Chionomus haywardi ( Muir, 1929 )

Weglarz, Kathryn M. & Bartlett, Charles R, 2020, A revision of the planthopper genus Chionomus Fennah (Hemiptera: Fulgoroidea: Delphacidae), Zootaxa 4811 (1), pp. 1-63 : 25-27

Chionomus haywardi ( Muir, 1929)

( Figures 11 , 26 )

Delphacodes haywardi Muir, 1929: 83 .

Chionomus haywardi (Muir) , comb. by Fennah, 1971: 324.

Type Locality. Argentina, Santa Fe Province, Villa Ana.

Diagnosis. Body dark brown, with white and stramineous markings. Vertex quadrate; foveae of frons and vertex dark brown, posterior compartments of vertex brown. Carinae distinct, off-white in color; antennae stramineous with fuscous markings. Pronotum white with dark brown shadows directly posterior to eyes; paranota white. Armature of diaphragm forming inverted triangular boss, apex of parameres with inner angle mildly produced dorsally. Aedeagus tubular, 2 converging rows of scattered teeth surrounding apical half.

Description. Color. Macropter. Body dark, brunneous, with white and stramineous markings. Carinae of head (including genal carinae) distinct, off-white in color, usually with a small amount brown at apex of carinae; median carinae of vertex evident. Antennae stramineous, infuscate at joint of the two segments. Pronotum white with dark brown shadows directly posterior to eyes; paranota white. Mesonotum dark to light brown, median and lateral carinae distinctly stramineous. Legs stramineous with brown striping, with hind legs lighter, tarsi brown. Forewings hyaline, distinct dark spot just before apex of clavus. Abdomen brown, some specimens with fine line of white on caudal edge of each segment, lateral projections of sternites yellow to white. Pygofer brown, segment X stramineous. Structure. Body. Length (in mm) macropter ♂ 1.94±0.09 (n=5); width 0.75±0.05 (n=15). Head. Vertex length 0.18±0.03 (n=15); vertex width 0.18±0.01 (n=15); frons length 0.47±0.04 (n=15); frons width 0.21±0.02 (n=15). Macropter. Carinae of vertex distinct, stem of Y-shaped carina evident. In lateral view ( Figure 11b ), fastigium rounded; projecting in front of the eye about 1/4th eye length. Carinae of frons and clypeus distinct ( Figure 11c ), frons nearly parallel, widest at ventral margin of compound eyes. Antennal segments subequal in length, segment II wider than segment I; 2nd segment sparsely setaceous, bearing sensory pits arranged 4, 4, 1, 2, evenly spaced around segment. Sensory pits surrounded by small black setae.

Thorax. Macropter. Carinae of mesonotum evident, median carina ending anterior to scutellum; lateral carinae diverging posteriorly to reach hind margin. Legs with a row of setae on anterior face margin of femora, mostly bare. Calcar bearing 24–25 small teeth. Abdomen. Macropter. Compressed dorsoventrally, tapering caudad to truncate apex.

Genitalia. Pygofer in lateral view nearly half as long dorsally as ventrad, ventral margin sinuate. In caudal view ( Figure 11d , 26a ), as tall as wide, globular; margins rounded, weakly raised at dorsolateral margins. Opening to inner chamber triangular, pointed ventrad. Armature of diaphragm triangular to cordate in shape, smooth or some specimens with toothing along vertical edges, distinctly projecting caudad. Parameres as wide in basal third as at apices, basal angle projecting, rounded; dorsolaterally diverging to flattened apices, lateral margins concave (inner margin more so than outer margin); inner angles acute, dorsally directed; outer angles rounded. Aedeagus circular in cross-section, slightly curved dorsad, widest near base, slightly tapering for most of length, with two rows of scattered teeth surrounding apical; gonopore dorsal, apical. Segment X quadrate, bearing 2 processes; processes well developed, directed ventrad, slightly curved inward at apices. Segment XI produced, about 2/3rds length of segment X.

Plant associations. Oryza sativa L., (rice, Poaceae ); Zea mays L., (corn, Poaceae ); Triticum aestivum L. (common wheat, Poaceae ), Avena sativa L. (common oat, Poaceae ), Hordeum vulgare L. (common barley, Poaceae ) ( Tesón & Remes Lenicov 1989, Velázquez et al. 2003)

Distribution. Argentina, Paraguay.

GenBank accession number. MN339589

Remarks. This species is commonly associated with agriculture, as evidenced by its plant associations. It is similar in outward appearance to C. pacificus but is easily distinguished by range. This species is closely allied with C. havanae and C. balboae (see remarks section on those species).

Type material examined. Holotype [ BMNH]: missing (M. Webb, BMNH pers. comm.).

Paratype. Argentina: Santa Fe, Villa Anna F. C. S. Fe., Jan 1926, K. J. Hayward, Light Trap ( BMNH, 1 female) .

Figures

FIGURE 11. Habitus of Chionomus haywardi. A. dorsal habitus; B. lateral habitus; C. frontal habitus; D. male terminalia, left lateral view; E. male terminalia, caudal view.

FIGURE 26. Line art of Chionomus haywardi, terminalia, A. pygofer, caudal view, B. anal tube, left lateral view, C. aedeagus, left lateral view; D. left paramere, widest view.