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

description: Atrichopogon Kieffer
(Figs. 11D–F, 14E, 18E, 23E, 29G, 32D, 34D, 42S–T, 47E, 56B, 72J)
DIAGNOSIS: Only pupa of Ceratopogonidae with terminal process with at least some spicules directed anteriorly.
DESCRIPTION: Habitus as in Figs. 11D–F. Total length = 1.41–3.44 mm. With (Fig. 11F) larval exuviae retained on abdomen. Exuviae with flagellum appressed against lateral margin of face (Fig. 14E). Ecdysial tear anterior or slightly medial to base of antenna (Figs. 14E, 79B); along posterolateral portion of eye. Head: Dorsal apotome (Fig. 18E), without ventral line of weakness, with dorsomedial tubercle, without central dome; dorsolateral cephalic sclerite (as in Fig. 13B) separated from scutum by thin cuticle, separate from scutum upon emergence, each side separated medially by dorsal apotome in whole pupa; mouthparts (Fig. 23E) with mandible, lacinia well-developed, not overlapping apically; palpus extending posterior to posterolateral margin of labium; labium separated medially by labrum, in some by hypopharynx; apex of antenna (Fig. 34D) anterior to posterior extent of midlength portion of midleg (portion lateral to mesosternum); sensilla: dorsal apotomals (Fig. 18E)—1 moderate to elongate seta; dorsolateral cephalic sclerite sensilla—1 short seta or 1 very short or elongate seta, 1 campaniform sensillum; clypeal-labrals (Fig. 23E)—1 seta, 1 campaniform sensillum; oculars (Fig. 23E)—1 campaniform sensillum. Thorax: Prothoracic extension (Fig. 23E) absent; mesonotum with long, bifurcating tubercles, extending posteromedially, completely dividing metathorax medially (Fig. 47E); respiratory organ (Figs. 42 S-T) length/width = 1.25–3.50, variable, knob-like to elongate, with posterior basal swelling or lobe, somewhat flattened laterally, with pores closely abutting or slightly separated at apex of respiratory organ, arranged in single straight or curved row or two widely spaced rows, outer surface smooth or with a few wrinkles, with welldeveloped, flattened pedicel, base without posteromedial apodeme, membranous base of respiratory organ short, tracheal tube straight to slightly curved along length, surface smooth; wing (Fig. 34D) without apical tubercle, separated medially by fore-, midlegs; halter apex and hind leg (Fig. 32D) broadly separate; halter apex abutting anterolateral edge of tergite 2; legs (Fig. 34D) with lateral margin of foreleg near midlength of wing slightly sinuous to evenly curved; hind leg visible at lateral margin of wing (Fig. 32D); with apex of foreleg moderately anterior to apex of midleg; apex of hind leg abutting apex of midleg laterally; sensilla: anteromedials—1 campaniform sensillum; anterolaterals—1 short seta, 1 campaniform sensillum; dorsal setae (Fig. 29G)—D-1-T, D-2-T setae, D-3-T campaniform sensillum; D-2-T, D-3-T on single tubercle in some, or closely associated; supraalar 2—campaniform sensillum present or absent; metathoracics (Fig. 47E)—2 campaniform sensilla; M-3-T near anterior margin of metathorax. Abdomen: without pigmentation pattern, segment 2 as wide or somewhat wider than segment 3, segments with undivided, thin to thick setae, without tubercles or segments 1–5 to 1–8 with branched or setaceous elongate tubercles, tubercles rounded to pointed, tergites or sternites entire, each without membranous disc; segment 9 (Fig. 72J) variable in shape, terminal processes widely separated basally, each projecting posterolaterally, tapering near apex to point, with at least some spicules directed anteriorly; sensilla: tergite 1 (Fig. 47E) with 3 setae, 2 campaniform sensilla, including 2 lateral sensilla, D-3-I absent, D-7-I absent; segment 4 (Fig. 56B)—D-2-IV moderately elongate seta, without tubercle, D-3-IV absent; D-4-IV present; D-5-IV, D-7-IV, D-8-IV, D-9-IV absent; D-4-IV without tubercle, L-1-IV slender or stout, short to elongate seta present or absent, V-5-IV, V-6-IV present or absent, V-7-IV small seta, none on tubercles; segment 8 without D-3-VIII, without L-1-VIII; segment 9 (Fig. 72J)—D-5-IX campaniform sensillum, possibly D-6-IX present but inadequate specimens examined.
