File:Desmia funeralis – Grape Leaffolder Moth (14750303972).jpg

Mothing Night 7/25/14. Here's what I wrote about this moth: I don't believe the coincidence! I spent at least two hours today going over photos of Desmia funeralis and Desmia maculalis from May and June. I have no idea what prompted this. GUESS WHAT SHOWED UP TONIGHT. A DEFINITE Desmia funeralis. And do you know HOW I know it is funeralis and not maculalis? TOTAL KISMET. As I was studying Desmia funeralis and Desmia maculalis publicly on my FB page, the wise and wonderful Linda Phillips asked me how I knew the difference. Well, I wanted to make sure I was giving her accurate information, so I checked out what the Peterson field guide, MPG and BugGuide had to say on the matter. I discovered on BugGuide that you had to go to a lot more effort to tell them apart than I thought. I didn't know I had to get a dorsal photo to sex the moth, a ventral photo to show the markings on the abdomen and then an accurate measurement of wingspan! In the past, I'd only referred to the wisdom of the Peterson field guide, which made it sound so easy, writing that maculalis "...Resembles Grape Leaffolder [Desmia funeralis] but is smaller. HW often has a stepped white median band. Top of head is dusted with white scales." Well, BugGuide says different and that there's a lot more to it: From Brian Scholtens [on BugGuide]: "The character that I use is the extent of the white patch on the underside of the abdomen. D. funeralis individuals have a solid white patch on the underside of the abdomen on segments 1-5 (or may have a slight break on segment 3). D. maculalis individuals have a broken white patch, where about 1/2 of segments 3 and 4 are clearly dark. Basically, maculalis looks striped on the underside, whereas funeralis looks like it is basically solid white." There is considerable size overlap between male Desmia maculalis and female D. funeralis so it is necessary to sex the moth to be able to identify the species. Fortunately, sexing the 2 species is relatively easy. Males of D. funeralis and D. maculalis have a distinct notch or joint at about the mid-point of each antenna. The hindwing spot on the females of both species is pinched in the middle and on rare occasions may be divided into 2 smaller spots." So, here are the three shots - 1. dorsal (notice the notches on the antennae, so it is a male), 2. ventral (notice there is no broken white patch on the abdomen, so it is funeralis) and 3. WS is approximately 24mm! There! Desmia funeralis!