Culicoides (Selfia) denningi Foote and Pratt

Phillips, Robert A., 2022, Culicoides Latreille and Leptoconops Skuse biting midges of the southwestern United States with emphasis on the Canyonlands of southeastern Utah (Diptera: Ceratopogonidae), Insecta Mundi 2022 (907), pp. 1-214 : 80-81

Culicoides (Selfia) denningi Foote and Pratt

( Fig. 36 , 281)

Culicoides denningi Foote and Pratt, 1954: 20 (key; female, male; fig. female wing, mesonotum, palpus, male genitalia; Saskatchewan).

Culicoides (Selfia) denningi: Fox 1955: 235 (assignment to subgenus Selfia ; key and diagnoses of subgenera; species key; taxonomy). Atchley 1970: 229 (key; female, male, pupa, larva; 24 fig.). Atchley 1971b: 55 (pupa; geographic variation; comparison with C. jamesi and C. hieroglyphicus ). Atchley 1973: 630 (female, pupa; comparison with C. jamesi and C. hieroglyphicus ). Wirth et al. 1985: 32 (numerical characters; fig. female wing). Murphree and Mullen 1991: 362 (key; larva; numerical characters; fig. head, mandible, hypostoma, epipharynx).

Culicoides hieroglyphicus Malloch , misidentified: James 1943: 148 (in part; male genitalia variant; seasonal distribution, Colorado).

Diagnosis. ( Tables 14, 15) Brown; wing without pattern of pale spots; three unsclerotized or faintly sclerotized long fingerlike spermathecae; male scutellum with six setae; hind tarsomeres with apical spines; posterior margin of male sternite 9 with pair of prominent caudomedial lobes slightly longer than wide; gonocoxal apodeme simple, expanded apically, without hooklike process; gonocoxite not abruptly expanded basally; apex of gonostylus rounded clublike, without tooth; aedeagus Y-shaped; parameres fused, about as long as wide, median process slightly longer than wide, rounded.

Distribution. Washington, Saskatchewan, Alberta, south through Idaho (Custer County, new state record), Montana, Wyoming, South Dakota, to Oregon, Nevada, Utah (Cache, Duchesne, Garfield, Grand, Juab, Millard, Uintah counties), Colorado, Kansas ( Swanson et al. 2018), Nebraska.

Larval ecology. Atchley (1970) collected pupae from a clear 25 °C stream at 1590 m in Elko County, Nevada, from small to large and fresh to polluted 17–33 °C stream and river margins at 1370–2160 m elevation in Garfield, Juab, Millard, and Uintah counties, Utah, and, along with larger numbers of immature C. jamesi , from a small highly polluted creek at 730 m elevation in Montana. During a multi-year study, Fredeen (1969) found that C. denningi larvae migrate from the margin to the mid-channel of the South Saskatchewan River ( Canada) before it freezes, overwinter in the vegetation-free riverbed sand, and swim to shore to pupate in the spring.

Adult behavior. Culicoides denningi can be a severe crepuscular pest of horses and humans to at least 1.2 km from its larval habitat but would also bite throughout calm cloudy days ( Fredeen 1969). Jones (1965) reported sheep as a host for C. hieroglyphicus ; however, Atchley (1970) states that the report may be mistaken and instead be for C. denningi . Two female C. denningi were collected in Grand County while biting humans: one 11 August 1999 in Castle Valley (38.64°N 109.41°W) and one on my ear midday 3 May 2000 in east Moab. Two females were collected by T. Graham while biting a human 12 November 2017 in Canyonlands National Park, San Juan County (38.15339°N 109.82893°W).

Symbionts. Female and male C. denningi were parasitized by larval mites ( Table 10).

Remarks. James’s (1943) description of a C. hieroglyphicus male genitalia variant collected in Larimer County, Colorado, is that of C. denningi . The distributions of C. denningi and C. hieroglyphicus overlap in northern Colorado, Utah, and Wyoming; and they are more closely related to each other than to other Selfia species ( Atchley 1970).

Figures

Figures 33–36. 33) Culicoides moabensis female (top) and unidentified brown C. subgenus Selfia female (bottom), lateral habitus (in alcohol). Male genitalia, ventral view focused on aedeagus. 34) C. brookmani, basal arm of paramere (Pa), distal tip of median process of paramere delineated (Pt), basal arm of aedeagus (Aa), tip of median process of aedeagus (At), gonocoxite (Gc), gonostylus (Gs). 35) C. moabensis, median process of paramere (Pmp) (paratype). 36) C. denningi, sternite 9 caudal lobes (S9cl).