DISTRIBUTION AND HABITAT: The genus Atrichopogon is known from 521 species from every Region worldwide (Borkent 2014). Immatures occur in aquatic to terrestrial habitats, generally in shaded areas on algae or mosses present on or at the edge of ponds, marshes and streams, or over wet soil, rock surfaces and wet wood. Larvae and pupae are also found under bark of logs, on rotting leaves, and other moist microhabitats in forests where fungi and microorganisms are available for food.
TAXONOMIC DISCUSSION: The pupae of only 39 species of Atrichopogon have been described (Tables 2–3) and these different significantly in numbers of details. Indeed, the morphology of both larvae and pupae are so diverse that previous workers have suggested that the immatures would provide a better means of distinguishing the species (Nielsen 1951, Ewen & Saunders 1958, Chan & Linley 1988).
Szadziewski et al. (1995) provided a key to European subgenera and Lenz (1934) gave a key to the few European species previously described as pupae. Ewen & Saunders (1958) described 19 species from the New World but did not include a key (in spite of obvious differences between taxa). Nielsen (1951) described six species from Denmark in well-illustrated and detailed study, including their behaviour and biology. His phylogenetic interpretation of the genus included pupal structures. Thomsen (1937) gave a brief key to the three Nearctic species she studied.
The description of A. websteri by Thomsen (1937) suggests it was misidentified. As illustrated, the elongate respiratory organ, the lack of lateral abdominal tubercles and the terminal processes closely approximated medially and with posteriorly directed spicules suggest it is actually a Forcipomyia.
Pupae of Atrichopogon have a reduced number of thoracic sensilla, making the exact naming of these unsure. D-3-T, as a unique campaniform sensillum, is likely homologous to that in other Ceratopogonidae. The abdominal chaetotaxy is also strongly reduced and the remaining sensilla vary in position, making identification of specific sensilla (as in Fig. 56B) often uncertain. Some species have one or two more sensilla on abdominal segment four (e.g. A. maculosus has two lateral setae) and the presence of heavy shagreen in many species makes it particularly difficult to discern sensilla when these are small. In A. jacobsoni, sensillum D-4-IV identified here appears to be homologous to an elongate seta. Furthermore, homologies are further confused by the failure of some descriptions to distinguish tubercles with or without sensilla (e.g. Ewen & Saunders 1958).
