Leptoconops (Holoconops) knowltoni 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 : 23-24

Leptoconops (Holoconops) knowltoni Clastrier and Wirth

( Fig. 10, 11 , 20, 22, 25 , 27 )

Leptoconops (Holoconops) knowltoni Clastrier and Wirth, 1978: 26 (key; female, male; fig. female palpus, spermathecae, antenna, male genitalia, gonostylus, palpus; California). Ronderos and Spinelli 1992: 45 (key; female, male diagnoses; Brazil). Borkent and Spinelli 2000: 9 (in Neotropical catalog).

Leptoconops (Holoconops) kerteszi , misidentified: Wirth 1952a: 113 (in part; key; female; male genitalia; biology). Fox 1955: 263 (key; taxonomy). Foulk 1966 (biology). Foulk 1969 (biology). Jones et al. 1972 (Texas, horse). 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 bequaerti (Kieffer) , misidentified: Wirth and Atchley 1973: 39 (misidentified record from Padre Island, Texas [ Ronderos and Spinelli 1992]).

Diagnosis. ( Table 13) Body brown, femora and tibiae pale brown, fore tibia yellowish apically, tarsomeres 1, 2 yellowish; 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; 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 with submedian black seta at ~0.7; flagellomere 4 hyaline sensory seta laterad of long black seta, in axial alignment with corresponding sensory setae on flagellomeres 5–10; hyaline sensory setae on flagellomeres 9–10 usually fused into a single hypertrophied seta; palpal segment 3 sensory pit opening a third the diameter of the interior; hind tarsomere 3 ~1.7× longer than 5; spermathecae somewhat pyriform, with caplike diverticulum (as in Fig. 28 L . foulki); 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; gonostylus with three ventral setae spread over 0.2–0.6 of gonostylus length, apical lamelliform expansion broadly covering subapical tooth; tarsomere 5 basal seta curved, as long as ~0.4 length of segment, decumbent.

Distribution. Idaho, Montana, south through California, Nevada, Utah (Box Elder, Grand, Millard, San Juan, Tooele, Utah, Washington counties), Arizona, Texas, Sinaloa, to Santa Catarina ( Brazil).

Larval ecology. A habitat adjacent to a small creek near the Salton Sea in Southern California characterized by scattered iodinebush ( Allenrolfea occidentalis ) and desert holly ( Atriplex hymenelytra ) and sandy alkali or saline soil with 10–13% moisture produced abundant L. knowltoni larvae along with larval Culicoides mohave Wirth and Dasyhelea festiva Wirth ( Foulk 1966) . A similar habitat near the Salton Sea also produced L. foulki ( Brenner et al. 1984a) . Of the 19 males collected in the present study, 13 were collected at 38.54606°N 109.59159°E, and four were collected 0.3 km south at 38.54458°N 109.59424°E, suggesting the traps were placed near the larval habitat. The other two specimens were collected 9 and 42 km from those sites.

Adult behavior and vector potential. Leptoconops knowltoni has diurnal early to midmorning and late afternoon biting activity peaks with a midday lull ( Foulk 1969; Brenner et al. 1984a). Foulk (1969) also noted that attack rates markedly declined when the human host stopped moving. Furthermore, Brenner et al. (1984a) reported host-seeking activity near the Salton Sea June–October and CO 2 -trapped female parity rates up to 58% in the same area, suggesting high vector potential (however, see L. foulki adult behavior and vector potential section). Known hosts are human, brush rabbit ( Brachylagus idahoensis [Merriam], Leporidae ) ( Foulk 1969), horse ( Foulk 1969; Jones et al. 1972), and sheep ( Clastrier and Wirth 1978).

Symbionts. Foulk (1969) reported that>143 of 26,951 female L. knowltoni were parasitized by Microtrombidium mite larvae. That no males were parasitized suggests that the mites use female midges to disperse to other habitats when the females oviposit.

Remarks. See L. foulki remarks.

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