Teratomyza ismayi, Bayless, 2022

Bayless, Keith M., 2022, A New Species of Teratomyza, the First Fern Fly from New Guinea (Diptera, Teratomyzidae), Records of the Australian Museum (Rec. Aust. Mus.) 74 (1), pp. 13-18 : 14-16

Teratomyza ismayi sp. nov.

urn:lsid:zoobank.org:act:E4023362-4493-4A6C-B72C-04A2972AFDBD

Figs 1–4

Holotype ♂, PAPUA NEW GUINEA, Oro (or Northern) Province: Myola , 2080 m, 4.vi.1984, J. W. Ismay, forest ( AM K.300570) . Paratypes. PAPUA NEW GUINEA, Oro (or Northern) Province : 1♂, 1♀, same locality as holotype, except 2080–2200 m, 1.iv and 3.iv.1984 ( AM K.580252 ♂, K.580254 ♀) . PNG, Central Province: 1♂, Aieme River , 11.v.1986, J. W. Ismay ( AM K.580253) ; 1♀, 5 km S of Sirinumu Dam , 21.ix.1986, J. W. Ismay ( AM K.580255) .

Diagnosis

Teratomyza ismayi is differentiated from other Teratomyza most readily by the following combination of characters: wing membrane markings relatively diffuse and indistinct ( Fig. 1A ); R 2+3 thickened and sinuous at midlength, with single undulation approximating costa; r–m crossvein more than twice as long as dm–m; M 1+2 arched posteriorly proximal to r–m insertion, so that cell br is much wider than dm; head broadly depressed so that the eye is much longer than high in profile ( Fig. 1C ); single series of setulae present on gena (cheek sensu D. K. McAlpine, 2012); postvertical (= paravertical) seta absent; one katepisternal seta ( Fig. 1B ). In addition, the form and armature of the surstylus is distinctive in the male ( Fig. 2 ). The compressed tarsal processes ( Figs 3 , 4 ) are relatively small and few, but these structures are only detectable under high magnification and are not adequately known for some species groups.

Description (♂, ♀)

Coloration. Postfrons dull tawny, becoming paler anteriorly, with dark brown spot at each anterolateral angle, otherwise unmarked; face dull greyish, paler ventrally; dark brown zone present medial to posteroventral margin of eye, gena and postgenal region pale yellow-white. Antenna grey-brown. Thorax with complete horizontal mid-pleural brown-black stripe from middle of proepimeron to base of halter; thorax dorsal to this stripe brown, ventral to stripe yellow-white; mesoscutum with pair of longitudinal intradorsocentral yellow stripes. Wing membrane smoky-brown, slightly darker apically and anteriorly to R 4+5, with nebulous whitish zones posteriorly to R 4+5 ( Fig. 1A ); veins (including CuA+CuP) brown, without evident paler zones. Halter predominantly dark brown. Legs pale yellowish; femora of most specimens indistinctly brown apically. Abdominal tergites brown, without markings.

Head broadly depressed; postfrons longer than broad; height of eye c. 0.6 of length; height of gena c. 0.27 of height of eye in profile; face apparently slightly raised on median line, oblique in profile; postocellar setae scarcely differentiated; ocellar setae small but usually distinct; postocular setulae scarcely extending mesad of outer vertical seta; genal setulae mostly in a single series ( Fig. 5 ), but one small seta usually present well below upper anterior vibrissa. Antenna porrect; segment 1 rounded, exserted, about as long as high in lateral view, setulose dorsally; segment 2 very short, setulose; segment 3 longer than high, broadly rounded distally; arista arising near mid length of segment 3, longer than rest of antenna, with long somewhat sparse pubescence extending to its apex. Palpus absent, not even vestige visible ( Fig. 6 ).

Thorax slightly elongate, 1.1 times as long at midline than width between notopleural lobes; mesoscutum, in profile, with very straight dorsal outline, anterior margin strongly angularly produced over occiput, extensively rather coarsely microtrichose; scutellum somewhat elongate, 0.9 times as long at midline than width of anterior dorsal margin, slightly convex, broadly rounded posteriorly, shining but coarsely microtrichose; subscutellum vestigial, reduced to a similar degree as Australian T. undulata ; the following thoracic setae present: two pairs of dorsocentrals, quite small presutural setae situated close to transverse suture, 1 + 1 notopleurals, one postalar, one pair of scutellars, situated laterally near mid-length of scutellum, one katepisternal; one to three small setulae situated in front of anterior dorsocentral setae; acrostichal or paramedian setulae absent; few humeral setulae present; few fine setulae near katepisternal seta. Fore femur with a series of fine, long posterodorsal setae and a series of posteroventral setae, one or two of which are larger than the posterodorsal ones ( Fig. 7 ); mid femur setulose, without larger setae; hind femur with setulae of various sizes and usually one larger preapical dorsal seta; mid tibia without apical spurs. Wing: R 1 thickened and closely approximated to costa on short region before mid-length; R 2+3 and R 4+5 preapically convergent, divergent apically; basal section of M 1+2 strongly arched so that second basal cell is much broader than first basal cell in this region; r–m at least twice as long as dm–m.

Male postabdomen. Epandrium extensively microtrichose with relatively few short setulae; surstylus large, almost obovate, rounded distally, with long setulae near posterior margin, no microtrichia, and with very small comb of approximately four blunt spinules on inner surface close on posterior margin; cercus small, setulae not very long and prominent.

Dimensions. Total length, ♂ 1.3–1.7 mm, ♀ 1.6–1.9 mm; length of thorax, ♂ 0.58–0.67 mm, ♀ 0.72–0.86 mm; length 16 Records of the Australian Museum (2022) Vol. 74 of wing, ♂ 1.6–2.2 mm, ♀ 2.1–2.7 mm.

Distribution. Only known from a small area in the Owen Stanley Ranges, mainland Papua New Guinea.

Etymology. In recognition of his contributions to acalyptrate Diptera research, in addition to the fact that he collected all known specimens, this species is named in honour of Dr John W. Ismay (Oxford University Museum of Natural History).

Figures

Figure 1. Teratomyza ismayi holotype. (A) Left wing, ventral side. (B) habitus, left lateral view. (C) Head, left lateral view. (D) Head, dorsal view. (E) Thorax, dorsal view.

Figure 2. Teratomyza ismayi male genitalia (A) external features, left lateral view.(B) right surstylus, internal view, illustrating armature.

Figure 3. Teratomyza ismayi, outer claw of left prothoracic tarsus of male.

Figure 4. Teratomyza ismayi, inner claw of left prothoracic tarsus of male.

Figure 7. Teratomyza ismayi sp. nov., right prothoracic leg of male, lateral view.

Figures 5–6. Teratomyza ismayi sp. nov. (5) proboscis and ventral edge of gena of male, anterolateral view; (6) part