Leptoconops Skuse
Creators: name: Borkent, Art
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Ceratopogonidae
Leptoconops

description: Leptoconops Skuse
(Figs. 8B–C, 13A, 14B, 18B, 23B, 29B–C, 32B, 34B, 42C–D, 47B, 55B, 72B–E)
DIAGNOSIS: Only pupa of Ceratopogonidae with apically rounded, lobe-like terminal process (Figs. 72B–E); also unique without the hind leg visible laterally along the wing margin and the palpus extending beyond the labium (Fig. 23B); also unique to many species in the presence of thick, recurved setae on abdominal segments (Fig. 55B).
DESCRIPTION: Habitus as in Figs. 8B–C. Total length = 1.69–2.69 mm. Without larval exuviae retained on abdomen. Exuviae with flagellum separate from lateral margin of face (Fig. 14B). Ecdysial tear along anterior to base of antenna, entire head capsule loose (Figs. 14B, 79A). Head: Dorsal apotome (Fig. 18B), with ventral bend uncertain (no alcohol pupal exuviae examined), without dorsomedial tubercle, without central dome; dorsolateral cephalic sclerite (Fig. 13A) separated from scutum by thin cuticle, separate from scutum upon emergence, each side broadly meeting medially in whole pupa; mouthparts (Fig. 23B) with mandible, lacinia well-developed, not overlapping apically; palpus extending posterior to posterolateral margin of labium; labium separated medially by labrum, hypopharynx; apex of antenna (Fig. 34B) anterior to posterior extent of midlength portion of midleg (portion lateral to mesosternum); sensilla: dorsal apotomals (Fig. 18B)—1 short seta, at least 2 campaniform sensillum; dorsolateral cephalic sclerite sensilla—1 short seta, 1 campaniform sensillum; clypeal-labrals (Fig. 23B)—1 very short seta; oculars (Fig. 23B)—1 short seta, 1 campaniform sensillum (barely visible). Thorax: Prothoracic extension (Fig. 23B) absent; mesonotum with moderately sized tubercles, not extending posteromedially, not dividing metathorax medially (Fig. 47B); respiratory organ (Figs. 42C–D) length/width = 1.17–1.95, short, squat or moderately elongate, somewhat flattened dorsoventrally, with pores closely abutting at apex of respiratory organ, arranged in single or double row, outer surface smooth, with elongate conical pedicel, base without posteromedial apodeme, membranous base of respiratory organ short, tracheal tube somewhat curved, expanded apically, with spirals extending just over half length, distally smooth; wing (Fig. 34B) without apical tubercle or angle, separated medially by fore-, midlegs; halter apex and hind leg (Figs. 8B, 32B) broadly separate; halter apex extending to about half length of tergite 1; legs (Fig. 34B) with lateral margin of foreleg near midlength of wing strongly curved, sinuous; hind leg not visible at lateral margin of wing (Fig. 32B); with apex of foreleg ventral to apex of midleg; apex of hind leg abutting apex of midleg laterally; sensilla: anteromedials—6 campaniform sensilla; anterolaterals—1 short seta, 1 campaniform sensillum; dorsal setae (Figs. 29B–C)—D-1-T short or moderately elongate thick seta, D-2-T campaniform sensillum, D-4-T campaniform sensillum or moderately elongate thick seta, D-3-T absent or campaniform sensillum; D1-T, D-4-T closely approximated or on short tubercle, D-3-T posteromedial to D-4-T; supraalar 2—campaniform sensillum; metathoracics (Fig. 47B)—1 seta, 2–3 campaniform sensilla; M-3-T near anterior margin of metathorax. Abdomen: without pigmentation pattern, segments 2, 3 equally or nearly equally wide, segments with undivided, thin and thick, straight or recurved setae, with rounded to pointed, short tubercles, tergites or sternites entire, each without membranous disc; segment 9 (Figs. 72B–E) elongate, fleshy, with short tubercles, terminal processes widely separated basally, each projecting posterolaterally to nearly laterally, tapering to rounded, lobe-like apex; sensilla: tergite 1 (Fig. 47B) with 2 setae, 4 campaniform sensilla, including 2 lateral sensilla, D-2-I a seta or campaniform sensillum, D-3-I absent, D-7-I absent; segment 4 (Fig. 55B)—D-2-IV thick spine on short tubercle, D-3-IV absent; D-5-IV, D-8-IV short, thick, straight or recurved spines; D-5-IV, D-7-IV on separate, short tubercles, D-4-IV, D-8-IV on single tubercle, posterior dorsal sensilla in transverse row, arranged medially to laterally: D-5-IV, D-4-IV, D-8-IV, D-7-IV; L-1-IV short, thick seta on short tubercle, well anterior of posterior lateral setae, L-2-IV, L-3-IV thick setae on short tubercles, V-5-IV, V-7-IV on short tubercles, V-6-IV absent; segment 8 without D-3-VIII, with L-1-VIII; segment 9 (Figs. 72 B-E)—all with D-1-IX seta, D-2-IX, D-3-IX, D-5-IX campaniform sensilla, following in at least some: L- 1-IX, L-2-IX, L-3-IX, V-1-IX, V-2-IX campaniform sensilla.
DISTRIBUTION AND HABITAT: The genus Leptoconops is known from 150 species from every Region worldwide (Borkent 2014) but are restricted to wet or damp sand or sandy soil (generally freshwater or marine beaches protected from wave action), seepage areas in desert oases, wet margins of salt flats, cracked clay soils, halomorphic, calcareous soil, and the margin of vernal ponds in xeric areas.
