<mailto:comment-reply@wordpress.com>> > Date: 5 October 2015 at 08:03 > Subject: [New post] Blister Beetles’ Defense Mechanism > To: imanning@upei.ca<mailto:imanning@upei.ca> > > > Mary Holland posted: "Blister beetles are aptly named, for when they are > disturbed they emit a yellow, oily, defensive secretion (cantharidin) from > their joints which usually causes blisters when it comes in contact with > skin. This toxin deters many potential predators and is " > Respond to this post by replying above this line > > New post on Naturally Curious with Mary Holland > > [http://0.gravatar.com/blavatar/247bf460fa81e5a816e31c38c1012308?s=32&d=http%3A%2F%2Fs0.wp.com%2Fi%2Femails%2Fblavatar.png&ts=1444043068] > [http://2.gravatar.com/avatar/2f68fa0a2118c80811a23d5613ffacbc?s=50&d=identicon&r=G]<https://naturallycuriouswithmaryholland.wordpress.com/author/naturallycuriouswithmaryholland/> > Blister Beetles’ Defense > Mechanism<https://naturallycuriouswithmaryholland.wordpress.com/2015/10/05/blister-beetles-defense-mechanism/> > by Mary > Holland<https://naturallycuriouswithmaryholland.wordpress.com/author/naturallycuriouswithmaryholland/> > > [10-5 short-winged blister beetle > 064]<https://naturallycuriouswithmaryholland.files.wordpress.com/2015/10/10-5-short-winged-blister-beetle-0641.jpg>Blister > beetles are aptly named, for when they are disturbed they emit a yellow, > oily, defensive secretion (cantharidin) from their joints which usually > causes blisters when it comes in contact with skin. This toxin deters many > potential predators and is especially effective against ants. According to > naturalist/forester/writer Ginny Barlow, as little as 100 milligrams is > reported to be fatal to humans if ingested, and this amount can be > extracted from just a few beetles. Humans used to crush and dry blister > beetles and use the resulting concoction for gout and arthritis. It was > also used as a popular aphrodisiac known as Spanish fly. Because of its > toxicity, it is no longer widely used in medicine. > > Cantharidin is, however, indirectly used by tree-nesting nuthatches. With > a limited number of tree cavities, there is competition among animals > using them to raise their young, especially between squirrels and > nuthatches. Nuthatches have been seen with Short-winged Blister Beetles > (Meloe angusticollis, see photo) in their beaks, "sweeping" them on the > bark around tree cavity entrances. The nuthatches don’t eat the beetles, > they strictly use them as tools. It is assumed that the birds do this in > order to repel squirrels with the cantharidin that is smeared on the tree. > (Thanks to Ginny Barlow for photo opportunity.) > > Naturally Curious is supported by donations. If you choose to contribute, > you may go to > http://www.naturallycuriouswithmaryholland.wordpress.com<http://www.naturallycuriouswithmaryholland.wordpress.com/> > and click on the yellow “donate” button. > > Mary > Holland<https://naturallycuriouswithmaryholland.wordpress.com/author/naturallycuriouswithmaryholland/> > | October 5, 2015 at 7:01 am | Tags: > Cantharidin<https://naturallycuriouswithmaryholland.wordpress.com/tag/cantharidin/>, > Meloe > angusticollis<https://naturallycuriouswithmaryholland.wordpress.com/tag/meloe-angusticollis/> > | Categories: > Beetles<https://naturallycuriouswithmaryholland.wordpress.com/category/beetles/>, > Defense > Mechanisms<https://naturallycuriouswithmaryholland.wordpress.com/category/defense-mechanisms/>, > Insects<https://naturallycuriouswithmaryholland.wordpress.com/category/insects/>, > October<https://naturallycuriouswithmaryholland.wordpress.com/category/october/>, > Short-winged Blister > Beetle<https://naturallycuriouswithmaryholland.wordpress.com/category/short-winged-blister-beetle/>, > Uncategorized<https://naturallycuriouswithmaryholland.wordpress.com/category/uncategorized/> > | URL: http://wp.me/pNTN1-35w > > Comment<https://naturallycuriouswithmaryholland.wordpress.com/2015/10/05/blister-beetles-defense-mechanism/#respond> > See all > comments<https://naturallycuriouswithmaryholland.wordpress.com/2015/10/05/blister-beetles-defense-mechanism/#comments> > > > > > Unsubscribe<https://subscribe.wordpress.com/?key=519298e3b6673bffa02d15c276347b44&email=imanning%40upei.ca&b=LLh6Efu%2C%2Fj9F6%5B%5Bqi0Q%3D%26qSjEu%3DCkN%2F%5DocaxRLCe%2B2SPd5M%5D.l> > to no longer receive posts from Naturally Curious with Mary Holland. > Change your email settings at Manage > Subscriptions<https://subscribe.wordpress.com/?key=519298e3b6673bffa02d15c276347b44&email=imanning%40upei.ca>. > > Trouble clicking? Copy and paste this URL into your browser: > https://naturallycuriouswithmaryholland.wordpress.com/2015/10/05/blister-beetles-defense-mechanism/ > > > > > Thanks for flying with [http://s.wordpress.com/i/emails/wp-footericon.png] > WordPress.com<http://wordpress.com/> > > > > > > > No virus found in this message. > Checked by AVG - www.avg.com<http://www.avg.com> > Version: 2015.0.6140 / Virus Database: 4435/10762 - Release Date: 10/05/15 > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2015.0.6140 / Virus Database: 4435/10768 - Release Date: 10/06/15 >
next message in archive
no next message in thread
previous message in archive
Index of Subjects