MATERIAL EXAMINED: A. bifidus: 1 pupa (of paratype), Nictheroy, Brazil, 31-VII-1923 (CNCI). A. caribbeanus: 2 pupal exuviae (of paratypes) Tobago, Tobago and Trinidad, 31-V-1953 (CNCI). A. corpulentus: 1 pupal exuviae (of paratype), Nanaimo, BC, Canada, 22-VII-1926 (CNCI). A. crinitus: 2 pupal exuviae (of paratypes), Nanaimo, BC, Canada, 22-VII-1926 (CNCI). A. flavus: 2 pupal exuviae (of paratypes), Beaver Creek, Saskatoon, Saskatchewan, Canada, 8-X-1955 (CNCI). A. fusculus: 2 pupal exuviae, Pike Lake, Saskatoon, Saskatchewan, Canada, IX-1956 (CNCI). A. fuscus: 5 pupal exuviae, no locality, coll. by Goetghebuer (so likely western Europe) (CNCI). A. geminus (as A. levis): 3 pupal exuviae, Put-in-Bay, Ohio, USA (CNCI). A. humicolus: 1 pupal exuviae (of paratype), Saskatoon, Saskatchewan, Canada, 9-IX-1955 (CNCI). A. inconspicuus: 4 pupal exuviae (of paratypes), Saskatoon, Saskatchewan, Canada, 17-24-IX-1955 (CNCI). A. incultus: 1 pupal exuviae (of paratype), Siquirres, Costa Rica, 18-VI-1956 (CNCI). A. jacobsoni: 1 pupal exuviae, Batu Caves, Cavern A, Kuala Lumpur, Selanger, Malaysia, 27-XII-1960 (ANIC); 1 pupa, 1 pupal exuviae, as previous locality, 27-XII-1960 (USNM). A. maculosus: 4 pupae, 5 pupal exuviae (of paratypes), Beaver Creek, Saskatoon, Saskatchewan, Canada, 25-28-VIII-1955 (CNCI); 1 pupal exuviae, Patuxent Wildlife Refuge, Prince George’s County, Maryland, USA, 1- VIII-1979 (USNM); 2 pupal exuviae, as previous locality, 10-VIII-1979 (USNM); 1 pupal exuviae, 5 mi NW of Davidsburg, York County, Pennsylvania, USA, 4-VII-1961 (USNM). A. minutus: 4 pupal exuviae, Lit. Abington, Cambs., England, Great Britain, 27-VIII-1924 (CNCI); 2 pupal exuviae, Truro, Canada, 10-VIII-1925 (CNCI); 8 pupal exuviae, Nanaimo, BC, Canada, 22-VII-1926 (CNCI); 11 pupal exuviae, Victoria, BC, Canada, 26-VIII-1947 (CNCI); 14 pupal exuviae, previous locality, 20-VII-1948 (CNCI); 11 pupal exuviae, previous locality, 12-VII- 1948 (CNCI). A. obscurus: 1 pupa, 1 pupal exuviae (of paratype), Mayaguez, Puerto Rico, 25-II-1953 (CNCI). A. remigatus: 1 pupal exuviae (of paratype), Petropolis, Brazil, 27-VII-1923 (CNCI). A. saundersi: 4 pupal exuviae (of paratypes), Mayaguez, Puerto Rico, 27-III-1953 (CNCI). A. tuberculatus: 2 pupal exuviae (of paratypes), Macaras, Trinidad, 14-VII-1957 (CNCI). A. winnertzi (as A. meloesugans): 12 pupal exuviae, Strelly, Notts., England, Great Britain, 3-XI-1922 (CNCI). A. wirthi: 2 pupal exuviae, Chinese Farm, Ft. Pierce, Florida, USA, VII-1987 (CNCI). A. nr. humicolus: no locality given, V-1953 (USNM). A. (Lophomyidium) sp.: 1 pupal exuviae, orilla Rio Dantes, Parque Nacional Barbilla, Cartago, Costa Rica, 10-II-2006 (CNCI). A. sp.: 4 pupal exuviae, 2 pupal exuviae (in glycerin), 6.5 km NW of Enderby, British Columbia, Canada, 27-VI-1990 (CNCI); 1 pupal exuviae, Lake Opinicon, Ontario, Canada, coll. 11-VII-1966, emerged 29-VIII-1966 (CNCI); 1 pupal exuviae, as previous locality, 12-XII-1966 (CNCI); 1 pupal exuviae, as previous locality, 25-VIII-1966 (CNCI); 2 pupal exuviae, St. Pierre de Wakefield, Quebec, Canada, 25-VI-1964 (CNCI); 5 pupal exuviae, orilla Rio Dantes, Parque Nacional Barbilla, Cartago, Costa Rica, 10-II-2006 (CNCI).
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 43-44, DOI: 10.11646/zootaxa.3879.1.1, http://zenodo.org/record/4949051