Xanthorhoini

Schmidt, Olga, 2015, One century after: a reappraisal of the gnathos (sensu Pierce, 1914) in Larentiinae (Lepidoptera: Geometridae), Zootaxa 3974 (3), pp. 328-340 : 336-338

Tribe Xanthorhoini

Xanthorhoe montanata (see Schmidt 2013, fig. 1). Like in Cataclysme riguata , the distal part of the tegumen is not sclerotized. The lateral somewhat triangular sclerotized projections of the tegumen are fused, not with the base of the uncus, but with the medial portion of the tegumen. However the proximal area of the anal tube with its long weakly sclerotized subscaphium is connected to the triangular sclerotized projections and membrane of the fultura superior (which is ventrad of the anal tube). I propose that the triangular sclerotized projections are homologous with the gnathos although this needs to be tested.

Epirrhoe alternata ( Fig. 17 ). The sclerotization of the distal part of the tegumen is more pronounced than in X. montanata . The gnathos arms are only slightly produced, distally merged with the tegumen and are triangular proximally. The base of the medium sized anal tube with its very thin subscaphium is connected to the gnathos arms and membrane of the fultura superior (which is ventrad of the anal tube).

Catarhoe rubidata ( Fig. 21 ). The gnathos is well pronounced, sclerotized, narrowly articulated with the base of the uncus distally and fused in a complete ring proximally. The base of the very broad anal tube with its medium sized weakly sclerotized subscaphium is fused with the gnathos ring.

Figures

FIGURES 16 – 17. Male genitalia apically: 16. Stamnodes depeculata. 17. Epirrhoe alternata. Gnathos is shown in grey.

FIGURES 20 – 22. Male genitalia apically: 20. Trichopteryx carpinata. 21. Catarhoe rubidata. 22. Idaea humiliata.