Ocyptamus maximus Thompson, 2018

Mengual, Ximo, Miranda, Gil Felipe G. & Thompson, F. Christian, 2018, Unraveling Ocyptamus and the Baccha legacy (Diptera: Syrphidae): redefinition of groups and new species descriptions, Zootaxa 4461 (1), pp. 1-44 : 15-16

Ocyptamus maximus Thompson sp. nov.

Figs 11 , 28 , 32–37 , 113.

Ocyptamus CR-45 Thompson in litt.

Ocyptamus maximus Thompson in litt. Arcaya et al. (2013).

Differential diagnosis. Although described as Ocyptamus , this species is incertae sedis regarding its generic affinities (see Comments below). Very large fly, almost completely dark with tawny wings and hyaline costal area. Abdomen petiolate, dark, tergum 2 with two anterolateral yellow/translucent maculae and two medial, divergent orange fasciate markings.

Description. MALE: Head ( Figs 28 , 32, 34 ). Face brownish black except for very indistinct orange vitta running from antennal base to level of tubercle, sparsely grayish microtrichose, slightly denser laterally, black pilose; gena orange, shiny and bare on anterior 2/3, brown, dull and black pilose posteriorly; mouthparts orange; occiput black, densely grayish-white microtrichose, white pilose on ventral half, black pilose dorsally, with pile in 3–4 rows at medial notch, and a single row on dorsal 1/5; frontal triangle black, shiny and bare on anterior 1/2, brownish-black microtrichose and black pilose posteriorly; vertical triangle equilateral, black, black microtrichose and pilose; antenna brown, black pilose; ratio 1:1:2, with basoflagellomere about twice as long as broad; arista bare, about 1/3 shorter than antenna. Thorax ( Figs 32, 33 ). Dark brown except postpronotum and scutellum lighter brown (almost tan); scutum brown microtrichose with lighter brown medial and submedial microtrichose vittae, black pilose, without any distinct anterior pile; scutellum light brown microtrichose, black pilose, without ventral pile fringe; pleuron dull, densely gray microtrichose on katepisternum and posterior anepisternum, black pilose; plumula short, light brown; calypter brownish black, with margin and fringe black, pile long on both calypters; halter and capitulum pale; metasternum bare; metathoracic episternum black pilose. Legs: brownish black except femoral-tibial joints lighter orange brown, black pilose. Wing: microtrichose, light brown except darker on basal cells, cell r1 and r2+3; alula normal, broad, about as broad as cell cup. Abdomen ( Figs 32, 33, 35 ). Petiolate, with 2nd segment about half as wide medially as apically; tergum 1 brownish black, dull, black pilose; tergum 2 brownish black except for translucent yellow divergent yellow vitta on basal 2/3 and with similar but smaller brownish orange divergent vitta posterior to the yellow and narrowly separated by black color, black pilose; terga 3–5 black, black pilose; sterna 1 and 3–5 black, black pilose; sternum 2 translucent yellow on basal 2/3, black apically, black pilose; 8th segment with a small protuberance. Genitalia: small, cercus orange, as in fig. 113.

FEMALE ( Figs 36, 37 ). Similar to male except normal sexual dimorphism, frons black, shiny on anterior 1/3, black microtrichose with lighter gray microtrichose medial vitta, black pilose; tergum 6 short, about 1/3 as long as tergum 5, black, black pilose; ovipositor orange.

Length (n=1). Body, 22.4 mm; wing, 16.8 mm.

Geographical distribution. Colombia, Costa Rica and Venezuela.

Type-locality. COSTA RICA: Puntarenas Prov., Parque Nacional La Amistad, Zona Protectora Las Tablas, Las Alturas de Cotón , Estación Biológica Las Alturas , 1569 m., 8°56'43'' N 82°50'00'' W.

Material examined. Holotype, male, deposited in the Instituto Nacional de Biodiversidad ( INBio), Santo Domingo de Heredia, Costa Rica, and labelled: “ COSTA RICA. Prov . Puntarenas. Z. P. // Las Tablas, Estacion Biológica Cotón. // 1569m. 22 JUL 1999. M. Alrao. // Manual L _S_320400_593800 #57455” “ INB003309582 // INBIOCRI COSTA RICA ” [barcode] “ Holotype // Ocyptamus maximus // Thompson 2013 ” [light red, handwritten] ( Figs 32, 33 ) . Paratypes: COLOMBIA: Sierra Nevada , San Lorenzo, J. Ujhelyi (1♀ FSCA) . COSTA RICA: Puntarenas Prov., Finca Cafrosa, Embalse, 800 m north de Tigra , L_S_317800_ 596200, 1280 m, 15.viii.1997, A. Picado, #47694 (1♀ USNM, INBIOCRI002559410 INBIO) ; Puntarenas Prov., Sabalito, Camino a la Neblina , L_S_317800_ 597500, 1340 m., 22.viii.2000, M. Alfaro, #58936 (1♂ USNM, INB0003306083 INBIOCRI) ( Figs 11 , 28 , 34, 35 ) . VENEZUELA: Lara, P.N. Terepaima, 1200 m., 6.viii.1976, J.M. Osorio (1♀ MJMO, CE-UCLA /DS-1235) ( Figs 36, 37 ).

