Chionomus dolonus, Weglarz & Bartlett, 2020

Weglarz, Kathryn M. & Bartlett, Charles R, 2020, A revision of the planthopper genus Chionomus Fennah (Hemiptera: Fulgoroidea: Delphacidae), Zootaxa 4811 (1), pp. 1-63 : 21-23

Chionomus dolonus , new species

( Figures 9 , 24 )

Type Locality. Argentina, Santiago del Estero, Rio Dulce Road 1km west of Route 9.

Diagnosis. Body brown to dark brown, white and stramineous markings. Vertex quadrate, foveae infuscate. Carinae of frons distinct, noticeably contrasting with foveae, stramineous to cream in color. Antennae yellow. Pronotum dark brown between lateral carinae, light brown shadowing eye, thick white to cream colored band along posterior edge, paranota white. Mesonotum dark brown, shining, lacking white scutellum in males; wings with dark mark at apex of clavus, infuscate along nodal line. Armature of diaphragm shelf-like, produced caudad; apical edge of parameres sinuate. Aedeagus tubular, curved dorsad, subapical posteriorly directed spine on right; segment X with two strong ventrally directed processes, apices blunt.

Description. Color. Macropter. ♂. Body dark, brunneous, white and stramineous markings. Carinae of head (excluding genal carinae) distinct, yellow in color, usually with a small amount brown at apex of carinae; median carinae of vertex evident. Foveae brown, posterior compartments of vertex tan, antennae stramineous. Pronotum white, anteriorly dark brown between lateral carinae, light brown shadowing eyes; paranota white. Mesonotum dark, median and lateral carinae concolorous. Legs yellow, apex of tarsi brown. Forewings hyaline, infuscate along nodal line, dark spot just before apex of clavus. Abdomen brown, caudal edge of each segment yellow, lateral projections of sternites yellow. Pygofer brown. ♀. Similar, mesonotum lighter, centrally light brown reminiscent of vitta, scutellum white. Structure. Body. Length (in mm) macropter 1.83 (n=1); female (♀) macropter 2.06±0.18 (n=3); width ♂ 0.8±0.01 (n=2); ♀ 0.87±0.03 (n=3). Head. Vertex length 0.20±0.03 (n=5); vertex width 0.22±0.02 (n=5); frons length 0.50±0.04 (n=5); frons width 0.24±0.01 (n=5). Macropter. Carinae of vertex distinct, stem of Y-shaped carina evident. In lateral view ( Figure 9b ), fastigium rounded; projecting in front of the eye about 1/4th eye length. Carinae of frons and clypeus distinct ( Figure 9c ), frons parallel ventrad of eyes, narrowing towards fastigium, widest at ventral margin of compound eyes. Antennal segments subequal in length, segment II wider than segment I; 2nd segment setaceous, bearing sensory pits arranged 4, 3, 2, 2, evenly spaced around segment. Sensory pits surrounded by small brown setae.

Macropter. Carinae of mesonotum weak, median carina ending anterior to scutellum, lateral carinae faint, diverging posteriorly to reach hind margin. Legs with sparse rows light brown setae, mostly bare. Calcar bearing 21–25 small teeth (holotype with 24).

Abdomen. Macropter. Compressed dorsoventrally, tapering caudad to truncate apex.

Genitalia. Pygofer in lateral view nearly half as long dorsally as ventrad, ventral margin sinuate, caudally projecting ventral process. In caudal view ( Figure 9e , 24a ), taller than wide, rounded; lateral margins mildly raised. In ventral view ( Figure 9f ), caudal margin sinuate, prominent median projection, quadrate. Opening to inner chamber triangular, pointed ventrad, rounded dorsad. Armature of diaphragm shelf-like, smooth, curved dorsad to fit aedeagus. Parameres, widest in basal third, basal angle produced, rounded; dorsolaterally diverging to anvil-shaped apices, lateral margins concave, inner angles strong, acute; outer angles produced to rounded apices. Aedeagus circular in cross-section, curved dorsad, widest near base, slightly tapering for most of length, gonopore dorsal, apical. Segment X quadrate, 4 processes, 2 arising from apical margin of segment X, strong directed ventrad, hooked, secondary processes small, spine-like, arising from midsection of segment X. Segment XI produced, about 1/3rd length of segment X.

Plant associations. None reported.

Distribution. Argentina.

GenBank accession number. Material for molecular work was unavailable at the time of this study.

Etymology. The specific epithet dolonus stems from the Greek noun, dolon, meaning dagger or stiletto. This name was chosen in reference to the shape of the process of the aedeagus. The noun is neuter and in the genitive plural. The ending – us is an arbitrary combination of letters added to make the epithet euphonious and for gender agreement.

Remarks. Chionomus dolonus is unique to Chionomus in possessing a median ventral process of the pygofer and is thus easily distinguishable. This feature is uncommon among the higher Delphacini , it is notably shared in new world taxa with species of Kosswigianella Wagner, 1963 (sensu Hamilton 2002) formerly in Acanthodelphax Le Quesne, 1964 . Kosswigianella analis ( Crawford, 1914) also shares similar coloration; however, the shape of the aedeagus and parameres of C. dolonus do not fit the description of this genus.

The shape of the parameres and armature of the diaphragm place this species close to C. tenae ; however, the pygofer is much more constricted in this species. It may also be allied with C. balboae , which shares the anvil shape of the apices of the parameres but has a triangular shaped armature of the diaphragm.

Type Material. Holotype [ INHS]: Macropterous ♂, “ ARGENTINA: Stgo. del Estero / Rio Dulce Rd 1 km W rt 9 / S 27°37.589’W 64°37.126’ / 450m, 21 Jan 2008 C.H.Dietrich / vacuum, AR32-1 // ♂ // INHS #2316 [Green paper] // HOLOTYPE / Chionomus / dolonus / KMWeglarz 2012 [Red Paper] ”.

Paratypes: Argentina: Stgo. del Estero , rt 9 SE Termas del T. Hondo , km 1191, 450m, 21 Jan 2008, C.H.Dietrich, vacuum (1 ♂ m, 1 ♀ m); Stgo. del Estero, Staniago del Estero, 300m, 21 Jan 2008, C.H.Dietrich, vacuum (2 ♀ m) .

Figures

FIGURE 9. Habitus of Chionomus dolonus n. sp.(holotype); A. dorsal habitus; B. lateral habitus; C. frontal habitus; D. male terminalia, left lateral view, E. male terminalia, caudal view; F. male terminalia, ventral view.

FIGURE 24. Line art of Chionomus dolonus n. sp., terminalia, A. pygofer, caudal view, B. anal tube, left lateral view, C. aedeagus, left lateral view; D. left paramere, widest view.