Atopocelyphus ruficollis (Macquart)

Gaimari, Stephen D., 2017, The dipteran family Celyphidae in the New World, with discussion of and key to world genera (Insecta, Diptera), ZooKeys 711, pp. 113-130 : 115-121

Atopocelyphus ruficollis (Macquart)

Celyphus ruficollis Macquart, 1844: 253; Planche 34, figs 4, 4a.

Specimens examined.

Type. French Guiana. 1 syntype male (Figs 4-5, 9-12, 17-18); MNHN: Specimen MNHN-ED-ED8696 (permalink http://coldb.mnhn.fr/catalognumber/mnhn/ed/ed8696), in the Macquart collection. Labels (Fig. 2; explanation below, in Remarks) as follows: 2896 / 34 [handwritten, circular label, pale green on opposite side]; 535 [handwritten]; Celyphus / ruficollis [handwritten]; TYPE [red label]; HOLOTYPE [red label]; MNHN, Paris / ED8696. Pinned through mesonotum; good condition (antennal flagellomeres both broken off, right fore tarsus broken off, lower third of the right wing missing, lower edge of left wing damaged).

Additional specimen. French Guiana: Réserve Trésor, xii.2009, Window trap, N 4°36'37.6" / W 52°16'44.5", altitude = ± 225 m. 1 female (Figs 6-8, 13-16, 19-20); BMNH, mounted on triangular point, scutellum removed and mounted on top of point; excellent condition.

Description.

Body (Figs 4-8) length (head through base of halter, plus base of halter through abdomen tip, to account for differential curling of the abdomen), [4.6-] 5.6 mm. Head through thorax length, including scutellum (head through posterior edge of scutum, plus scutellum), [6.2-] 6.4 mm. Head and thorax predominantly orange.

Head (Figs 9-11, 13-15). Head length (excluding antennae) [0.9-] 1.1 mm, height [1.1-] 1.2 mm, width [1.6-] 1.8 mm; 1.6 [-1.8] × wider than long, 1.5 X wider than high. Vertex rounded; inner vertical seta incurved, 0.25 mm; outer vertical seta outcurved, 0.2 mm; postocellar setae cruciate, 0.2 mm, thinner than vertical setae; distance between inner and outer vertical setae subequal to distance between outer vertical seta and postocellar seta. Ocellar triangle equilateral, with distance from one ocellus to another 0.1 mm. Frons length (anterior ocellus to lunule) [0.55-] 0.65 mm, width [0.8-] 0.9 mm parallel sided, extending [0.16-] 0.18 mm anteriorly beyond edge of eye. Median vitta visible as roughened texture relative to fronto-orbital area being smooth and shiny (in holotype, only visible from dorsolateral aspect); width at ocellar triangle 0.2 mm, expanding anteriorly to 0.25 mm at lunule. Antennae (Figs 13-14) separated by [2.5-] 3 × width of an antennal base, rounded between antennae with no facial keel; scape and pedicel orange; scape length [0.15-] 0.25 mm, widening distally, fully exposed; pedicel 0.18 [-0.2] mm, with enlarged dorsal seta and 2 slightly enlarged ventral setae. Antennal first flagellomere black except orange basally to aristal base (broken off in holotype); length 1.05 mm; height 0.1 mm, slightly expanded distally to 0.15 mm at tip. Arista orange, becoming slightly darker distally; length 0.9 mm, not extended beyond tip of first flagellomere; plumose, with rays up to 0.15 mm. Face flat in upper 2/3, descending sharply from plane of frons; lower 1/3 of face + subgena recurved anteriorly. Gena narrow, with white pruinescence at interface with parafacial; 2 small, fine genal setulae (not evident in holotype). Subgena larger than gena, and bulging; with dark brown spot confluent with dark brown spot at lower corner of face. Clypeus narrow, dark brown ventrally. Palpus black, yellow basally, slightly flattened and spatulate, fuzzy and with several longer thin setulae.

