Neotrocnada Krishnankutty & Dietrich 2012, New Genus
Creators: name: Krishnankutty, Sindhu M.
name: Dietrich, Christopher H.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cicadellidae
Neotrocnada

description: Neotrocnada, New Genus
Type species: Neotrocnada napoensis sp. nov.
Diagnosis. This genus is readily distinguished from other Iassini by the broad, nearly vertical vertex, the narrow frontoclypeus, the horizontal ventral part of the head, the absence of an appendix on the forewing, and the foliaceous front tibiae.
Description. Medium-sized, robust, stramineous leafhoppers with diffuse fuscous markings dorsally. Head short and very broad, crown not developed, crown nearly vertical, without conspicuous transverse striations. Ocelli small, well separated from eyes and frontoclypeus, equidistant from eyes and midline and from dorsal margin and antennal ledge. Antennal ledge, large and flaplike, margin transverse, concealing two basal antennal segments in anterior view; antenna short, length less than half width of vertex. Frontoclypeus (Fig. 25) with abrupt transverse fold at level of antennal ledge, ventral part horizontal, weakly convex with median concavity, maximum width 1.25X distance between lateral margin and eye; lateral frontal suture not extended dorsad of antennal ledge. Transclypeal suture well developed. Gena broad, weakly angulate laterally, largely concealing proepisternum. lorum weakly convex, maximum width approximately equal to that of anteclypeus, narrowly separated from genal margin ventrally, lateral suture incomplete dorsally. Anteclypeus weakly convex, slightly tapered from base to apex, apex even with genal margin. Rostrum moderately broad, tapered, extended to middle trochanter.
Pronotum (Figs 23, 24) wider than head, strongly declivous anteriorly, with conspicuous transverse rugae extended laterally onto pro- and mesepimeron; lateral margin carinate, moderately long, evenly divergent posterad. Exposed part of mesonotum with reticulate texture medially, rugose laterally; scutellum transversely rugose; mesonotum and scutellum together shorter than broad, shorter than pronotum, not extended beyond midlength of clavus. Forewing steeply tectiform at rest; opaque sclerotization covering most of clavus and present but less dense in basal two thirds of corium; small punctations with minute recumbent setae densely distributed in clavus and more sparsely distributed in basal 2/3 of corium; venation well delimited, complete, crossvein s present basad of rm2, 2 r-m and 3 m-cu crossveins (3 closed anteapical cells) present; vein R with 5 branches; inner apical cell very small and narrow, same texture as that of adjacent cells; appendix absent. Hind wing veins R4+5 and M1+2 confluent distally. Front femur with dorsoapical pair of stout, pale setae; AM1 undifferentiated; intercalary group scattered; AV and PV each with few long setae near base; tibia foliaceous (Fig. 26), dorsal surface flat and AD and PD margins expanded; setal rows poorly differentiated, ventral surface with dense band of short setae extended from near base to apex. Middle femur with dorsoapical pair of stout, pale setae and few fine ventral setae; tibia resembling that of front leg but longer and narrower and with dense group of short pale setae near apex. Hind femur setal formula 2+1 with penultimate seta very close to apex; tibia rows PD, AD, and PV with approximately 25, 12, and 14 macrosetae, respectively; setal bases of row AD enlarged but not spinelike; tarsomere I without enlarged dorsoapical seta, row AV with dense band of short setae, PV with single row of cucullate setae, pecten with 5 platellae; tarsomere II with single cucullate seta and 3 platellae.
Male abdomen. 3S apodemes weakly developed. Genital capsule in repose strongly retracted into pregenital segment. Sternite VIII ca. 1.8x longer than sternite VII, completely concealing ventral part of genital capsule, including subgenital plates and most of posterior pygofer margin, in repose. Pygofer (Figs 27, 28) with tergite well developed, posterior margin transverse, fused to pygofer lobes; lobe densely clothed with short, fine setae dorsoapically, with less dense ventral group of short fine setae; ventral processes (pygofer hooks) highly modified (Fig. 29), resembling subgenital plates, freely articulated slender, somewhat depressed, with band of sparse fine setae ventrally, apex curved dorsad and tapered to acute tip. Anal tube membranous, with few short stout ventral setae. Valve (Fig. 28) rectangular, more than twice as long as wide, broadly fused to pygofer; subgenital plates (Fig. 29) reduced to pair of small median posterior digitiform lobes, fused to valve and extended between bases of pygofer hooks. Connective (Fig. 32) well sclerotized, V-shaped, articulated to aedeagus. Style (Fig. 31) small, slender, apodeme weakly developed, apophysis digitiform. Aedeagus (Figs 33, 34) simple, tubular, U-shaped in lateral view, with pair of ventrolateral arms at base, apex bifid, without processes, gonopore apical. Conjunctiva between aedeagus and anal tube membranous, without distinct sclerites.
Female. Unknown.
Etymology. The genus name, a feminine noun, was formed by appending the prefix neo - (new) to the name of an Australian iassine genus, Trocnada Walker, that has superficially similar head structure.
Notes. Neotrocnada will run to couplet 5 in Blocker’s (1979) key to New World Iassinae (sensu stricto). The two genera included in that couplet, Goblinaja Kramer and Baldriga Blocker, resemble Neotrocnada in having the pronotum strongly declivous anteriorly, the crown poorly developed, the forewing without an appendix, the front tibia flattened and expanded, and the number of hind femoral macrosetae reduced. Neotrocnada is readily distinguished from these two genera in having the antennal ledges enlarged and horizontal, and the frontoclypeus with a transverse fold separating the vertical dorsal section from the horizontal ventral section. Neotrocnada also has the forewing venation much more clearly delimited than in the other two genera.
The male genital capsules of Goblinaja, Baldriga, Gargaropsis, and Neotrocnada are modified to such an extent that the homologies of some structures are difficult to interpret. In particular, the ventral part of the capsule in the first three genera has a prominent median posterior lobe that extends below a pair of articulated hooklike structures. The genital capsule of Neotrocnada is similar to those of the three mentioned genera but differs in some important respects. Instead of a single median ventral lobe, the posteroventral margin of the genital capsule of Neotrocnada has a pair of small, closely appressed digitiform lobes. These lobes are fused to each other at the base but are separated from the valve by a distinct suture, suggesting that they represent the vestigial subgenital plates. Because this structure is in the same position as the single median lobe found in the other three genera, the latter presumably also represents the fused and reduced subgenital plates. As a further source of confusion, Neotrocnada has a pair of structures articulated to the ventral part of the genital capsule that strongly resemble the subgenital plates of other leafhoppers. However, if the small digitiform lobes are vestigial subgenital plates, then the subgenital plate-like structures of Neotrocnada must be homologous to the pygofer hooks of the other three mentioned genera. The pygofer hooks of Neotrocnada are more elongate, somewhat depressed, and curved upward rather than hooked ventrad apically. An alternative interpretation, i.e., that these structures are indeed homologous to the subgenital plates of other leafhoppers and that the median ventral lobe(s) of the genital capsule in these four genera are novel structures, seems implausible because some other New World iassines (e.g., Momoria) have articulated ventral pygofer hooks similar to those of Gargaropsis but also retain well developed subgenital plates.
description: Published as part of Krishnankutty, Sindhu M. & Dietrich, Christopher H., 2012, Two new iassine leafhopper genera from Ecuador (Hemiptera: Cicadellidae), pp. 43-50 in Zootaxa 3530 on pages 47-49, DOI: 10.5281/zenodo.282780