Ken, The BugGuide entry for 8203 states that it is "distinguished from the very similar Sycamore Tussock Moth by the lack of a yellowish strip of rectangles running along the costa." However, under 8204, the entry there states "adults in the eastern regions can only be separated from Halysidota tessellaris by genitalia dissection." So . . . take your pick. You can distinguish them . . . or you can't. Seems somewhat typical in the world of moths. Doug Downs Sparta, White County, TN Date: Tue, 16 Aug 2011 13:08:26 -0700 From: kjchilds@xxxxxxxxx Subject: [tn-moths] 8204 Sycamore Tussock To: ncsc-moths@xxxxxxxxxxxxx; tn-moths@xxxxxxxxxxxxx Does anyone know if there is a way to visually separate 8204 Halysidota harrisii from 8203 Halysidota tessellaris? I've been calling what I see here 8203 Halysidota tessellaris but I commonly find Halysidota harrisii caterpillars on my Sycamore trees so obviously there must be adults around. Ken Childs Henderson, TN Chester County http://tinyurl.com/Kens-Moths-2011 http://tinyurl.com/Night-Creatures http://www.finishflagfarms.com