Thorax (Figs 4-6, 15). Scutum dorsal length 1.5 mm, width at suture 2.0 mm; lateral length (anterior edge to halter) [2.0-] 2.2 mm. Scutellum (Figs 5, 7-8) length [3.8-] 4.2 mm, width [2.8-] 3.4 mm, height [1.3-] 1.5 mm, extending beyond apex of abdomen (Fig. 4); concave ventrally, with sharpened ventral edge; dorsal surface smooth with irregular dimpling; ventrally hairy anterolaterally, with tiny hairs scattered throughout venter. Postpronotum with 1 small postpronotal seta, otherwise bare dorsally, setulose ventrolaterally; patch of small black setulae medial to postpronotum on anterior surface of mesonotum. Proepisternal seta present, short and fine. Prosternum orange, lightly fuzzy, but lacking setae or setulae. Mesonotum with dorsocentral setae 1 + 3, small and hair-like; with smaller and hair-like acrostichal setulae (1-2 presutural, 3 or 4 postsutural), with prescutellar pair slightly thickened (obscured by pin in holotype); 1 strong supra-alar seta above wing base; 2 fine postalar setae present; notopleuron with 2 black setae, posterior one stronger than anterior. Anepisternum and katepisternum orangish brown and with sparse whitish setulae; posterior margin of anepisternum with short black anepisternal seta (slightly longer than inner vertical seta); upper margin of katepisternum with 2 subequal, short, fine black katepisternal setae (broken off in holotype).

Wing (Figs 12, 16). Wing length [4.2-] 4.5 mm, height [2.0-] 2.1 mm; sapromyziform, with spinules on costa ending at tip of R2+3; hyaline, but darkened brown basally and within costal cell, subcostal cell, and along costal vein to point between apices of R1 and R2+3, along vein R2+3 except apical 1/4, and with some slight darkening on R4+5 and crossvein r-m; veins brown except yellow on distal half of costal vein and distal parts of veins R2+3, R4+5 and M1; costal vein ends at apex of M1; crossvein r-m slightly beyond midpoint of discal cell; CuA1 short, 1/5 length of crossvein dm-cu, not reaching wing margin; A1+CuA2 short; A2 present only as darkened fold. Halter brown.

Legs. Legs orangish brown, except as noted. Fore coxa orange; femur yellow orange, becoming dark brown distally, with 1 strong preapical posteroventral seta and row of [4-] 5 long thin posterodorsal setae; fore tibia dark brown, with 1 apicoventral spur and 1 strong preapical dorsal seta; fore tarsus with tarsomere 1 white, slightly longer than tarsomeres 2-5 combined, ventrally with dense pad of thickened orange yellow setulae; tarsomeres 2-5 dark brown. Mid coxa dark brown; mid femur setulose, but with no outstanding setae or setal rows; mid tibia with basal and apical parts dark brown, with 1 apicoventral spur and one strong preapical dorsal seta; mid tarsus with tarsomeres 1-2 yellow, tarsomeres 3-5 brown, ventrally with dark brown setulae. Hind coxa dark brown; hind femur setulose, but with no outstanding setae or setal rows; hind tibia with basal and apical parts dark brown, lacking apicoventral spur and preapical dorsal seta, but inner edge of apex with tight comb of yellowish brown setulae; hind tarsus with tarsomeres 1-2 pale yellow, tarsomeres 3-5 light brown, tarsomere 1 ventrally with dense pad of thickened orange yellow setulae, ventral setulae of remaining tarsomeres dark brown.

Abdomen (Figs 17-20). Abdomen length [2.2 -] 2.5 mm, width [1.8 -] 1.9 mm. Syntergite 1+2 and tergites 3 and 4 flattened (top part of tergites 3 and 4 of holotype missing due to dermestid damage), brown pruinose dorsally (Fig. 19) and shiny dark brown to blackish blue laterally; tergites 5 and 6 shiny dark brown to blackish blue (depending on angle of view); tergite 7 light brown. Tergites recurved laterally underneath abdomen, such that lateral parts visible from below; sparsely setulose, mostly smooth; tergite 4 with slight medial notch along posterior edge; tergites 5 and 6 each subdivided or creased medially, with strong triangular notch along posterior edge (Figs 18, 20); tergite 7 saddle-shaped. Sternites brown, irregularly hairy and with sparse setulae; each sternite wider than long.

