Megatibicen, Sanborn, Allen F. & Heath, Maxine S., 2016

Sanborn, Allen F. & Heath, Maxine S., 2016, Megatibicen n. gen., a new North American cicada genus (Hemiptera: Cicadidae: Cicadinae: Cryptotympanini), Zootaxa 4168 (3), pp. 577-582 : 578-580

Genus Megatibicen n. gen.

Type species. Cicada marginata dealbata Davis 1915: 162 (Colorado Springs, El Paso County, Colorado, USA) ( Fig. 1 ).

Species included. The genus is represented currently by the following nine species and one subspecies: M. auletes (Germar, 1834) n. comb., M. cultriformis ( Davis, 1915) n. comb., M. dealbatus ( Davis, 1915) n. comb., M. dorsatus (Say, 1825) n. comb., M. figuratus (Walker, 1858) n. comb., M. pronotalis pronotalis (Davis, 1938) n. comb., M. pronotalis walkeri (Metcalf, 1955) n. comb., M. resh (Haldeman, 1852) n. comb., M. resonans (Walker, 1850) n. comb., M. tremulus (Cole, 2008) n. comb.

Etymology. The name is a combination of mega (Gr. large) and tibicen (L. flute player) in reference to the large size, acoustic abilities and previous classification of the species. The genus is masculine.

Description. Large bodied cicadas (body length 32.5–43.0 mm, expanse of fore wings 90.0–129.0 mm); the abdomen represents about one-half the body length in females but is generally slightly longer in males because of the extended male genitalia; body length is at least two and one-half times the width of the mesonotum. Head: width of head including eyes about as broad or broader than mesonotum ( Fig 1 B); eyes extend slightly beyond the anterior margin of the pronotum; head not as wide as lateral pronotal collar; vertex of epicranium horizontal with distance between supraantennal plate and eye about equal to or greater than length of antennal plate; frons nearly vertical, forming a right or sharply obtuse angle with the dorsum of the postclypeus; distance between ocelli less than distance between lateral ocelli and eyes; postclypeus ranges from more or less truncate, in a continuous line with the supra-antennal plates, to moderately tumid; dorsum of postclypeus about as long or longer than frons; length of rostrum species specific, ranging from middle coxae to beyond posterior coxae. Thorax: pronotum ampliated laterally forming definite lateral fissures ( Fig 1 B), lateral edges smooth, not toothed, occasionally spinose; pronotal collar moderately ampliate laterally, width equal to or slightly less than head width across eyes; length of pronotum shorter then mesonotum; cruciform elevation depression between anterior arms diminishing towards extremities of arms, cruciform elevation much longer than wide; mesonotum obscuring central portion of metanotum; basisternum 3 bulbous; opercula in males large, extending to rim of the tympanal cavity, overlapping medially ( Fig 1 D); meracanthus triangular; female operculum with sinuate posterior margin ( Fig 1 E). Legs: anterior femora with two prominent spines beneath, sometimes with a third smaller spine distally; primary spine erect. Fore wings and hind wings ( Fig 1 A): hyaline; radial and radiomedial crossveins in fore wing oblique, virtually parallel, and frequently infuscated; length of radius posterior between the radial and radiomedial crossveins less than radius posterior between the radial crossvein and the ambient vein; medial and cubital veins arising separately from the arculus; stem of median vein shorter than one half length of discal cell; nodus central; costal margin of the fore wing with at least a few minute spines; radius anterior 1 and subcostal vein not diverging in subapical area; hind wing cubital cell 1 distal end width about equal to or slightly wider than width of cubital cell 2, cubital cell 2 width at distal end greater than anal cell 1, hind wing margin not excessively broad. Abdomen: first abdominal segment in males containing timbal organs; lateral tergites straight or weakly convex; epipleurites reflexed to ventral surface; tergites 2 and 3 about twice as wide as tergites 3–7; second male tergite produced anteriorly on each side into a complete, slightly domed timbal cover, fully rounded dorsally, extending to metathorax, and tightly enclosing timbal cavity, lower margin extending anteriorly from or very near auditory capsule ( Fig 1 C); male sternites IV–VII convex in cross-section, sternite VIII U-shaped in cross-section ( auletes , figuratus and resonans ), much less than the maximum width of sternite VII, or V-shaped in cross-section as wide or about as wide as maximum width of sternite VII. Male genitalia: pygofer of males considerably broadened towards top presenting a triangular shape or with more or less parallel sided in ventral view, distal shoulders broad, rounded, either straight, turned inwards or turned outwards, upper pygofer lobes ill-defined, broadly rounded, internal and lightly sclerotized, basal lobes moderately developed, exposed in lateral view, of moderate length and apically rounded or very long (at least four times longer than wide) and apically pointed, may be against pygofer margin or entirely exposed, dorsal beak well developed, acute and spine-like or absent of poorly developed with broadly rounded basal portion ( Fig 1 F); uncus retractable, short, very broad at base tapering evenly to rounded apex or tapering to an expanded apex with large, rounded, downward turned lateral lobes ( Fig 1 G); claspers absent; aedeagus restrained by tubular encapsulation prior to ventral surface of uncus; theca apex parallel sided or almost parallel sided, sclerotized, with apical serrations on rim, distal half of theca straight or weakly curved upwards with apical portion slightly turned downwards or curved downwards in an arc but kinked near base of curve. Female genitalia: sternite VII of female smoothly bilobed ( Fig 1 I), ovipositor longer than dorsal beak ( Fig 1 H).

