Transtilliana Brown 2024, new genus

Transtilliana Brown, new genus LSIDurn:lsid:zoobank.org:act: 94CB458B-92A2-41F2-85B1-CB44E188D222 Type species: Transtilliana biloba Brown, new species. Diagnosis. Superficially, Transtilliana is similar to Vargasia, but the male genitalia are quite different, in particular, the shapes of the uncus, transtilla, and phallus (Figs. 22, 23). It is also somewhat reminiscent of Strophotina Brown owing to its size, forewing shape and coloration, and long labial palpi (Figs 3, 4). However, whereas the forewing of Strophotina has a pronounced and well defined semicircular costal patch, only a hint of such a feature is present in Transtilliana. The genitalia of the two genera show no similarities. The combination of the narrow, parallel-sided valvae with a conspicuous excavation at the distal margin, and the bilobed transtilla serve to distinguish Transtilliana from all other genera. In the female genitalia, the apophyses anteriores are rather short (shorter than the apophyses posteriores), and the bilobed sterigma shows some similarities to those of Ptychocroca Brown and Razowski and Foikeulia Urra, with which adults are not similar. Description. Head: Vertex rough-scaled, with scales directed anteriorly over frons, scales of frons shorter, more appressed to surface; antenna ca. 0.5 length of forewing, non-serrate, with one row of scales per flagellomere, sensory setae 1.0‒1.1 times width of flagellomere in male, shorter and sparser in female; ocellus well developed, slightly larger in female; chaetosemata well developed; labial palpus with scaling greatly expanded distally on second segment, nearly concealing third segment, combined length of all segments 2.8‒3.0 times diameter of compound eye in male, ca. 3.5 times diameter in female. Thorax: Dorsum smooth-scaled, metathoracic tuft absent.Legs unmodified,without hairpencil or other secondary scales. Forewing length ca. 2.4 times width; costa evenly arched throughout, without costal fold in male; termen straight, oblique; all veins present and separate, chorda and M-stem absent, R 4 to costa, R 5 to termen. Hindwing with all veins present and separate; CuP weak at margin; frenulum with one bristle in male, three in female. Abdomen: Male genitalia (Fig. 22) with tegumen and vinculum rather elongate; uncus short, ovate from rounded-triangular expansion of dorsum of tegumen; socius short-digitate, pendant, densely covered with fine setae; gnathos arms simple, sclerotized, joined distally into V-shaped, pointed process; transtilla with a pair of small rounded, submedian lobes directed ventro-posteriorly, lacking spines; valva broadest in basal 0.33, comparatively narrow, somewhat parallel-sided in distal 0.66, outer margin with conspicuous concavity, sacculus weakly sclerotized, with small triangular process from venter ca. 0.66 from base; juxta a broadly V-shaped plate; phallus long and slender, ca. 0.9 length of valva, cornuti absent. Female genitalia (Fig. 41) with papilla analis slipper-shaped, somewhat angled postero-laterally, ca. 3 times as long as wide; apophyses slender, posteriores ca. 1.25 length of anteriores; sterigma bilobed anteriorly, each lobe subtended posteriorly by a narrow arched sclerite; ductus bursae long, slender, uniform in width throughout, ca. 0.8 times length of corpus bursae, with antrum well-defined, sclerotized, cup-shaped; corpus bursae membranous, somewhat pear-shaped, lacking signum. Etymology. The generic name refers to the unusual transtilla in the male genitalia.