Culiseta kishenehn, Harbach, Ralph E. & Greenwalt, Dale, 2012

Harbach, Ralph E. & Greenwalt, Dale, 2012, Two Eocene species of Culiseta (Diptera: Culicidae) from the Kishenehn Formation in Montana, Zootaxa 3530, pp. 25-34 : 26-31

Culiseta kishenehn , sp. n.

(Figs 1, 2, 4A)

Adults. Darkly ornamented mosquitoes, maxillary palpus, proboscis, legs (except ventral area of femora), wing and abdominal terga dark-scaled; proboscis slender, longer than forefemur; cell R2 longer than vein R2+3, tibiae and tarsi dark-scaled; base of hindcoxa below base of mesomeron; pulvilli absent or inconspicuous.

Female. Head: Ornamentation of head capsule not evident; antenna 1.6–1.7 mm, about 0.7 length of proboscis; maxillary palpus 0.3–0.5 mm, 0.15−0.20 length of proboscis, with 4 palpomeres; proboscis 2.2−2.4 mm, 1.3−1.5 length of forefemur, slightly to moderately bent ventrad (appearing straight in ventral view, specimen no. USNM 547066). Thorax: Black, ornamentation obscured. Legs: Femora without knee spots; forefemur 1.6–1.9 mm, 0.7–0.8 length of proboscis; tibiae slightly swollen distally; ungues simple, fore- and midungues relatively large, equal, hindungues smaller, equal. Wing (Fig. 4A): Length 3.1–3.7 mm (mean 3.3 mm); base of subcosta with sparse(?) setae (radial setae of Maslov, 1989); distal half of wing with outstanding linear scales on most veins; vein R2 longer than vein R2+3 (R2/R2+3 = 1.7–2.0); base of vein M3+4 intersects M1+2 proximal to intersection of mediocubital crossvein with M1+2; anal vein (vein 1A) terminates well beyond intersection of mediocubital crossvein and cubitus. Abdomen: Apically rounded; terga entirely dark-scaled, no evidence of basolateral pale patches. Genitalia: Cerci short, rounded and scarcely visible; 3 spermathecal capsules.

Male. Essentially as female. Head: Antenna about 0.7 length of proboscis; flagellomeres 1–11 each with whorl of very long dense setae, flagellomeres 12 and 13 very long, their combined length greater than total length of preceding flagellomeres; maxillary palpus longer than proboscis (1.1 times as long), comprised of 5 palpomeres, palpomeres 2 and 3 ankylosed, long, about 0.75 length of proboscis, palpomere 3 slightly swollen, bearing setae apically, palpomeres 4 and 5 not noticeably swollen, generally projecting straight forwards or turned slightly upwards, palpomere 4 and base of palpomere 5 with numerous long setae, remainder of palpomere 5 with some relatively short setae; proboscis about 1.4 length of forefemur. Legs: Ungues of fore- and midlegs enlarged, larger anterior unguis with proximal tooth; hindungues small, equal. Abdomen: Terga with well-developed setae along posterior margin. Genitalia: Prominent; gonocoxite elongate, relatively stout basally, gradually narrower toward apex, with crescentiform (ridge-like) basal mesal lobe (basal lobe of authors, gonofurca of Maslov, 1989) apparently bearing row(s) of setae on crest, no distinct apicodorsal lobe (apical lobe of authors); gonostylus borne at apex of gonocoxite, rather long and narrow, undivided; paraprocts of proctiger elongate, heavily sclerotized, with strong apical denticle.

Egg, larva and pupa. Unknown.

Etymology. The Kishenehn Formation is named for Kishenehn Creek. Kishenehn (American spelling) is a Kutenai Native American word meaning “no good”. Why the Kutenai adopted this name for the creek is unknown. The specific name kishenehn is understood to be masculine, but the evidence for usage as either a noun or an adjective is not decisive; consequently, it is regarded here to be a noun in apposition to the generic name of Culiseta , which is feminine.

