Abstract
For 30 years the highly distinctive Schneider’s Surprise butterfly, Tiradelphe schneideri Ackery & Vane-Wright, 1984, has been known only from the two original type specimens, both female. Here we describe and illustrate the previously unknown male of this Guadalcanal endemic member of the Danaina—the subtribe of Nymphalidae: Danainae to which Tiradelphe has always been assigned. Unexpectedly, male T. schneideri completely lack alar androconia, and are thus unlike all other species of Danaina and its sister group, the Amaurina. The new information will permit a reassessment of the phylogenetic relationships of Tiradelphe. This enigmatic genus may well be more isolated than previously supposed, with implications not only for our understanding of pheromone communication in these insects, but also the evolution and biogeography of the tribe Danaini in the Indo-Pacific.