﻿Three new species of the Neotropical genus Smilidarnis Andrade (Hemiptera, Membracidae)

﻿Abstract Smilidarnisduocornussp. nov., S.erwinisp. nov., and S.robustussp. nov. are described, illustrated, and included in a key to the five species here recognized in Smilidarnis. One member of this genus, from Ecuador (new country record for genus), is S.erwini, which differs from its congeners in having distinct coloration and being of intermediate size in terms of overall body length and the relative length of the lateral apical spines. Smilidarnisrobustus (from Peru) and S.duocornus (from Brazil) differ from the other species of Smilidarnis in having the pronotum bearing a pair of suprahumeral spines.


Introduction
There are over 3,500 species of Membracidae worldwide (Bartlett et al. 2018), and very few of those cannot be placed to subfamily based on a combination of leg chaetotaxy, wing venation, and degree of forewing coverage by the pronotum. Of the six genera that McKamey (1998) listed as Membracidae incertae sedis, five have been subsequently referred elsewhere: Antillotolania Ramos and Deiroderes Ramos to Stegaspidinae (Cryan and Deitz 2002), Euwalkeria Goding and Holdgatiella Evans to Nicomiini (Albertson and Dietrich 2005), and Megsaloschema Buckton to Centrotinae (Wallace and Deitz 2004). Only the listed genus Smilidarnis Andrade remained unplaced. Since McKamey's catalog (1998), however, three other unplaced genera have been described, all of which have a pronotum that does not project posteriorly over the scutellum: Togotolania Cryan & Deitz (2002), Smergotomia Dietrich (2008), and Problematode Gaiani (2017). The genus Brachytalis Metcalf & Bruner, which was previously placed in Nessorhinini (Deitz 1975), has since been referred to Membracidae incertae sedis (Wallace and Deitz 2004). Flórez-V. (2019) referred Problematode to Stegaspidinae based on nymph morphology, bringing the total number of unplaced membracid genera back up to four: Togotolania, Smergotomia, Brachytalis, and Smilidarnis. Andrade (1989) described the genus Smilidarnis with two new species, S. fasciatus (from Peru) and S. concolor (from Brazil), leaving it as unplaced Membracidae because it has features of both Smiliinae and Darninae. Like many species of Smiliinae, the forewing veins R and M are basally fused (Fig. 1).
Like Darninae, Smilidarnis has crossvein s (between the branches of the radial veins), two m-cu crossveins in the forewing, and one r-m in the hind wing ( Fig. 1). However, resolving the relationship of Smilidarnis to other treehoppers is further complicated by the results of Dietrich et al. (2017), who found that in some analyses both Darninae and Smiliinae are polyphyletic. In the most recent phylogenetic study of Membracidae , which used seven gene sequences, Smilidarnis was the sister group of Ceresini (Smiliinae). An unlabeled specimen of S. fasciatus is held by The Natural History Museum in London, England (pers. observ.), and a color photograph of the holotype is available online at http://treehoppers.insectmuseum.org/public/figure/show_ zoom/69718 (Deitz and Wallace 2010 [and updates]).

Materials and methods
In quoting labels, quotation marks separate labels and a vertical line separates lines on a label.
A Leica MZ12 stereomicroscope was used to examine structures. The body length was measured using a digital micrometer, as was the relative distances of the eye (inner margin) and ocelli (centers). A manual 5 mm micrometer was used and to determine ratios between other, shorter distances. The abdomen was detached, macerated in a 10% KOH solution at room temperature for 24 h, bathed in water, then acetic acid to stop the reaction. After dissection, structures were stored in a glass microvial containing glycerin and pinned beneath the specimen.
Images were taken with a Canon 5Dsr camera with an adjustable 65mm lens. Photos were taken using Capture One Pro version 10.1.2, 64 bit, build 10.1.2.23 imaging software, aided by CamLift version 2.9.7.1. The specimen was lit using two adjustable Dynalite MH2050 RoadMax flash heads, each attached to a Manfrotto 244 arm. The light was diffused using a lampshade-style cone of translucent paper between the specimen and light sources. After individual focal planes were photographed, they were compiled into a single, composite image using Zerene Stacker -USDA SI-SEL Lab Bk imaging system, version 1.04, build T201706041920. Stacked images were enhanced and edited in Adobe Photoshop CSS Extended version 12.0. The scale bars were generated through Photoshop directly from the metadata of the photo.
The holotype of S. robustus is deposited in the U.S. National Museum of Natural History, Smithsonian Institution, Washington, DC (USNM). The holotype of S. erwini is deposited in the Museo de la Escuela Politécnica Nacional, Quito, Ecuador (EPNC). The holotype of S. duocornus is deposited in the Instituto Nacional de Pesquisas da Amazonia, Coleção Sistemática da Entomologia, Manaus, Brazil (INPA). Distribution. South America.

