I do not see any other specimens like this in the other 336 Arabella species illustrated in http://www.boldsystems.org/index.php/TaxBrowser_Taxonpage?taxid=4173, and the 7 specimens there of P. arabella show wide variation in the colouring of the marginal area. P. arabella is just a variable species. I am unclear at the extra reticence to call it that, given that all ID's of moths from photos are fraught. Is the photo sufficient evidence to infer a 338th Philobota species?