The Purdue Plant and Pest Diagnostic Laboratory

What's Hot at the P&PDL
May 13, 2013

Maple Petiole Borer

Tim Gibb, Insect Diagnostician, Department of Entomology, Purdue University

Feeding damage by maple petiole borers may be the cause of fallen maple leaves beneath your trees. Examination of the petiole on fallen leaves should reveal a hollow hole. The tiny larvae tunnel in the petioles, or leaf stems, causing them to break from the blade of the leaf. The adult is a small, four-winged wasp known as a sawfly. Maple petiole borer infestations are infrequent and unpredictable and do not appear to harm tree health so insecticidal control is not recommended.


Click on image to enlarge

Fallen leaves under a maple tree

Petiole damage

maple leaves

Above images courtesy of Mick and Connie Hardy, Summitville, IN

Maple petiole borer larva
Photo by Steve Mayer

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service