Chionomus pacificus Weglarz & Bartlett 2020, new combination
Creators: name: Weglarz, Kathryn M.
name: Bartlett, Charles R
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Delphacidae
Chionomus
Chionomus pacificus

description: Chionomus pacificus (Crawford, 1914), new combination   
(Figures 13, 18g & j, 28)  
 Megamelus pacificus Crawford, 1914: 626.   
 Liburnia pacifica (Crawford), comb. by Van Duzee, 1917:84.   
 Delphacodes pacifica (Crawford), comb. by Muir & Giffard, 1924: 34.   
 Type Locality. California.   
 Diagnosis. Body brown to light brown, with distinct median vitta and ivory to cream markings. Vertex quadrate, foveae infuscate. Foveae of frons dark; carinae distinct, noticeably contrasting with foveae, stramineous to cream in color. Antennae light cream colored to yellow. Pronotum light, white to cream in color, infuscate shadows directly behind eyes, paranota white. Mesonotum brown with median white vitta; wings with dark mark at apex of clavus. Armature of diaphragm bifurcate, hooked along entirety; parameres sinuate, outer angles enlarged. Aedeagus tubular, with two rows of teeth along sides on distal 2/3rds.   
 Description. Color. Macropter. Body brown to dark brown, matte, with cream or white markings. Carinae of head (including genal carinae) distinct, ochraceous to off-white in color; median carinae of vertex evident. Foveae of frons dark brown; vertex lighter than frons, foveae infuscate. Antennae cream to light brown, segment I dark brown in some specimens. Pronotum white to cream, fuscate markings directly posterior to eyes and between median and lateral carinae. Mesonotum dark brown to brown, median and lateral carinae cream to white, space between carinae also lightened. Legs white to light brown; apex of tarsi brown. Forewings hyaline, faint fuscous spot just before apex of clavus. Abdomen brown, fine line of white on caudal edge of each segment, lateral projections of sternites white. Pygofer brown. Brachypter. Similar to above, tegmina infuscate, white stripe along apex, darkened spot near apex of clavus. Structure. Body. Length (in mm) macropter ♂ 1.93±0.14 (n=31); ♀ macropter 2.21±0.12 (n=6); ♂ brachypter 1.85±0.05 (n=9); width ♂ 0.78±0.06 (n=50); ♀ 0.88±0.06 (n=6). Head. Vertex length 0.17±0.03 (n=50); vertex width 0.19±0.03 (n=50); frons length 0.50±0.03 (n=25); frons width 0.22±0.02 (n=25). Macropter. Carinae of vertex distinct, stem of Y-shaped carina evident. In lateral view (Figure 13b), fastigium rounded; projecting in front of the eye about 1/4th eye length. Carinae of frons and clypeus distinct (Figure 13c), frons subparallel, narrow at vertex, widest at ventral edge of compound eyes. Antennal segments subequal in length, segment II wider; 2nd segment bearing sensory pits arranged 4, 4, 2, 1, evenly spaced around segment. Brachypter. Same as above.   
 Thorax. Macropter. Carinae of mesonotum evident, median carina ending at scutellum, lateral carinae distinct, parallel, reaching hind margin. Legs sparsely setaceous. Calcar bearing 22–25 small teeth. Brachypter. Same as above except lateral carinae of mesonotum diverging; tegmina apically rounded, reaching past pygofer.   
 Abdomen. Macropter. Compressed dorsoventrally, tapering caudad to truncate apex. Brachypter. Same as above.   
 Genitalia. Pygofer in lateral view (Figure 13d) nearly half as long dorsally as ventrad, ventral margin sinuate. Pygofer in caudal view (Figure 13e, 28a), about as tall as wide, rounded; margins rounded, slightly produced dorsolaterally. Opening to inner chamber triangular, pointed ventrad. Armature of diaphragm bifurcate, hooked along entirety, distinctly projecting caudad prior to dissection, apices of hooks pointed ventrad when fully dissected. Parameres, widest in basal half, basal angle mild, rounded; dorsolaterally diverging to expanded apices, lateral margins concave, inner angles weak, pointed; outer angles produced, rounded. Aedeagus circular in cross-section, slightly curved ventrad, directed dorsoposteriorly, widest near base, slightly tapering for most of length. Aedeagus with two rows of scattered teeth reaching from gonopore to ventral margin in apical 2/3rds; gonopore dorsally directed, apical. Segment X quadrate; bearing two weakly produced processes, projected posteriorly, hooked. Segment XI produced, about 1/2 length of segment X.   
 Plant associations. Medicago sativa L., (alfalfa, Fabaceae); Solanum tuberosum L. (Irish potato, Solanaceae), Beta vulgaris L. (common beet, reported as ‘sugar beet’, Chenopodiaceae); Larrea tridentata (DC.) Coville (creosote bush, Zygophyllaceae); Lepidium thurberi Wooton (Thurber’s pepperweed, Brassicaceae) (all label information).   
 Distribution. USA:AZ, AR, CA, CO, FL, GA, KS, LA, MS, NM, NV, NC, OK, SC, TX, WI; Mexico (Chiapas, Chihuahua, Durango, Hidalgo, Jalisco, Mexico, Mexico City, Morelos, Nuevo Leon, Querétaro, San Luis Potosí, Sonora, Tamaulipa), Costa Rica, Guatemala, Panama, Colombia, Venezuela; also reported IL, UT; Mexico (Michoacán, Oaxaca) (Wilson and McPherson 1980b, Bartlett et al. 2014).   
 GenBank accession number. MN339590   
 Remarks. There is a large amount of variation in color for C. pacificus, some specimens are dark with the vitta faint and marking stramineous while others are light with almost perfectly white markings and distinct vittas. This species is closely allied with C. bellicosus and C. puellus (see the remarks for C. bellicosus).   
 Type material examined. Holotype [USNM]: Macropterous ♂, under Megamelus pacificus, “Cala / 2351 [Handwritten]// Collection / CF Baker // Type / No. 15996 [Number handwritten] / U.S. N.M. [Red paper] // Megamelus / pacificus / D.G.C. Crawf [Handwritten, label with black border]”.
description: Published as part of Weglarz, Kathryn M. & Bartlett, Charles R, 2020, A revision of the planthopper genus Chionomus Fennah (Hemiptera: Fulgoroidea: Delphacidae), pp. 1-63 in Zootaxa 4811 (1) on pages 29-31, DOI: 10.11646/zootaxa.4811.1.1, http://zenodo.org/record/3944031