Smilidarnis
Notes. The only discrepancy between the generic description by Andrade (1989) and the newly described species is that he reported metathoracic tibial cucullate rows II and III double and, by implication, row I single. This pattern is also found in Ceresini (Deitz 1975). In contrast, S. duocornus has row I absent and S. robustus has rows I and III double and row II absent. Among Darninae, some Darnini and some Hemikypthini lack tibial cucullate setae row I, but only some Hemikypthini lack row II (Deitz 1975). Consequently, leg chaetotaxy does not provide evidence resolving the relationship of Smilidarnis to other treehoppers.
The forewing venation of the three new species described here matches that of S. fasciatus, in that the veins R 4+5 and M 1+2 are distally separate; in S. concolor Andrade, those veins are confluent for short distance before the apex. Among all five species of Smilidarnis, only S. concolor has the forewing veins R and M fused then separated preapically (as in Smiliinae). Smilidarnis duocornus and S. robustus resemble each other in the shape of the frontoclypeus and pronotum, as do the other three species resemble each other in these respects.
In some membracids, the presence of abdominal fossae or digitate processes in adults (e.g., see Deitz 1975: fig. 3a) are indicators of scoli in nymphs; the absence of these suggests that the nymphs of Smilidarnis probably lack scoli. Further collecting of these exceedingly rare treehoppers and happenstance rearing is needed to elucidate their biology and immatures. Breadth across suprahumeral spines distinctly greater than breadth across posterior lateral spines (Fig. 2)  Pronotum with central apical spine pale throughout; head vertex with ventrolateral margins and frontoclypeus forming evenly convex curve (Fig. 9) . Diagnosis. Pronotum with pair of suprahumeral spines; pronotum broader across suprahumeral spines than across posterior spines. Description of female. Dimensions (mm). Length of pronotum 7.5; length including wings in repose 9.5; width across suprahumeral spine apices 4.5; width across posterolateral spine apices 3.0; height in anterior view 4.3. Head (Fig. 3). Ocelli circular, below imaginary midline between eyes; distance to eye 1.2× distance between ocelli; vertex with depression ventrolaterally adjacent to ocelli, pair of narrow diagonal depressions dorsally, with distinct sutures and frontoclypeus extending ventrally beyond vertex ventrolateral margins. Pronotum (Figs 2-4) with pair of stout suprahumeral spines; pronotum distinctly broader across suprahumeral spines than across posterior spines; weakly elevated immediately behind suprahumeral spines, this portion roughly trapezoidal in lateral view, abruptly narrowed laterally and expanding again to apical portion that bears pair of widely separated, stout lateral spines directed posteriorly and slender middle spine. Forewing (as in Fig. 1) R and M not confluent for short distance near apex. Leg chaetotaxy. Femora lacking cucullate setae and spines; metathoracic tibia row I lacking cucullate setae, row II cucullate setae sparse in single line, row III cucullate setae dense, single row basally, double row distally. Abdominal terga without pits, fossae, or digitate processes. Color. Head pale brown except darker in depressions and along sutures of frontoclypeus; pronotum pale brown throughout except dark brown mottling in anterior half, at bases of suprahumeral spines, and posteriorly across lateral spines.
Notes. The pronota of S. duocornus and S. robustus, which are both only known from a female holotype, closely resemble each other and have similar coloration. In some treehoppers, such as Quinquespinosa septamacula McKamey (2023), color and surprahumeral spine length is variable, so these differences alone might not suffice for species recognition. Nevertheless, these are considered separate species for several reasons: S. sobustus is almost 3 mm larger; its posterior portion is more elevated, and the apical lateral spines are directed more laterally. Futhermore, the setation of valvifer III is distinct; bearing macrosetae along ventral margin in S. duocornus (Fig. 7), in contrast to that of S. robustus, which bears fine hairlike setae on entire ventral half (Fig. 20).
Etymology. The species is named to honor Terry Erwin for his innovative and revolutionary method of collecting insects through insecticidal fogging of the forest canopy, which has collected many new species, including this one.
Notes. The pronotal apex of S. erwini resembles that of S. fasciatus in having the bases and tips of the posterolateral spines black. In S. fasciatus, however, in addition to other differences, those lateral spines are nearly as long as the middle spine, in comparison to S. erwini, in which they are about half the length of the middle spine, and S. concolor, in which they are even more reduced.
Description of female. Dimensions (mm). Length of pronotum 10.3; length including wings in repose 12.4; width across suprahumeral spine apices 5.0; width across posterolateral spine apices 5.8; height in anterior view 5.1. Head (Fig. 16). Vertex wider than tall, glabrous, without irregular ridges, dorsal margin weakly convex, lateral margins straight; ocelli circular, below imaginary middle line between eyes; distance to eye 1.3× distance between ocelli; midline and frontoclypeal sutures prominent; frontoclypeus extending ventrally beyond vertex ventrolateral margins, with distinct sutures. Pronotum (Figs 14-16). Suprahumeral spines present with robust bases, projecting laterally and slightly ventrally; weakly elevated immediately behind suprahumeral spines, this posterior portion roughly trapezoidal in lateral view, abruptly narrowed laterally and expanding again to apical portion that bears pair of widely separated stout lateral spines and middle slender spine; lateral pair with apices broader than span of suprahumeral spines and directed posterolaterally, middle spine directed posteriorly and not attaining forewing vein M 3+4 . Forewing (Fig. 1) R and M not confluent for short distance near apex. Leg chaetotaxy. Femora lacking cucullate setae and spines; metathoracic tibia row I cucullate setae double, row II absent, row III cucullate setae double.
Etymology. The species epithet is a masculine adjective referring to the overall robustness of this species' pronotum.