Melaniphax, Bartlett, 2019

Bartlett, Charles R., 2019, A New Genus and Species of Delphacidae (Hemiptera: Fulgoroidea: Delphacidae) from Costa Rica, Zootaxa 4657 (2), pp. 361-368 : 362-363

Genus Melaniphax gen. nov.

Type species. Melaniphax suffusculus sp. nov., by monotypy and present designation.

Diagnosis. Body dark (shades of brown), carinae concolorous to body, compact, with a slightly hunched appearance, vertex and frons in lateral view appearing smoothly rounded. Wings infused with fuscous. Calcar knife-like, with ~10 distinct teeth. Male pygofer without processes or teeth on ventral margin of opening, armature flattened, dorso-caudally projected in form of medially conjoined pair of semicircles. Gonostyli (~parameres) simple (bearing large tooth on caudal margin below midline, evident in lateral view). Aedeagus broad and short, bearing large lateral flange.Anal tube with pair of large, short and blunt caudally projected processes conspicuous on caudolateral margin and a pair of fine elongate processes originating on anterior ventral margin.

Description. Small, robust, compact; slightly hunchbacked in lateral view. Body dark, carinae concolorous. Head narrower than pronotum ( Fig. 1B ), vertex weakly projected in front of eyes. Vertex approximately quadrate, about equal in length and width. Inflection between vertex and frons smoothly rounded. Frons broad, sides weakly arched ( Fig. 2A ). Medial facial carinae forking above fastigium. Antennae relatively short, segment II somewhat longer than I. Lateral carinae of pronotum laterally arched, not reaching posterior margin. Mesonotum bearing 3 carinae, becoming obscure posteriorly, tegulae conspicuous. Hind leg ( Fig. 1C ) with 2 lateral spines, 1 near femoraltibial joint, 1 near midlength; tibial apex with 5 spinules, arranged 3+2. Basitarsus with 6 apical spinules, arranged 4+2, second tarsomere with row of 4 spinules. Beak reaching (not exceeding) hind coxae.

Forewing ( Figs 1A, 1B ) uniformly infuscated, weakly deflexed at nodal line; venation ( Fig. 3A ) with Sc and RA unbranched, RP 1-2 branched (varies), M unbranched and CuA 3 branched. Metatibial spur ( Fig. 1C ) cultriform, bearing row of distinct black-tipped teeth on posterior margin. 2C

Male genitalia with pygofer triangular in lateral view ( Fig. 2D ); opening in caudal view sinuate, subcircular with keeled margins ( Fig. 2C ), lacking projections or teeth on ventral margin of opening. Gonostyli (≈parameres) ( Figs 2C , 3D ) simple (unbranched), forceps-like, basal angle small (type species bearing tooth on caudal margin just below midline). Suspensorium distinct, elongate. Aedeagus ( Figs 2B , 3B, 3C ) short, flattened and very stout, gonopore ventral, near apex. Male anal tube with stout, truncate caudally directed processes on laterocaudal margin and pair of fine projections from antero-ventral margin.

Remarks. Superficially, Melaniphax gen nov. is similar to Caenodelphax Fennah 1965 (sensu Kennedy & Bartlett 2014). They are similar in both genera having a dark body and deeply infuscated wings, and the male terminalia are grossly similar in a structural sense but differ in numerous details. Melaniphax differs from Caenodelphax in that the former has a hump-backed appearance, with the head in lateral view having a smoothly arced profile ( Caenodelphax has a rounded fastigium, but the face is straight in profile), median carina of frons joined above the fastigium in Melaniphax , below in Caenodelphax . Melaniphax has an inflection of the wings at the nodal line that Caenodelphax lacks. The male terminalia differ in the form of the genital diaphragm (in Melaniphax foliate, dorsocaudally directed, with median V-shaped concavity for reception of the aedeagus, versus in Caenodelphax the diaphragm medially thickened and projected caudally). The aedeagus in Melaniphax is strikingly stout with lateral flanges, whereas Caenodelphax , while somewhat flattened is more nearly tubular. Finally, Melaniphax has a pair of elongate processes originating on the antero-ventral part of the anal tube, lacking in Caenodelphax .

Melaniphax gen. nov. bears some similarities to Akemetopon Weglarz & Bartlett 2011 with regard to the male terminalia. Both genera have simple forceps-like parameres and similar builds to the pygofer, genital diaphragm and anal tubes, but Akemetopon has a ventral tooth on the opening of the pygofer and a tubular, downcurved aedeagus. The similarities may suggest a close phylogenetic relationship among these genera.

Etymology. The “ Melaniphax ” was constructed from the Greek “ melanos ” beaning black, dark; joined with “– phax ”, a truncation of the delphacid genus name ‘ Delphax’. The name is intended as masculine.

Figures

FIGURE 1. Melaniphax suffusculus gen. et sp. nov. (paratype); A. lateral habitus, B. dorsal habitus, C. Apex of hind leg, ventral view.

FIGURE 2. Melaniphax suffusculus gen. et sp. nov. (paratypes); A. habitus, frontal view, B. left lateral view of aedeagus, connective and anal tube detached from pygofer, C. male terminalia, caudal view, D. male terminalia, left lateral view.

FIGURE 3. Melaniphax suffusculus gen. et sp. nov. A. wing venation, B. aedeagus, right lateral view, C. apex of aedeagus, ventral view, D. left gonostylus, widest view.