TAXONOMIC DISCUSSION: Only 14 species of Leptoconops are known as pupae (Tables 2–3). Gutsevich & Glukhova (1970) provided a key to three species known from the former USSR.
Painter (1927) provided first somewhat detailed description of a Leptoconops (L. bequaerti (as Leptoconops sp.)) from Honduras and Ishigami (1959) provided similar details for L. nipponensis in Japan.
Clastrier (1972) in a very detailed morphological study, described and illustrated the pupa of L. gallicus (as L. kerteszi), identifying all parts, describing each sensillum and describing the differences between males and females. His description differs in some details from the generic description here. He shows 1 short seta and 4 campaniform dorsolateral cephalic sclerite sensilla, 1 ocular (campaniform sensillum), 3 anteromedials (campaniform sensilla) and only 1 seta and 1 campaniform sensillum on segment 9. In addition, I record further additional sensilla here. Although some differences may be due to intraspecific variation, it should be noted that the differences are likely due to the difficulty in discerning very small setae or campaniform sensilla, particularly in areas of uneven cuticle. This was the case with Clastrier's (1972) study of L. gallicus, for which I was able to reexamine the species. An SEM study of a species of Leptoconops would be invaluable in better understanding this member of the earliest lineage of Ceratopogonidae, keeping in mind that many of the features of this genus are strongly autapomorphic.
Clastrier & Wirth (1978) provided further details of some Nearctic species, showing that at least some features vary within the genus.
Leptoconops pupae have reduced numbers of sensilla on the thorax and 3–9 sensilla on abdominal segment 9 and naming these was somewhat arbitrary. However, at least L. linleyi had two campaniform sensilla on the terminal process that are likely homologous to the two found on most other Ceratopogonidae.
I examined only one, poorly preserved male pupa specimen of Leptoconops (Styloconops) spinosifrons (with a pharate adult) and this species warrants particular attention, especially as one character state, the lack of recurved abdominal spines (see character 49) may indicate the subgenus is the sister group to other members of the genus. As illustrated by Laurence & Mathias (1972), there may be only one dorsal mesothoracic seta but I could not confidently confirm this. If so, it would be uniquely derived within the Culicomorpha.
Dzhafarov (1962, 1964) described a pupal exuviae as L. bezzii but it clearly is misidentified to genus. In overall habitus it is somewhat similar to Allohelea but details differ from the only known species in that genus. The numerous thoracic setae illustrated, if accurate, suggest it is not even in the Ceratopogonidae. Dzhafarov (1962) does not mention rearing methods nor provides any other indication that the pupal exuviae was definitely associated with either larvae or adults and Dzhafarov (1964) noted the presence of only one pupal exuviae collected from wet soil. The eggs, larvae, and adults described by Dzhafarov (1962) are certainly correctly identified as Leptoconops.
MATERIAL EXAMINED: L. americanus: 1 pupa, 4.4 mi. N. Bodie, Mono County, California, USA, 23-VI- 1965 (USNM); 1 pupa, Saltair, Salt Lake County, Utah, USA, 23-V-1969 (USNM). L. asilomar: 1 pupa, 2 pupal exuviae, ¾ mi. S. Asilomar, Monterey County, California, USA, 21-II-1964 (USNM); 3 pupae, as previous locality, 12-III-1964 (USNM); 1 pupa, as previous locality, 19-III-1964 (USNM). L. bequaerti: 1 pupal exuviae, Great Island, Yarmouth, Cape Cod, Massachusetts, USA, 28-VI-1961 (USNM); 2 pupal exuviae, Ochos Rios, St. Ann, Jamaica, 1969–1970 (USNM); 1 pupal exuviae, Puerto Castilla, Honduras, 1926 (USNM). L. gallicus: 2 pupal exuviae, La Figueirasse, France, 8-VI-1972 (USNM). L. kerteszi: 2 pupal exuviae, La Figueirasse, France, V-1971 (USNM); 6 pupal exuviae, 4 pupal exuviae (in glycerin), Between River Ombrone and Principina a Mare (province of Grosseto), Italy, Spring-Summer, 1999 (CNCI). L. linleyi: 1 pupa, 2 pupal exuviae, Great Island, Yarmouth, Cape Cod, Massachusetts, USA, 28-VI-1961 (USNM); 5 pupal exuviae, Sebastian, Indian River County, Florida, USA, X-1972 (USNM); 3 pupae, as previous locality, 15-X-1994 (CNCI); 4 pupae (in glycerin), as previous locality, 15-X-1994 (CNCI). L. pugnax: 2 pupal exuviae, La Figueirasse, France, 8-VI-1972 (USNM). L. spinosifrons: 1 pupa (with pharate adult), Seychelles Islands, 1970 (USNM). L. whitseli: 9 pupae (of paratypes), 2 pupal exuviae (of paratypes), Pebble Beach, Monterey County, California, USA, 11-VIII-1964 (USNM).
description: Published as part of Borkent, Art, 2014, The Pupae of the Biting Midges of the World (Diptera: Ceratopogonidae), With a Generic Key and Analysis of the Phylogenetic Relationships Between Genera, pp. 1-327 in Zootaxa 3879 (1) on pages 38-39, DOI: 10.11646/zootaxa.3879.1.1, http://zenodo.org/record/4949051