Measurements (mm). Length of body: 32.5–43.0; length of fore wing: 40.8–58.3; width of fore wing: 12.2–21.5; length of head: 5.3–7.1; width of head including eyes: 12.1–18.8; width of pronotum including suprahumeral plates: 14.5–19.6; width of mesonotum: 11.8–17.1.

Diagnostic charateristics. The characters described by Hill et al. (2015) as unique to Neotibicen are also diagnostic for Megatibicen n. gen. to separate the new genus from the other Cryptotympanini : timbal covers fully rounded dorsally, extending to metathorax and tightly closing the timbal cavity; male abdominal tergites 2 and 3 much larger than tergites 4-7; bulbous male basisternum 3; aedeagal basal plat bent downward in lateral view, and aedeagus restrained by tubular encapsulation prior to the ventral surface. We can add the following to distinguish Megatibicen n. gen. from Neotibicen : head not as wide as lateral pronotal collar male opercula terminating at rim of tympanal cavity, male sternite VIII Ushaped or V-shaped and as wide as sternite VII in cross-section, pygofer considerably broadened towards top presenting a triangular shape or more or less parallel sided in ventral view, pygofer dorsal beak absent or poorly developed with basal portion broadly rounded or well developed, acute and spine-like, pygofer distal shoulder straight, turned inwards or turned outwards, pygofer basal lobes very long and apically pointed or of moderate length and apically rounded, uncus short, very broad at base tapering evenly to rounded apex or tapering to an expanded apex with large, rounded, downward turned lateral lobes, theca apex parallel sided or almost parallel sided, sclerotized, with apical serrations on rim, distal half of theca straight or weakly curved upwards with apical portion slightly turned downwards or curved downwards in an arc but kinked near base of curve, ovipositor longer than dorsal beak.

Diagnosis. Within the Cryptotympanini , Megatibicen n. gen. can be distinguished from the Neartic genera ( Hadoa Moulds, 2015 , Cacama Distant, 1904 , Cornuplura Davis, 1944 , Diceroprocta Stål, 1870 and Neotibicen Hill & Moulds, 2015 ) of the tribe with a few characters. Species of Hadoa can be distinguished by the head being about as wide as or narrower than the mesonotum and the flat basisternum 3. The head is narrower than the mesonotum and flattened anteriorly, the mesonotum overlaps the metanotum and the five apical cells in the hind wing are unique to species of Cacama . Species of Cornuplura can be distinguished by spines extending from the ventral margin of the pygofer and the hooks on sternite VIII combined with the black basal cell of the fore wing. The radial crossvein in the fore wing is approximately in the middle of apical cell 2, the bifurcated, wishbone-shaped uncus and the acute lateral lobes of the pygofer of males and the sinuate posterior margin to sternite VII of the females can distinguish species of Diceroprocta .

Neotibicen is most similar to the new genus as it is the source of the species for the new genus. Neotibicen can be distinguished from Megatibicen n. gen. by the following characters: head as wide or wider than lateral pronotal collar, male opercula protruding past the rim of tympanal cavity, male sternite VIII U-shaped (V-shaped in davisi and similaris but less than width of sternite VII), pygofer more or less parallel sided in ventral view, pygofer dorsal beak well developed, acute and spine-like, pygofer distal shoulder straight or turned inwards not turned outwards, pygofer basal lobes moderately developed, exposed in lateral view, of moderate length and apically rounded, pointed or bilobed, uncus long and broad with parallel sides throughout its length, arched in cross-section, apex straight in dorsal view or short, wide at base and tapering to a distal finger-like extension subapically with a pair of large ventral spikes, theca apex flared and not sclerotized, distal half of theca evenly curved downwards in an arc possibly kinked near base of curve, ovipositor not as long as dorsal beak (except in N. lyricen Degeer, 1773 ).

Distribution. Species of the genus Megatibicen n. gen. expand across the U.S. east of the Rocky Mountains and Canada. They show the greatest diversity in the central plains with M. figuratus n. comb. and M. resonans n. comb. restricted to the southern and southeastern U.S., and M. auletes n. comb. having the most expansive distribution being found in 31 U.S. states ( Sanborn and Phillips 2013). Megatibicen cultriformis n. comb. has the westernmost distribution being found in AZ, NM and Mexico ( Sanborn and Phillips 2013).

Figures

FIGURE 1. Megatibicen dealbatus n. comb.: A, male and female habitus; B, male dorsum; C, male timbal cover; D, male operculum. E, female operculum; F, male lateral view of genitalia; G, male posterior view of genitalia; H, female lateral view of genitalia; I, female ventral view of genitalia. Scale bar: A, 2 cm; B – E, 5 mm; F – G, 2 mm; H – I, 5 mm.