Milkweed- Research Tanner Douglas Cole

Danaus plexippus (Monarch butterfly): Monarch Lifecycle summary  Females lay about 400 to 1200 eggs in her 4 week life span  Eggs hatch after 4 days  Goes through several instar stages over a 2 week period before it starts forming its chrysalis  11 days later, the chrysalis splits and the butterfly immerges -Total time elapsed 29-30 days -During the summer, the butterflies don’t migrate since there is still a food source for their caterpillars. Once the food source starts to decline, they migrate to Mexico to overwinter and return the following year.

Asclepias curassavica (Tropical milkweed):

http://www.mgonlinestore.com/milkweed/ http://plants.usda.gov/core/profile?symbol=ASCU

Perhaps the most ornamentally attractive in the genus, tropical milkweed is native to South America and has been introduced into several southern states. It can also be grown as an annual in the North. The research that has been completed on this plant is somewhat multifaceted. One of the reasons why researchers don’t want people to plant tropical milkweed has to do with a disease that cripples monarchs and prevents them from developing properly. The pathogen (Ophryocystis elektroscirrha) can build up on that grow year round (IE without a dieback period), like those in the south. It’s suggested that if you’re growing this plant in the south, you cut it back about the same time as the native milkweeds senesce as to reduce the amount of inoculum capable of infecting the monarchs. Since there hasn’t been much research covering this plant’s effect on monarch populations in the North, I would suggest cutting this plant back the same time the native milkweed (Asclepias syriaca) goes dormant as to not negatively affect the monarchs lifecycle. With that being said, I have a feeling that the tropical milkweed will die about the same time our native milkweed goes dormant. However, cutting this milkweed back might not be enough to discourage monarchs from reproducing too late. We understand so little of what goes on in the selection process; there might be biochemical signs exuded from native milkweeds that tropical milkweeds simply don’t bother producing. In short, in the North, we don’t need to worry about the Ophryocystis elektroscirrha pathogen but we should be mildly concerned with the plant surviving too late in the season and forcing monarchs to continue breeding later than what is optimal. Milkweed-Monarch Butterfly Research Tanner Douglas Cole

Asclepias syriaca (native milkweed/common milkweed):

http://plants.usda.gov/core/profile?symbol=ASSY http://www.amazilia.net/images/Plants/Flowering_Plants/Asclepias_syriaca_1870.jpg

The widespread and continuous use of herbicides has caused this plant’s natural populations to drop over 90%. Seeds are relatively cheap for this (1000 for $3.20) and could be propagated in the greenhouse for the upcoming plant sale. It has the potential to be slightly aggressive but I think we could simply tell people that fact and let them weigh the pros and cons of planting it. Despite the fact that tropical milkweed MIGHT be fine to plant in the Midwest, I still feel more comfortable using native species, if it evolved here, it belongs here.

Milkweed-Monarch Butterfly Research Tanner Douglas Cole

Cynanchum laeve (Vining milkweed/honeyvine milkweed):

http://stlwildones.org/monarchs-prefer-this-inconvenient-vine-in-my- http://plants.usda.gov/core/profile?symbol=CYL yard/ A

Though somewhat ugly (as it resembles the infamous bindweed), the vining milkweed is an extremely fast growing vine that is native to the Eastern and Midwestern United States. This means that its effect on the monarch lifecycle is nearly identical to that of our common milkweed. It seems to be preferred by monarchs compared to any of the other milkweeds (though this is somewhat anecdotal) including common milkweed, tropical milkweed, swamp milkweed and butterfly weed. The others are all in the Asclepias genus though the vining milkweed is in the same family as the others, . I don’t think we should promote growing this in people’s home gardens because it can be somewhat aggressive. However, I absolutely think that we should keep it in the area by the loading dock with the Verbena bonariensis (purpletop vervain) because it’s a moderately tough site with all of that reflected heat from the parking lot, it’s already there, the dual relationship is attractive in my opinion, it’s isolated from spreading out of control, and it acts like a monarch hatchery. As long as we include some kind of sign with a description of the site and a clarification about the vine, we should be golden. This type of sign, including the support structure, will probably only cost us around $100-$120, AKA a lot cheaper than planting all new plants.

Whether or not we should plant tropical milkweed in the Midwest: It can be done, but it requires diligence (IE cutting back the tropical milkweed when the native one goes dormant). It might be a smart idea to grow the two side by side to see how both of them interact with monarchs and to see which one dies/goes dormant first in the autumn. However, in the grand scheme of things, I believe that there are equally ornamental native milkweed options out there that we should consider as more permanent alternatives. Milkweed-Monarch Butterfly Research Tanner Douglas Cole

Other Milkweeds include:  (Butterfly weed): Native that could possibly serve as a midway point between the tropical milkweed and our native milkweed. It prefers well drained sites; 550 seeds for $7.50.

http://plants.usda.gov/core/profile?symbol=astu http://delawarewildflowers.org/images/010624_083640.jpg

 Asclepias lanceolata (Lanceolate milkweed/fewflower milkweed): I wouldn’t suggest this one for cultivation.

http://plants.usda.gov/core/profile?symbol=asla2

https://en.wikipedia.org/wiki/Asclepias_lanceolata# mediaviewer/File:Asclepias_lanceolata_plant.jpg

Milkweed-Monarch Butterfly Research Tanner Douglas Cole

 Asclepias incarnata (Swamp Milkweed): As the name implies, it prefers wet sites with moisture retaining soil.

http://www.minnesotawildflowers.info/flower/swamp-milkweed http://plants.usda.gov/core/profile?symbol=ASIN

http://www.minnesotawildflowers.info/flower/swamp- Sources:milkweed 1. Butterfly weed description (Wikipedia): https://en.wikipedia.org/wiki/Asclepias_tuberosa 2. Monarch butterfly description (Wikipedia): http://en.wikipedia.org/wiki/Monarch_butterfly 3. Monarch lifecycle: http://basrelief.org/Pages/monarchs.html 4. Native milkweed description (Wikipedia) : https://en.wikipedia.org/wiki/Asclepias_syriaca 5. Original article: http://www.nytimes.com/2014/11/18/science/monarchs-may-be-loved-to- death.html?_r=0 6. Prairie moon nursery Asclepias syriaca: https://www.prairiemoon.com/seeds/wildflowers- forbs/asclepias-syriaca-common-milkweed.html 7. Prairie moon nursery Asclepias tuberosa: https://www.prairiemoon.com/seeds/wildflowers- forbs/asclepias-tuberosa-butterfly-weed.html 8. Risks of growing tropical milkweed factsheet: http://monarchjointventure.org/images/uploads/documents/Oe_fact_sheet.pdf 9. To plant or not to plant article: http://texasbutterflyranch.com/2013/02/25/tropical-milkweed-to- plant-it-or-not-its-not-a-simple-question/ 10. Tropical milkweed description: http://nababutterfly.com/tropical-milkweed/ 11. Tropical milkweed description (Wikipedia): http://en.wikipedia.org/wiki/Asclepias_curassavica 12. Vining Milkweed/ Honeyvine milkweed description (Wikipedia): https://en.wikipedia.org/wiki/Cynanchum_laeve 13. Vining milkweed/Honeyvine milkweed Dave’s garden: http://davesgarden.com/guides/articles/view/2911/#b 14. Vining milkweed/Honeyvine milkweed range: http://plants.usda.gov/core/profile?symbol=CYLA 15. Vining milkweed preferred by monarchs: http://stlwildones.org/monarchs-prefer-this- inconvenient-vine-in-my-yard/