TIPS Project:

Garlic mustard aphid

2023 Complete

Final report

During 2023 there were 28 new reports of garlic mustard aphid confirmed via EDDMapS in Minnesota; 27 with exact coordinates. Most were around the Twin Cities, one was in Rochester, two west of Winona and one north of Wilmer. This broadens the known distribution of garlic mustard aphids in Minnesota westwards. There is one confirmed report of garlic mustard aphid near west of Sioux City, Nebraska. There were no absence reports.

Image from EDDMapS

Garlic mustard (Alliaria petiolata) is an established invasive understory plant in most Minnesota counties and is on the Noxious Weed Restricted list. Many volunteers and natural resource managers hand pull or foliar treat garlic mustard. A non-native host specific insect, garlic mustard aphid (Lipaphis alliariae), has been discovered in the upper Midwest, including Rochester, the Twin Cities and Duluth. This terrestrial invasive participatory science (TIPS) project will help volunteers and resource managers report both the presence and absence of garlic mustard aphid.

Photo by A. Gupta, spring ephemerials on the south Zumbro trail, Rochester, MN.

Why it matters

Many native understory plants are negatively impacted by invasive garlic mustard and many, many volunteer and professional hours are spent hand pulling or spraying it. This project will help us better understand the density and distribution of garlic mustard aphid and its biocontrol potential. It is possible that garlic mustard aphid may one day help us protect our lovely understory plants.

Photo by Rebecah Troutman, Holden Forests and Gardens, Bugwood.org

Garlic mustard aphids

Garlic mustard aphid (Lipaphis alliariae) is a non-native insect that lives on garlic mustard. It is known to feed on the stems, seeds and leaves of garlic mustard causing the plant to be misshapen and possibly disrupt seed development. This project hopes to better understand their impact on garlic mustard.

Report any aphid found on garlic mustard, we're only expecting to find garlic mustard aphid; if something else is found that could also be very informative.

Resources

How to use EDDMapS

This new 4:54 video demonstrates how to use EDDMapS. Note for this project "positive" means you are reporting the presence of garlic mustard aphid so provide images of the aphid. "Negative" means you did not find garlic mustard aphid, so the image should be of garlic mustard only. One absence (negative) report from each garlic mustard stand you work in or visit would be great. We would like unique presence (positive) garlic mustard aphid reports for each garlic mustard or garlic mustard clump/stand with aphids (use the polygon feature) you see. We expect there to be far fewer garlic mustard aphid reports then garlic mustard absence (negative) reports.

Great MIPN resource

In 2021 Holden Forest & Gardens and the Midwest Invasive Plant Network (MIPN) did a similar project and produced this great 2 page handout. It can be found online as a PDF. If you'd like to check it out click here to download.

Examples of good garlic mustard identification pictures

garlic mustard aphid on flower

garlic mustard aphid on seed capsule

garlic mustard on seed capsule

close up of garlic mustard aphid

Four photos above by Rebecah Troutman, Holden Forests and Gardens

All questions about this project should be directed to Angela Gupta, UMN Extension Forester, agupta@umn.edu

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