Dietrichana, Zahniser, 2021

Zahniser, James N., 2021, Revision of the New World leafhopper tribe Faltalini (Hemiptera: Cicadellidae: Deltocephalinae) and the evolution of brachyptery, Zootaxa 4954 (1), pp. 1-160 : 49-50

Dietrichana n.gen.

Type species: Dietrichana pampas n. sp.

Diagnosis. Dietrichana can be distinguished from other genera of the tribe by the brachypterous males and female with reticulated forewing venation, ocelli absent, head extremely elongate, crown length 2.5x or more interocular width and median length 5.0x or more length next to eye, crown with median longitudinal carina, and crown texture strongly rugose.

Body. Male, 6.0– 6.5 mm. Female, 8.2–8.8 mm. Body length 5.8x width of pronotum (male), 6.5x (female). Anterior margin of head thin, foliaceous; sharply angled from crown to face. Crown length 2.7x (male)–3.1x (female) interocular width; texture rugose throughout, with pair of round smooth impressed calluses mesad of eyes; with median carina running from base nearly to apex; depressed laterad of median carina. Ocelli absent. Frontoclypeus texture shagreen on posteroventral half, blending into rugose texture on anterodorsal half; depressed medially on anterodorsal half. Antennal sockets situated near anterior corner of eye. Pronotum strap-like; lateral margin carinate; with median cleft, continuing from posterior margin of head; texture rugose around margins and medially, each side with discal region smooth to shagreen. Scutellum rugose to partially shagreen centrally. Protrochanter with stout AV seta and two to three other short stout setae. Profemur short, globose; row AV with 8–9 relatively long thick setae,; intercalary row with 4–5 short thin setae; AM1 present; dorsally with pair of apical setae. Protibia dorsal macrosetae 4+4, relatively short. Mesofemur row AV with numerous stout setae. Mesotibia dorsal macrosetae 5+5, relatively short. Metafemur apical setae 2+1 or 2+1+1 or 2+2+1 (if so, then penultimate pair with posterior seta much thinner than anterior). Metatibia relatively straight in dorsal view. Metatarsomere I short, at most as long as II and III combined; plantar surface with two rows three short, tapered setae; apex with row of 5 platellae flanked on each side by tapered seta. Brachypterous. Forewing with veins reticulated or merging into general rugose texture in parts. Hindwing forming subrectangular strap-like extension from metanotum, truncate apically; anterior margin of hindwing meeting metanotum at ~0.25x distance from posterior margin to anterior margin of metanotum; posterior margin of hindwing not differentiated much beyond posterior margin of metanotum.

Color. General color whitish to yellowish or greenish. Crown with one pair of median ivory stripes contiguous medially for most of length, separated posteriorly, with thin brown border; with or without another lateral pair of ivory stripes, more obscure anteriorly. Face whitish medially, with brown coloration along sutures, antennal pits, below eyes, and laterally on frontoclypeus. Pronotum and scutellum with ivory stripes continuing from head. Forewings raised veins whitish; with pits between reticulations darker; posteriorly with two pairs of dark brown marks. Abdomen with three pairs of ivory stripes, bordered by dark brown; central pair of lines partly contiguous. Pygofer of male and female mostly whitish to yellowish with some brown to dark brown markings.

Male. Pygofer incised dorsally only as short triangular notch at most 1/6 median length; acutely angled posterodorsally, rounded from apex to flat base; without teeth or processes; without long macrosetae, with numerous short setae ventrally and apically. Subgenital plates triangular; median length slightly longer than maximum width; apices bluntly angulate; with numerous short setae scattered across plate, less dense or absent medially near base. Valve broadly triangular; median length about half width; with many short setae posteriorly near apex. Connective Y-shaped, anterior arms well-separated; stem slightly shorter than anterior arms. Style broadly bilobed at base; preapical lobe short, forming short ledge on ventral side; apophysis thick, digitate, mesal margin concave, with two small teeth and some rugose texture on ventral side. Aedeagus with base tall; shaft arising ventrally from base, curving dorsad, without processes; articulated with connective. Phragma forming pair of sclerotized medial plates, somewhat inflated, with patch of distinct setae medially. Segment X membranous; anal tube retracted into pygofer.

Female. Pygofer without long macrosetae, with only very short inconspicuous setae; elongate; apex truncate; ventral margin bisinuate. Ovipositor not extending beyond pygofer apex. Sternite VII relatively large, wider than long; posterior margin broadly excavated. First valvula relatively straight in lateral view; dorsal sculpturing pattern granulose, submarginal with distinct unsculptured band on dorsal margin; VSA present, distinctly delimited, sculpturing granulose. Second valvula slender, without dorsal teeth; with small hump dorsally, about 1/3 from base. Gonoplac with numerous short stout ventrally.

Distribution. Argentina

Remarks. This genus possesses a truly remarkable elongated and flattened head. It is not uncommon for members of grass-specializing groups of Deltocephalinae to exhibit elongation (e.g. Paradorydium Kirkaldy ) or flattening (e.g. Hecalus Stål ) of the head, or both (e.g. Attenuipyga Oman [ Hecalini ]). Its superficial similarity to some Attenuipyga is an extraordinary instance of morphological convergence in these grass-specializing leafhoppers.

Dietrichana was resolved in the Faltala genus group clade, but its closest relative in this group was not clear. More data will help to resolve its relationship to other genera.

Etymology. This genus is named in honor of Dr. Christopher H. Dietrich (INHS) who has provided excellent guidance to students of Cicadellidae and has contributed immensely to the systematics and taxonomy of Membracoidea.

Included species: