Oak leaftier rolls the leaf and secures it around itself with silk. Photo by Paul Veirauch.

Localized oak defoliation near Pembine was the work of a combination of caterpillars. Oak leaftier, oak leafroller, and eastern oak looper were all found to be defoliating oak. Oak leaftier and oak leafroller can cause similar symptoms since both caterpillars purposefully roll the leaf around themselves. This trait makes it difficult to spray for them since the chemicals can’t directly reach them. When defoliation is moderate, no control is necessary. 

Oak leaftier and eastern oak looper on a ruler showing their size. Photo by Paul Veirauch.

Additional information on these insects is available at these links:

http://www.forestpests.org/acrobat/oakleaf.pdf

http://www.sicktree.com/idotis/insects/lndloop.html

Written by: Linda Williams, forest health specialist, Woodruff, (Linda.Williams@wisconsin.gov), 715-356-5211 x232.