Dear Forum members I work on the migration of the monarch butterfly, Danaus plexippus. I use Thin Layer Chromatography (TLC) to determine the larvae butterfly host plant. We recently found a monarch coming from Manitoba that probably fed on Asclepias asperula as a larvae. This butterfly hatched in Manitoba (we used stable isotopes to determine this) and I later caught it in Cuba (!). Amazing trip. I am sending one paper in case that you are interested (see attachment). However, we are puzzled about this result because this Asclepias sp. "only" grows in US but not in Canada. However, we found that this species is popular with some Canadian gardeners as a way to attract butterflies, including the monarch butterfly.Does anyone have, please, any records of this species in Manitoba and/or any other part in Canada? if yes, can you tell me where and when this species was observed. thanks and all the best in this festive season Cristina Dockx
Interesting work. May I ask how many species of Asclepias you've sampled for markers? There are more Asclepias spp. in Manitoba than just Asclepias syriaca -- I'm just wondering if a perhaps unsampled species has very similar markers to Asclepias asperula. If, however, you are certain it is Asclepias asperula then I suggest a few options (unless a Manitoban gardener pipes up on these forums and says that he/she grows it): 1) contact the Manitoba Master Gardener Association and see if you can get something put in one of their newsletters: http://www.mgmanitoba.com/ 2) Manitoba Home and Gardener Magazine may have a letters to the editor section 3) Dr. Diana Robson at the Manitoba Museum of Man and Nature may also be able to help: drobson at manitobamuseum dot ca
Thanks for your reply and suggestions. About how many Asclepias species has been been fingerprinted using TLC, I do not know the exact number but I will say around 34 species. Let me explain why I can only give an estimate. Many of these species were fingerprinted in the 80 when the technique was still being standarized. So, sadly it is not very useful and some of the fingerprint were not published. So, I will say you have around 13 solid fingerprints that can be used. The good news is that these are the figerprints of Asclepias that the monarchs use the most. And yes, you are right. It is possible that there is an Ascleias sp. with very similar TLC fingerprint to A.asperula that we do not know. However, there are not two Asplepias sp. with identical TLC fingerprint that we know. I will write to the people that you suggested, thanks. Anyone else that knows Asclepias in Canada? Thanks Cristina Dockx
