Cabamofa orientalis, Jaschhof & Ševčík, 2019

Jaschhof, Mathias & Ševčík, Jan, 2019, Cabamofa orientalis sp. nov. from Thailand, congeneric with C. mira Jaschhof from Costa Rica (Diptera: Bibionomorpha: Sciaroidea incertae sedis), Zootaxa 4576 (2), pp. 392-394 : 392-394

Cabamofa orientalis sp. nov. ( Figs 1–6 )

Diagnosis. The new species fits largely the description of Cabamofa by Jaschhof (2005), with the exception of the following peculiarities in the wing ( Figs 2, 4 ): vein Rs is situated basal (not distal) of M 4; R 1 joins the costa at (not clearly beyond) the midpoint of wing; and the stem of M 1+2 is completely absent (not even present as short vestige apically). These characters alone differentiate C. orientalis from C. mira ( Jaschhof 2005: figs 24–25). Other distinctions concern male genitalic structures, as follows (see Amorim & Rindal 2007: figs 44–47 for genitalic characters of C. mira ). The ninth tergite has a convex, broadly rounded (rather than concave, V-shaped) posterior edge and no posterolateral lobes ( Fig. 6 ); the gonostylus is not trilobate (as it is in C. mira ) and bears a small, blunt-ended tooth medially (which is absent in C. mira ) ( Fig. 5 ); and the ejaculatory apodeme is not furcate apically (as it is in C. mira ) ( Fig. 5 ).

Other male characters. Body length 2.8 mm. Head. Clypeus non-setose. Scape slightly larger than pedicel, both lighter than flagellum. Fourth flagellomere cylindrical, with short neck, node 2.5 longer than wide, with irregular cover of fine setae whose lengths equal the flagellomeral width, interspersed with a few larger setae arising from distinct sockets ( Fig. 1 ). Compound eyes touching at vertex, eye bridge about 7 ommatidia long dorsally. Palpus with 5 setaebearing segments, third segment conspicuously swollen, with sensory pit, fifth segment conspicuously long and thin ( Fig. 3 ). Legs. Lengths of coxae relative to thoracal height: forecoxa, 0.8, midcoxa, 0.6, hindcoxa, 0.5. Edge of foretibial anteroapical depression with comb of about 15 setae. Mid- and hindlegs broken behind coxae. Claws small, strong, crescent-shaped, toothless. Empodia small, barely claw-long. Genitalia. Gonocoxae largely merged ventromedially except for a wide, shallow emargination medioposteriorly; lateral setae large, medial setae mostly smaller; a triangular portion below the emargination non-setose; a pair of small, setose protuberances inside (not illustrated); dorsal apodemes short ( Fig. 5 ). Gonostylus with narrow, stem-like base; apical portion somewhat angular, ventrodorsally flattened, with long setae laterally; a bulbous, rounded lobe medially covered with numerous short, thick setae ( Fig. 5 ). Parameres merged to form a subrectangular, weakly sclerotized plate (tegmen); parameral apodemes slender ( Fig. 5 ). A subtriangular area of fine aedeagal teeth near the tegminal edge ( Fig. 5 ). Ejaculatory apodeme as long as tegmen, sclerotized, slightly broadened apically, apex faintly contoured ( Fig. 5 ). Cerci small, setose, closely associated with hypoproct (the tenth tergite of Amorim & Rindal 2007: fig. 47), the latter large, slightly bilobed, smooth, microtrichose ( Fig. 6 ).

Female and preimaginal stages unknown.

Etymology. The name refers to the Oriental distribution of this species.

Type material. Holotype dissected and mounted on microscope slide in Canada balsam. Male, Thailand, Kanchanaburi, Khuean Srinagarindra National Park , tourist center, 14°38.136´N / 98°59.837´E, 210 m, 11–18.vii.2008, Somboon & Chatchawan ( TIGER sample T3432) (in Queen Sirikit Botanic Garden, Chiang Mai, Thailand).

Discussion. Jaschhof (2005) postulated a sistergroup relationship between Cabamofa and Rogambara on the basis of two synapomorphies: the presence of holoptic eyes and the absence (loss) of ocelli. As recognized here, other synapomorphous characters supporting this clade are the foreshortening of the medial fork (i.e., the fork made of M 1 and M 2 is shorter than the stem M 1+2) and the merging of the parameres into a plate (tegmen). In distinction from Rogambara (character states in parentheses), Cabamofa have five setae-bearing palpal segments (three segments, the first and second reduced); the anepisternum is of normal size (enlarged); the pattern of tibial spurs is 1:2:2 (1:1:1); and the female cercus is two-segmented (one-segmented) ( Jaschhof 2005). Further distinctions are found in the male genitalia: the gonocoxites are largely merged ventromedially (largely separate); and hypoproct and cerci are closely associated with each other as well as with the ninth tergite (all these structures clearly separate).

Figures

FIGURES 1–6. Cabamofa orientalis sp. nov., male holotype. 1: Fourth flagellomere, lateral. 2: Wing, dorsal. 3: Palpus, ventrolateral. 4: Base of wing, dorsal. 5: Genitalia, ventral, dorsal parts omitted. 6: Ninth tergite with hypoproct and cerci indicated, dorsal. Scale for 1 and 3, 0.05 mm, for 2, 0.50 mm, for 4, 0.20 mm, for 5 and 6, 0.10 mm.