Systematics. In view of the importance of larval characters for recognizing the subgenera of Culiseta ( Edwards, 1932; Dobrotworsky, 1954, 1960, 1971), it is not possible to place Cs. kishenehn in an extant subgenus. The weakly produced basal mesal lobe of the male genitalia is shared with species of subgenera Culiseta, Climacura Howard, Dyar & Knab and Culicella Felt. The origin of vein M3+4 proximal to the radiomedial crossvein (Fig. 4A,B), the entirely dark-scaled abdominal terga and the absence of an apicodorsal lobe on the gonocoxite of the male preclude the species from being placed in subgenus Culiseta , species which have the base of M3+4 more or less in line with the radiomedial crossvein, banded abdominal terga and an apicodorsal lobe on the gonocoxite. The distal position of the radiomedial crossvein relative to the origin of vein M3+4 and the absence of an apicodorsal lobe on the gonocoxite are characteristics of subgenera Climacura and Culicella . Subgenus Climacura includes five species in different parts of the world: Cs. antipodea Dobrotworsky in southeastern Australia, the type species Cs. melanura (Coquillett) in eastern North America, Cs. tonnoiri (Edwards) and Cs. novaezealandiae Pillai in New Zealand, and Cs. marchettei Garcia, Jeffery & Rudnick in Southeast Asia. Culiseta kishenehn resembles these species, except the last one, in having entirely dark-scaled tarsi and abdominal terga, and also resembles Cs. melanura in having dark-scaled maxillary palpi, which are longer than the proboscis in males. It is not certain, but Cs. kishenehn seems to further resemble species of subgenus Climacura in having few subcostal setae ( Dobrotworsky, 1971). Subgenus Culicella includes 14 species with distributions in Australia (seven species), North America (one species) and the Palaearctic Region (six species). Most of the species have banded tarsi and abdominal terga (three Australian species have unbanded terga and two of these have unbanded tarsi), but in most respects Cs. kishenehn seems to be more similar to species of subgenus Climacura. Considering the North American provenance of Cs. kishenehn and Cs. melanura , their close similarity in adult habitus is unlikely to be due to convergence.

Type series. Holotype male ( USNM no. 546528; Kishenehn no. 505.1), allotype female ( USNM no. 546529, Kishenehn no. 610.4), paratypes males ( USNM nos. 546530‒546533, Kishenehn nos. 624.1, 635.3, 686.1 and 693.1 respectively), Constenius Park (W 113° 42.085¢, N 48° 23.517¢), paratype female ( USNM no. 546534, Kishenehn nos. 20093.1), Disbrow Creek (W 113° 40.999¢, N 48° 22.572¢) and paratype female ( USNM no. 547066, Kishenehn no. 30624.1), Dakin (W 113° 42.173¢, N 48° 23.476¢), Kishenehn Formation, Montana, USA.

FIGURE 1. Culiseta kishenehn , sp. n. A,B. Holotype male ( USNM 546528), (A) head and its appendages, (B) genitalia (tergal aspect). C. Paratype male ( USNM 546530), body, maxillary palpi, proboscis and abdominal terga entirely dark-scaled. D. Paratype female ( USNM 546534), head with short maxillary palpus. E. Allotype female ( USNM 546529), distal part of left wing (dorsal) showing the projecting linear scales and long cell R2. BML = basal dorsomesal lobe; Ppr = paraproct; R2 = cell R2; R2+3 = vein R2+3.

FIGURE 2. Culiseta kishenehn , sp. n. A. Allotype female ( USNM 546529), habitus, appendages of head and thorax entirely dark-scaled (abdomen poorly preserved). B. Paratype female ( USNM 547066), abdomen (left side) and right wing (ventral), terga and wing entirely dark-scaled, long cell R2, apex of abdomen blunt. C. Paratype female ( USNM 546534), apex of abdomen showing the short cercus (partially obstructed by tergum VIII) and three spermathecal capsules. Ce = cercus; R2 = cell R2; SCa = spermathecal capsule; VIII-S = sternum VIII.

FIGURE 4. A. Culiseta kishenehn , sp. n. Left wing of allotype female ( USNM 546529). B–D. Culiseta lemniscata , sp. n. B. Right wing (dorsal) of holotype female (( USNM 547065). C,D. Same as B, (C) base of wing showing subcostal setae (actually on ventral surface), (D) distal portion of wing showing narrow semi-erect fusiform scales on post-costal veins. M2+3 = vein M2+3; rm = radiomedial crossvein; R2 = cell R2; R2+3 = vein R2+3; Sc = subcosta; SuS = subcostal setae.