They have been spotted in Wisconsin; I collected 7 eggs this morning. Hang in there, they're on their way:)

Thanks, Leafhead. I'll be patient and keep checking the milkweeds for eggs. I remember it took a few years for the Monarchs to find my other butterfly gardens, and this will be the first year I have a significant volume of milkweed for them. I'm counting on the wild field of common milkweed down the street to provide me with eggs and cats. I'll keep checking.

Martha

This is a theory that I worked on a couple of years back based on the cardenolide content of various species of asclepias, and past studies and research on that as well as latex content. This is only theoretical, but it seems normal Monarch's of course will prefer a native asclepias in the Ohio/Mich area, which is usually always the native a. incarnata over a. syriaca, due to the fact common milkweed has a higher latex content, (which cats have a way to avoid by a specific chewing pattern, but if they can get less latex to start with they seem to prefer that). I say "normal", because there is also a good percentage of Monarch's that are infected with parasites that have offspring this is passed onto. There was a study done by an evolutionary biologist at Emory University down in Atlanta that seemed to determine that Monarch's that are infected have a unique ability to "self-medicate", and lay eggs on milkweed with the highest level of cardenolides, which would be tropical milkweed (a. curassivica), and this may have a protective anti-parasitic action, in addition to the other protective action the toxins give them. Also, MonarchWatch Organization has compared 14 different species of asclepias and determined the "best" was a. curassivica, although in the south where it can grow as a perennial there have been some issues with O.E.
So basically it seems that a good combo to have growing to induce the greatest egg laying activity, are both a. incarnata and a. curassivica (as an annual here, obviously), and the plant that has the greatest ability to attract nectaring Monarch's is Liatris ligulastylis (Meadow Blazing Star) due to a yet undetermined chemical signal that nothing else seems to have that is specific to Monarch's. I would call it the catnip for Monarch's, it is pretty amazing (almost bizarre). True that neither tropical milkweed or L. ligulastylis are native here, but we are talking about helping to population boost. Both are in fact native species that Monarch's do come across in their travels normally. So the ultimate Monarch Trilogy to have would be swamp and tropical milkweeds, and Meadow Blazing Star, and of course as many other natives of the local genotype as possible, with native New England Aster in the fall to help fuel them for migration.

KSOhio,
You just made my day. I have my first 4 A. Curassavica plants this year. I winter sowed several Liatris ligulastylis last year, which should bloom this summer. And I've had A. Incarnata and New England Aster for years. I also planted tons of zinnias and many perennials that should keep the nectaring butterflies happy. I hope I'm able to give quite a few Monarchs a helping hand.

Martha