—Jim Armbruster, Research Coordinator
As monarchs slowly return to Vermont, reports of observations are starting to come in throughout the state. With sightings all around it was only a matter of time before they returned to our campus meadow. The last two years we have been keeping track of their summer return. In the summer of 2019 the first sighting of a lone butterfly was on 6/8. This year the first two were spotted today, the 15th of July! Several eggs were also observed on milkweeds throughout campus. After a great summer last year for monarchs, the overwintering populations were actually down slightly from the previous year. We are waiting to see what this summer will bring for monarch populations on campus.
Another aspect of our monarch monitoring involves a health check up for the butterflies for Project Monarch Health through the University of Georgia. “It is a citizen science project in which volunteers sample wild monarch butterflies to help track the spread of a protozoan parasite across North America.” –Monarch Health. This involves sampling for Ophryocystis elektroscirrha (OE) a parasite that infects monarch and other species of butterflies. OE is a single celled protozoan that can be found on the butterflies. When not living in a host, it survives as spores that can be collected from the butterflies’ abdomen using a clear sticker. Once the sample is collected, the butterfly is marked and released. The collected samples are then sent to the lab at the University of Georgia. Last year we sampled 60 butterflies and recently received the results. Of the samples we sent in, four had heavy OE spore loads. This means that over 100 spores were found when looking at the sample under a microscope.
So what does that mean for our monarchs? OE can cause a monarch chrysalis to fail and not produce a butterfly. Because of this, the spores have the potential to negatively impact the populations of monarchs but do not seem to have an effect on the adults. “Infected adults emerge covered with spores. Once butterflies are infected, they do not recover. By the time adults emerge with parasite spores, all physical damage by the OE parasites has been done – the parasites do not grow or reproduce on the adults.” –Monarch Health. The eastern migratory population of monarchs has the lowest rate of infection with about 8% found with spores. This project is just one more way to help protect the monarch butterfly and is another long term data set that we can generate here on our campus.
To learn more about Monarch Health click here!