Hemidictyini, Distant, 1905

Sanborn, Allen F., Marshall, David C., Moulds, Maxwell S., Puissant, Stéphane & Simon, Chris, 2020, Redefinition of the cicada tribe Hemidictyini Distant, 1905, status of the tribe Iruanini Boulard, 1993 rev. stat., and the establishment of Hovanini n. tribe and Sapantangini n. tribe (Hemiptera: Cicadidae), Zootaxa 4747 (1), pp. 133-155 : 151-152

Tribe Hemidictyini sensu novo

Type genus Hemidictya Burmeister 1835: 178 .

Diagnosis

Head including eyes narrow, much less than width across lateral pronotal angles; supra-antennal plates extending half the distance to eye; lateral ocelli widely spaced, the distance between the lateral ocelli being greater than between each lateral to the median; postclypeus dorsal length at least as long as dorsal vertex, postclypeus apex rounded in lateral view, rounded in transverse cross section below head. Pronotum with median groove; pronotal collar with paranota weakly developed; mid lateral tooth absent. Mesonotum and metanotum lacking auxiliary sound-producing structures; scutellum distally extended as a long triangular lobe. Opercula small, not covering the tympanal cavity and not completely surrounding meracanthus; meracanthus triangular or nearly so. Foreleg femoral primary spine prostrate. Forewing costal vein equal in width and widely separated from vein R+Sc; CuP and 1A unfused. Hind wing anal lobe narrow with anal vein 3 straight, cubital cell 1 width at distal end not twice or more the width of cubital cell 2; RP and M fused at base. Male abdominal tergites with sides convex in cross section; tergites 2 and 3 each wider than each of tergites 4–7; epipleurites obtusely reflexed to ventral surface. Timbals extended below level of wing bases; timbal covers absent, partially formed ridge on dorsal and ventral posterior timbal cavity. Pygofer dorsal beak absent; distal shoulder undeveloped; upper lobe absent; basal lobe moderately developed. Uncus large, deeply divided, not retractable within pygofer, bent almost at right angle at about 1/3rd its length from base; claspers absent. Aedeagus with theca simple; vesica retractable; conjunctival claws and pseudoparameres absent. Basal plate short, gently upturned apically, not deeply divided basally; rigidly attached to theca, ventral rib ill-defined and fused with surface of basal plate.

Distinguishing features

Differs from all other tribes in having, in combination, the metanotum being covered on the dorsal midline, the multiple reticulations of the forewing, forewing veins CuP and 1A unfused, the pygofer upper lobe absent, and a long non-retractable uncus that is significantly bent posteriorly at about 1/3rd its length from the base.

Hemidictyini can be distinguished from the Chilecicadini by the pronotum lacking parallel sides, the meracanthus not nearly as wide as the operculum, the lack of a broadening on abdominal tergite 2 posterior to the timbal cavity, male abdominal sternite VIII reaching beyond the base of the uncus, the pygofer basal lobe not reaching to the level of the uncus, and the divided uncus bent posteriorly at an approximate right angle. Hemidictyini can be distinguished from the Platypediini by the presence of timbals, the lack of thickened forewing veins for sound production, and the deeply divided, bent uncus. Hemidictyini differs from the Selymbriini in the head that is much narrower than the lateral pronotal collar angles, the straight hind wing anal vein 3, the lack of a complete turnedback rim on the timbal cavity, the lack of a well-developed dorsal beak, and the divided uncus that is bent at an approximate right angle. Hemidictyini differs from the Tettigadini in the head being not as wide as the mesonotum, the lack of dilated pronotal margins, the lack of a mesonotal stridulatory apparatus, and the lack of a coiled aedeagus. Hemidictyini differs from the Tibicinini in the lack of a broadening of abdominal tergite 2 posterior to the timbal cavity, lack of a cylindrical abdomen, the lack of mesonotal accessory sound producing apparatus, and the divided uncus bent at an approximate right angle. Finally, Hemidictyini can be distinguished from Sapantangini n. tribe by the supra-antennal plates extending only half the distance to the eye, the dorsally concealed metanotum, and the deeply divided uncus.

Comments

In the tribal diagnosis we have refrained from including some characters used by Ruschel & Campos (2019) in defining their Hemidictyini , ones that we consider generic characters that show relationships within tribes rather than defining tribes. For example, the number of forewing apical cells, orientation of ulnar cell 3 and development of wing margins, are all characters whose states change readily within tribes, as shown in the cladograms of Moulds (2005) and Ruschel & Campos (2019). We believe that the distinctive forewings and the remarkable elongation of the scutellum in Hemidictya and Hovana are a consequence of generic divergence, similar to that found in the Chlorocystini , that includes both ”leaf-wing” genera and more typical genera, as shown in the phylogenetic analyses of Boer (1995), Moulds (2005), Marshall et al. (2018) and Ruschel & Campos (2019).