Etymology. The specific epithet is derived from the Latin maximus , which means ‘greatest’ ( Brown 1956: 516), as this is the largest known species of Ocyptamus and of the subfamily Syrphinae . Species epithet is an adjective.

Comments. Ocyptamus maximus is readily recognizable as this is the largest known species of the subfamily Syrphinae . Only some species of the Eristaline genus Milesia are larger.

O. maximus seems to be more morphologically closely related to sargoides Macquart than to any other taxon listed here based on a similar pattern of translucent maculae on the tergum 2 and sternum 2, the long black pile on the dorsal lobe of the calypter, and male genitalia (similar overall shape of phallus, postgonite and surstylus). Although sargoides Macquart is currently considered incertae sedis (see below), this new species is placed in the genus Ocyptamus at the present time since a species name must contain a generic name and a specific epithet [Article 5.1, International Code of Zoological Nomenclature (1999)].

Figures

FIGURES 11–19. 11: Ocyptamus maximus Thompson sp. nov. [male paratype, INB003306083], metacoxae, sternum 1 and metaepisternum, posterior view. Note: Arrow indicates pile on metaepisternum. Red lines indicate the incomplete postmetacoxal bridge (=metathoracic epimera widely separated behind metacoxae). 12: Dioprosopa clavata (Fabricius) [female, INPA-DIP0000109], head and pleuron, lateral view. 13: Rhinoprosopa aenea (Hull) [male, ZFMK-DIP-00028705], head, lateral view. 14: Rhinoprosopa flavophylla Hull [male, USNMENT 00890787], head, lateral view. 15: Leucopodella incompta (Austen) [female, INPA-DIP0000104], head, lateral view. 16: Hermesomyia wulpiana (Lynch Arribálzaga) [male, USNM], head, lateral view. 17: Atylobaccha flukiella (Curran) [male, GFGM-MPEG0007], head, lateral view. 18: Leucopodella incompta [male, INBIO CRI001820341], habitus, dorsal view. Scale = 1 mm. 19: Atylobaccha flukiella [male, GFGM-MPEG0007], habitus, dorsal view. Scale = 1 mm.

FIGURES 20–31. 20: Toxomerus dispar (Fabricius) [female, INPA-DIP0000142], head, lateral view. 21: Toxomerus basalis (Walker) [male, ZFMK-DIP-00012165], head, frontal view. 22: Toxomerus paragrammus (Schiner) [male syntype, NHMW], head, lateral view. 23: Toxomerus marginatus (Say) [male, USNM], habitus, dorsal view. 24: Toxomerus pallipes (Bigot) [male, ZFMK], habitus, dorsal view. 25: Toxomerus dispar, epandrium and associated structures, dorsal view (from Thompson 1981). 26: Toxomerus floralis (Fabricius), epandrium and associated structures, dorsal view (from Thompson 1981). 27: Syrphus conjunctus Wiedemann [male, CNC_Diptera209347], head, lateral view. 28: Ocyptamus maximus Thompson sp. nov. [male paratype, INB003306083], head, dorsal view. Scale = 1 mm. 29: Ocyptamus sp., O. lepidus species group, female, habitus, dorsal view, by Gil F. G. Miranda. 30: Ocyptamus sp., O. callidus species group [female, INPA-DIP0000171], habitus, dorsal view. Scale = 2 mm. 31: Ocyptamus aff. micropyga, O. lepidus species group [male, INPA-DIP0000267], epandrium and associated structures, ventral view.

FIGURES 32–37. 32–35: Ocyptamus maximus Thompson sp. nov. [male holotype, INB003309582]. 32: habitus, lateral view. Scale = 5 mm. 33: habitus, dorsal view. Scale = 5 mm. 34: head, frontal view. Scale = 1 mm. 35: Sterna 1 and 2, ventral view. Scale = 1 mm. 36–37: Ocyptamus maximus Thompson sp. nov. [female paratype, CE-UCLA/DS-1235]. 36: head, frontal view. 37: habitus, lateral view.