Using Citizen Science Data to Explore Immature Monarch Presence on Different Milkweed Species
Category: Oral Presentation
Author(s): CeLee Terasa
Presenter(s): CeLee Terasa
Mentors(s): John Mola, Laura Lukens
Monarch butterflies (Danaus plexippus), an iconic insect pollinator, are declining due to climate change and habitat loss. Their larvae exclusively feed on milkweed (Asclepias) host plants, sequestering toxic cardiac glycosides for defense against predators and parasites. With monarchs recorded on 73 milkweed species in our dataset, we ask: Are immature monarchs more likely to be present on certain species, and does this differ between native and non-native milkweeds? Furthermore, how do spatial or temporal patterns influence monarch presence? While lab studies have tested monarch preference for a few milkweed species, large-scale field investigations remain scarce. To address this knowledge gap, we analyzed 15 years of citizen science data from the Monarch Larva Monitoring Project (MLMP) and the Integrated Monarch Monitoring Program (IMMP), spanning the contiguous U.S. We hypothesize that immature monarch presence varies by milkweed species, region, and season. Preliminary results of our study suggest that A. curassavica, a non-native species, harbors far more monarch eggs and larvae than native species. Meanwhile, we are continuing to analyze spatial and seasonal patterns using GIS applications to better understand regional variation in milkweed species related to monarch presence. As non-native milkweeds become more widespread, further research is needed to determine factors driving monarch presence for these species and their potential effects on survival, fitness, and population dynamics. These findings can inform conservation efforts by identifying milkweed species that best support monarchs across different regions and assessing the ecological implications of non-native milkweed in both natural and urban landscapes.