Regarding the current study we will be participating in this fall/winter. We will not be cutting down the tropical milkweed at the Sparrow Field, but will let it grow and test monarchs present and breeding on it for OE parasite. Meanwhile, at our sister site Wormsloe, UGA grad student Ania Majewska, will cut down the tropical milkweed and test any monarch present. This comparison will give us a clearer understanding as to whether tropical milkweed is truly a cause of increased parasite infestation, or not. But we still highly recommend home gardeners cut their tropical milkweeds back October through March.
Fitz Clarke Photogapher
The data are in and the findings are not good. In her newly published research paper Dara Satterfield, PhD student at UGA found that Monarchs are infected with the OE (Ophryocystis elektroscirrha) parasite at a rate 5- 9 times higher when they interrupt their migration compared to Monarchs who continue on their journey. The thinking is that non-native tropical milkweed growing all winter encourages the Monarchs to halt their migration to breed and overwinter. Migration is beneficial to the butterfly population because it weeds out weak and sick individuals and also removes them from the infected habitat.
In response to these findings Satterfield and her team have developed the next phase of the study. She has asked the volunteers at the Sparrow Field to cut the non-native tropical milkweed (asclepias curassavica) down to the ground and keep it cut down until sometime in March. This will prevent the butterflies from stopping to breed and lay eggs on tropical milkweed foliage during the winter. When the butterflies return next spring we will again test for OE parasites to determine whether there is any change in infection rates at the Sparrow Field. The volunteers are working this spring to grow 5 native milkweed species from seed to be planted at the Sparrow Field.
What can YOU do in your own garden? The study team has the following suggestions:
1) Plant native milkweeds. They naturally die back each fall, and regrow at the time the Monarch returns.
2) If you have tropical milkweed cut it down from October to March. And remove any sprouted leaves at the base of the plant.
3) Gradually replace your tropical milkweed with native species.
4) Learn to identify and protect native milkweeds.
5) Ask local growers to produce native milkweeds.
While the OE problem may not cause the extinction of Monarchs by itself, it could be a serious detriment to
their survival if the population continues to decline as it has in the last several years. Concerned and educated
gardeners will be a large part of the solution to the problems faced by our iconic Monarch butterflies. We hope
the Monarch will be around to be enjoyed for generations to come.
Sue Hamlet, Sparrow Field Co-chair
Why Tag Monarchs?
"Many questions remain unanswered about the fall migration of the monarch population east of the Rocky Mountains.
How do the monarchs move across the continent, i.e. do they move in specific directions or take certain pathways?
How is the migration influenced by the weather and are there differences in the migration from year to year?
We need data to answer these questions and we need your help! Only through the cooperative efforts of volunteer taggers will we be able to obtain sufficient recoveries and observations of the migration to answer these questions.
Through participation in this project we hope to further interest in the conservation of habitats critical to the survival of the monarch butterfly and its magnificent migrations." - Monarchwatch.org
Releasing ladybug beetles to reduce aphid infestation on milkweed
Releasing a butterfly
Preparing to release Sparrow Field monarchs raised in lab at UGA
Sampling monarch butterflies as part of UGA's Monarch Health research
- The Monarch Relay
- "A monarch flies south with the first cold snap, resting along the way, until it finds a sheltered, warm place to spend the winter.
- In spring, it migrates northward, stopping to drink from the emerging flowers, mate, lay eggs and then die, having lived for a total of 7-8 months.
- The new monarchs that emerge from these eggs fly north as well, but only travel a relatively few miles.
- They mate, lay eggs and die, having lived for about one month.
- Their eggs emerge and repeat the one-month lifespan. Up to five generational waves continue north until the weather signals the return." - The Nature Conservatory
Want to help Monarchs by planting milkweed? Be sure it's the right type or you will be doing more harm than good.