Leptoconops (Holoconops) foulki Clastrier and Wirth

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 : 22-23

Leptoconops (Holoconops) foulki Clastrier and Wirth

( Fig. 21, 23, 24, 26 , 28, 32 )

Leptoconops (Holoconops) foulki Clastrier and Wirth, 1978: 38 (key; female, male; fig. antenna, palpus, spermathecae, male genitalia, gonostylus, palpus; California).

Leptoconops (Holoconops) kerteszi , misidentified: Wirth 1952a: 113 (in part; key; female; male genitalia; biology). Fox 1955: 263 (key; taxonomy). Ryckman 1961 (jackrabbit host). Foulk 1967 (blood meal size). Sjogren and Foulk 1967 (biology). Foulk 1968 (biology). Wirth and Atchley 1973: 45 (in part; key; female, male; fig. female wing, head, genitalia, spermathecae, hind tibial comb, fore tarsomeres 1 and 2, male genitalia; biology).

Diagnosis. ( Table 13) Body blackish brown, femora and tibiae dark brown, fore tibiae slightly pale at tip, mid and hind tarsomeres 1 and all tarsomeres 2 pale brown; clypeus with four setae, median pair ≥0.8 as far apart from each other as from corresponding lateral setae and out-of-line distad of lateral setae by <0.3 their distance apart (as in Fig. 10 L . knowltoni); palpal segment 3 sensory pit as deep as wide, broadening internally on female; mid tarsomere 1 without submedian spine. Female: stigma triangular, pointed; antenna with 11 flagellomeres; flagellomere 11 without submedian black seta; flagellomere 4 hyaline sensory seta laterad of long black seta, in axial alignment with corresponding sensory setae on flagellomeres 5–10; palpal segment 3 sensory pit opening a third the diameter of the interior; hind tarsomere 3 ~1.7× longer than 5; spermathecae with caplike diverticulum; cerci>3× longer than wide ( Fig. 1 ). Male: tergite 9 with distal shoulders abruptly narrowed to base of adjacent apicolateral processes, without dorsal process, ventro-posterior setae separated by ~2× as much as separation of apicolateral processes (as in Fig. 20 L . knowltoni); gonostylus with three ventral setae all within 0.4–0.6 of gonostylus length, apical lamelliform expansion only partly covering apical tooth; apical dilation of paramere with proximal tooth narrow, thumblike; tarsomere 5 basal seta short, erect, curved.

Distribution. Oregon, Montana, south to California, Nevada, Utah (Carbon, Garfield, Juab, Kane, Salt Lake, San Juan, Tooele, Uintah, Washington, Wayne, Weber counties).

Larval ecology. A larval habitat near the Salton Sea in Southern California was characterized by alkali or saline soil dominated by iodinebush ( Allenrolfea occidentalis ) and desert holly ( Atriplex hymenelytra Torrey ex S. Watson , Amaranthaceae ) ( Foulk 1969). Brenner et al. (1984a) clarified that the habitat also produced L. knowltoni .

Life cycle. Sjogren and Foulk (1967) found that, in the laboratory, undisturbed blood-feeding lasted 7–8 minutes; oviposition began ~88 h later; 70– 75 eggs were usually laid, which hatched in 2.5 d at ~32°C; and first generation adults emerged in ~24 d; and, in the wild, a generation was completed in <8 weeks in March–May in Southern California .

Adult behavior and vector potential. Known wild hosts are human ( Clastrier and Wirth 1978) and jackrabbit ( Lepus californicus Gray , Leporidae ) ( Ryckman 1961). Laboratory hosts include rabbits, mice, chicks, and humans ( Sjogren and Foulk 1967). Mullens and Dada (1992a) collected L. foulki from domestic rabbit ( Oryctolagus cuniculus ), Japanese quail ( Coturnix japonica ), and bighorn sheep ( Ovis canadensis nelsoni ), Furthermore, Foulk (1967) found the average replete blood meal to be 0.21 mg (0.20 μl).

Adults have been observed to alight on sunlit sand when its temperature drops to ~41 °C in late afternoon, rest within the top 4 mm of dry sand through the night and return to the surface when the temperature rises to ~18 °C in the morning ( Foulk 1968). I collected a female biting my ear midday on 23 April 2000 in Spanish Valley, Grand County (38.5274°N 109.4997°W), 7 km southeast of Moab.

Brenner et al. (1984a) reported host-seeking activity March–June, and females CO 2 -trapped in the same area in May had high parity rates (up to ~90%), suggesting a high vector potential. It is worth noting, however, that parity profiles are best interpreted along with knowledge of how prevalent autogeny is in the study population. We know little about the details of autogeny in biting midges, but it is quite possible that certain species have obligate autogeny, while others (or even populations within a species) express it at varying levels, based on aspects such as larval nutrition.

Symbionts. Leptoconops foulki ’s propensity to alight on and harbor within the top layer of sandy soil can explain Foulk’s (1968) observation of adults being preyed upon by Myrmeleon immaculatus De Geer antlions ( Neuroptera : Myrmeleontidae ) and parasitized by larval Microtrombidium mites ( Prostigmata : Microtrombidiidae ).

Remarks. Brenner et al. (1984a) discussed the difficulty distinguishing L. knowltoni from L. foulki because the color of the submedian black seta on flagellomere 11 of female L. knowltoni is often difficult to discern.

Figures

Figures 20–26. 20) Leptoconops knowltoni male genitalia, ventral view, aedeagus (A), parameres (P), tergite 9 ventro-posterior setae (s), apicolateral processes (T9alp), gonostylus apical lamelliform expansion (Gsle). 21) L. foulki male genitalia, ventral view. 22) L. knowltoni gonostylus, ventral setae (vs). 23 L. foulki gonostylus. 24) L. foulki parameres (P), proximal tooth (t). Male tarsomere 5, basal seta (bS). 25) L. knowltoni. 26) L. foulki.

Figures 27–32. Female Leptoconops. 27) L. knowltoni flagellomeres 9–11, median black seta (s). Spermathecae (sp), diverticulum (d), neck (spn). 28) L. foulki. 29) L. americanus. 30) L. sublettei flagellomeres 3–6, flagellomere 4 seta bases (sb), hyaline sensory seta (hss). Palpal segment 3. 31) L. sublettei. 32) L. foulki.

Figures 9–15. 9) Leptoconops americanus female clypeus, setae (s). 10) L. knowltoni female clypeus. 11) L. knowltoni female palpal segment 3. 12) L. carteri female palpal segment 3 (Yolo County, CA). 13) L. werneri female tarsomeres 4–5 and claw (paratype, Imperial County, CA [UCRC]). 14) L. werneri male genitalia, ventral view, tergite 9 apicolateral processes (T9alp), meso-posterior lobe setae (s) (Riverside County, CA [UCRC]). 15) L. belkini male genitalia, ventral view, tergite 9 sclerotized lobe (L) (Riverside County, CA [UCRC]).

Figures 1–2. Female lateral habitus (in alcohol). 1) Leptoconops (Holoconops) Kerteszi group. 2) Culicoides (Monoculicoides) sonorensis.