Leptoconops (Holoconops) americanus Carter

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 : 20

Leptoconops (Holoconops) americanus Carter

( Fig. 9 , 29 )

Leptoconops kerteszi var. americanus Carter, 1921: 22 (key; female; Utah; fig. head, palpus, claw, antenna, wing stigma; Utah). Rees and Smith 1950 (in part; biology). Rees et al. 1969 (in part; biology).

Holoconops kerteszi var. americana: Johannsen 1943: 776 (combination; misspelled as feminine “ americana ”; fig. female wing, male genitalia).

Leptoconops (Holoconops) americanus: Clastrier and Wirth 1978: 16 (status; key; female, male, pupa; fig. female antenna, palpus, spermathecae, fore tarsomere 1, wing, male genitalia, aedeagus, parameres, gonostylus, palpus, pupal cephalothorax, respiratory horn, abdominal segments; Utah).

Leptoconops (Holoconops) kerteszi , misidentified: Wirth 1952a: 113 (in part; key; female; male genitalia; biology). Fox 1955: 263 (key; taxonomy), Lawyer 1971 (biology; fig. female habitus, egg, larva, pupa; Utah). 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).

Leptoconops kerteszi , misidentified: Rees and Winget 1970 (in part; biology). Rees et al. 1971 (biology; fig. anterior segments of larva).

Tersesthes torrens , misidentified: Pratt 1907: 28 (in part: Salt Lake, Utah, specimens misidentified, according to Carter 1921).

Diagnosis. ( Table 13) Body brown, femora and tibiae darker, tarsomeres brownish yellow; palpal segment 3 sensory pit as deep as wide, broadening internally on female (as in Fig. 11 L . knowltoni); clypeus with four setae, median pair <0.5 as far apart from each other as from corresponding lateral setae; mid tarsomere 1 with at least one submedian spine. Female: stigma posterior margin convex, distal tip rounded; antenna with 11 flagellomeres; flagellomere 11 with two submedian black setae at 0.6–0.7; flagellomere 4 dorsal hyaline sensory seta distal and medial to long black seta, out of axial alignment with corresponding sensory setae on flagellomeres 5–10 (as in Fig. 30 L . sublettei); hyaline sensory setae on flagellomeres 9–10 broadly separated; hind tarsomere 3 ~1.7× longer than 5; spermathecae ovoid, without caplike diverticulum; cerci>3× longer than wide ( Fig. 1 ). Male: tergite 9 with distal shoulders abruptly narrowed to base of adjacent apicolateral processes, with a short dorso-posterior process, ventro-posterior setae separated by ~4× as much as separation of apicolateral processes; gonostylus with three ventral setae spread over 0.2–0.6 of gonostylus length (as in Fig. 22 L . knowltoni), apical lamelliform expansion only partly covering apical tooth (as in Fig. 23 L . foulki); tarsomere 5 basal seta strictly erect, ~0.2 as long as segment (as in Fig. 26 L . foulki).

Distribution. Washington, Idaho, Wyoming, south through Oregon, to California, Nevada, Utah (Box Elder, Grand, Millard, Tooele, Salt Lake, San Juan counties), Colorado.

Larval ecology. Lawyer (1971) collected immatures down to 15 cm in sandy saline soil inhabited by various halophytes, including saltgrass ( Distichlis stricta [Torrey] Rydberg, Poaceae ), red swampfire ( Salicornia rubra A. Nelson , Amaranthaceae ), iodinebush ( Allenrolfea occidentalis [S. Watson] Kuntze, Amaranthaceae ), and foxtail barley ( Hordeum jubatum Linnaeus , Poaceae ) on the shores of the Great Salt Lake, the shores of fresh and brackish water bodies, from sandy marshes and lowlands, and from around the edge of the Kennecott Copper tailings pond.

Life cycle. Rees et al. (1971) colonized L. americanus collected from near the Great Salt Lake and found a life cycle of 30–250 d and several generations a year, eggs and larvae overwinter, eggs survive extended drought and high temperatures, and adult females will feed on rabbit, guinea pig, and human, mate singly or in swarms, live ~8 d, and can reproduce autogenously.

Adult behavior. Clastrier and Wirth (1978) reported adults collected from a calf, deer, sheep, rabbits, and a golden eagle nest. Strickman et al. (1995) reported maximum biting rates were in full sun, with no wind, and when the temperature is>15 °C. One female was collected biting me at ~1600 hours on 12 April 2021 in Hunter Canyon, Grand County (38.504°N 109.5828°W).

Symbionts. Lawyer (1971) observed colonized L. americanus being predated on by a nematode and others fatally internally parasitized by mermithid nematodes.

Remarks. The L. americanus females collected in Grand County lack obvious submedian dark setae on flagellomere 11, have only slightly blunt wing stigma intermediate between figures 2A and 2B of Clastrier and Wirth, and have only the delicate median spines of mid tarsomere 1 as illustrated in figure 4E of Clastrier and Wirth. Brenner et al. (1984a) discuss the difficulty of seeing the flagellomere 11 seta on female L. knowltoni ; hence, this characteristic may also be inconsistent or difficult to discern on L. americanus .

Figures

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

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.