Male terminalia (Fig. 17). Epandrium saddle-shaped, about as long as wide, concolorous and fitting easily within saddle-shaped tergite 7; surstylus small, bilobed distally, hairy on lobes (no other characteristics visible without dissection).

Female terminalia. Hypoproct orange, longer than wide, rounded distally, covered with pale brown setulae. Epiproct brownish, short, rounded distally, covered with dark setulae. Cerci orange, slightly longer than wide, with mixed pale and dark brown setulae, a few elongate.

Remarks.

Crosskey (1971) discusses in detail the labeling standards in the Macquart collection, which are directly applicable to this specimen (Fig. 2). The circular label is green on one side, meaning it is from the Americas, and the handwritten number on the white side is the accession number, which represents the MNHN serial number given to the collection to which the specimen formed a part, and the year of accession, in this case 2896 / 34 (serial number 2896, year of accession 1834). This accession number is found in the accessions book at the MNHN (Fig. 3), titled "Catalogue des Animaux articulés Crustacèa, Arachnidea, Insectea, reçus, donnés échangés ou achetés comprenant les années 1826 à 1834. Tome I." Within this catalogue is the line for accession number 2896 in the “Série 1834", as follows (columns separated by “/”): Insectes donnés / par Mr F.R.M. Leprieur d’un voyage fait en / Amérique / 550 [specimens]. As discussed by Crosskey (1971), Macquart’s type labels did not consistently indicate “n.sp.” (or similar) at the time of this publication, although he did start to consistently use this term on his labels after this time.

Besides these generalities of labeling of Macquart types, Pont (2012) also dealt with specimens of Leprieur from French Guiana in the MNHN, which, along with discussion with Adrian Pont, significantly aided my current interpretations of the labels on the type. The accession number 2896 refers to Leprieur’s collections in French Guiana. Noting that the label is slightly ripped at the bottom of the first number of the year, it is likely that this was accessioned in 1834, which is consistent with the types of the muscids Limnophora elegans Macquart and Spilogaster maculipennis Macquart, both collected by Leprieur "de la Guyane" from the same publication (Macquart, 1844). There is also reference in Pont (2012), but not Crosskey (1971), to an old handwritten 3 digit number label for the two preceding species, and the type of Celyphus ruficollis similarly has such a number label, 535. The handwriting on these labels is clearly that of Macquart, in comparison with labels presented by Crosskey (1971) and Pont (2012), and other Macquart specimens in the MNHN seen by the author. It is possible that this number represents a sort of "unique identifier" of the time, given that the Catalogue indicates 550 specimens were donated (i.e., that this was specimen 535 of 550). Another alternative is that the number was a reference to the species itself (i.e., that this number was a reference to Macquart’s notes on this species, although no such notes have been located). In any case, the meaning of this secondary number remains a mystery.

It is worth noting that Macquart’s description at least partly contradicts his figure 4a (plate 34) (Fig. 1), in that the description states that the arista is inserted near the tip (i.e., subapical, as is typical of all other celyphids), while the figure shows the arista as clearly subbasal. Unfortunately, the type specimen has lost the first flagellomere and arista, and given that the condition of these structures is important to the definition of this new genus, a further comment is warranted. In the newly collected specimen, the antennae are quite elongate, well beyond that of any other Celyphidae , and the arista is plumose and placed subbasally, all unique states in this species relative to other celyphids. Macquart (1844) does not mention an elongate antenna, and his figure 4a (plate 34) (Fig. 1) does not show an antenna of such length, but it does show the subbasal placement and the plumose condition of the arista, so it remains a possibility that the first flagellomere itself was broken (i.e., appearing short) when Macquart examined the specimen, and only later completely broke off and was lost. Also note, neither the type specimen nor the new specimen possess what appears to be the fronto-orbital setae pictured in figure 4a (plate 34) (Fig. 1). This is significant because Frey (1941) specifically refers to this figure to point out that this species is likely not a celyphid due to the presence of these setae.