This week, Holden Forest and Gardens’ Conservation and Research teams collaborated to host a volunteer training for spotting the new-to-North America garlic mustard aphid. This aphid was first seen by Conservation Biologist Rebecah Troutman while she was managing garlic mustard (the invasive plant Alliaria petiolata) in Holden’s natural areas. Not sure what kind of insect it was at first, Rebecah sent a sample of the aphid to USDA Research Associate Doris Lagos-Kutz, who confirmed it was a garlic mustard aphid (Lipaphis alliariae). Never before seen in North America, the garlic mustard aphid is native to Europe and feeds specifically on the garlic mustard plant (which is also native to Europe but is now a widespread invasive plant throughout the world).

Because the aphid could help control garlic mustard plants, we are interested in figuring out how widespread the aphid is in North America. We started working with volunteer community scientists in 2022 to log observations of the aphid in natural areas. So far, it has been seen all the way from Minnesota to Connecticut, with many sightings in areas in-between. We are continuing this survey to hopefully get a better sense for where the garlic mustard aphid is currently living. If you’re interested in getting involved with the survey, peek at our garlic mustard aphid handout which explains how you can log your observations.