Saturday, March 17, 2012

Second Moth of 2012

On Wednesday night, I ran my UV blacklight outdoors for several hours to see if any more moths had emerged. Despite the warm weather (and the lack of a full moon), very few moths came to the sheet. In fact, only one appeared, another micromoth. This one showed very subtle markings under a flashlight beam, but the camera brought out more detail. Having seen many moths like this before, I quickly recognized it as a probably tortricid in the subfamily Olethreutinae. When resting, they tend to look almost rectangular, with the wings rolled so the top and sides look perpendicular to each other.

After looking through the plates at the Moth Photographers Group (currently the best online resource for moth ID in North America), I narrowed the possibilities down to the genus Pseudexentera. The most likely candidates are P. spoliana and P. vaccinii. Both species have been found recently in the same county by fellow birder/mother Todd Dreyer.

Sometimes information about food plants can help narrow down an identification, as some plants are more common in the neighborhood than others. In this case, food plant information is less helpful. P. spoliana, the Bare-patched Oak Leafroller, is known to feed on oaks, of which there are many in my neighborhood. BugGuide does not list a host plant for P. vaccinii, but its name suggests that it uses blueberry plants (Vaccinium sp.), which are also present. (A search of the HOSTS database confirmed my guess.) Above is a Northern Red Oak (Quercus rubra); below is a Highbush Blueberry (Vaccinium corymbosum).