Hamecamyia stuckenbergi, Gaimari, 2012

Gaimari, Stephen D., 2012, A new Afrotropical genus of Chamaemyiidae (Diptera: Lauxanioidea), African Invertebrates 53 (1), pp. 157-157 : 159-166

Hamecamyia stuckenbergi sp. n.

Figs 1–23

Etymology: It is with great pleasure that I name this species after the late South African GLSWHULVW %ULDQ 5R\ 6WXFNHQEHUJ, VSHFL¿FDOO\ KRQRXULQJ KLV ZRUN RQ /DX[DQLRLGHD.

Diagnosis: Head higher than long. Postocellar setae strong, convergent to cruciate. Ocellar setae strong, proclinate. Frons with 2 pairs fronto-orbital setae, with anterior seta closer to lunule than to posterior seta.Anterior edge of frons black along straight narrow OXQXOH.$QWHQQD \HOORZ,H[FHSW IRU VOLJKW GDUNHQLQJ GRUVDOO\ DQG D GDUN EURZQ DULVWD;¿UVW ÀDJHOORPHUH URXQGHG GLVWDOO\ ZLWK VPDOO VXEDSLFDO GRUVDO SURWUXVLRQ. 6FXWXP ZLWK SDLUV of vittae through intra-alar region, through anterior half of medial region, and through posterior half of dorsocentral region. Scutum with 2 strong postsutural dorsocentral setae, and lacking strong prescutellar acrostichal setae. Proepisternum, prosternum and mesopleuron lacking setae or setulae, except 2 strong katepisternal setae along upper edge. Wing hyaline, with subcostal cell white, with membrane darkened along costal cell to wing apex; veins brown, except pale humeral crossvein and veins Sc, R 1, Rs, basal half of R 2+3 and A 1 +CuA 2. Abdominal tergites 2–5 with paired diffuse brown longitudinal spots dorsally, coalescing to appear as diffuse abdominal stripes, and tergites 3–5 each with brown pruinose longitudinal strip laterally. In female: sternite 6 shiny dark brown, with series of long thick setulae fanning out around rounded posterior margin.

Description:

Male & Female.

Body length: male 2.7–4.6 mm, female 2.9–4.0 mm; silvery-grey pruinose, except as noted below.

Head ( Figs 2–4 ). 1.3–1.4× as high as long; 1.8–1.9× as wide as long; 1.3–1.4× as wide as high. Vertex with strong vertical setae, inner one slightly longer than outer one. Postocellar setae strong, convergent to cruciate. Ocellar triangle slightly raised, placed at vertex; with 1 pair short black divergent setulae (occasionally with supernumerary setula); ocelli on small ocellar tubercle (each side 0.2× width of frons), with sides subequal; anterior ocellus slightly larger than posterior. Ocellar setae strong (subequal to inner vertical seta), proclinate; separated by distance equal to distance between posterior ocelli; originating at level of anterior ocellus. Eye 1.0–1.1× as high as long; 4.5–6.5× as high as gena. Frons 0.4–0.5× width of head; 1.4–1.6× as wide as long; with lateral edges subparallel; U-shaped area around ocellar triangle with sparser pruinosity exposing dark groundcolour, not reaching eye margin laterally; lacking setulae posterior to level of anterior fronto-orbital setae, with upside-down U-shaped irregular row of setulae over lunule. Fronto-orbital area with 2 pairs reclinate fronto-orbital setae, with posterior seta equidistant between anterior seta and inner vertical seta, and with anterior seta slightly closer to lunule than to posterior seta; anterior edge of frons along lunule black, not reaching eye margin laterally. Lunule narrow, straight; slightly paler pruinose.Antenna \HOORZ-RUDQJH, H[FHSW ÀDJHOORPHUH Í ZLWK VOLJKWO\ GDUNHQHG VSRW DQWHULRU WR DULVWD, DQG DULVWD GDUN EURZQ; ÀDJHOORPHUH Í ()LJ. Ϭ) VOLJKWO\ ORQJHU WKDQ KLJK, URXQGHG GLVWDOO\ with small subapical dorsal protrusion ( Fig. 5 ); arista with distal segment 8–10× longer than basal. Face with short carina, sharpened ventrally and produced into round peg dorsally between antennal bases; with distinct antennal grooves. Parafacial narrow, 0.2 width of face; sides subparallel; extending indistinguishably into gena; with 1 or 2 strong genal setae in addition to row of 2–4 shorter subvibrissal setae. Clypeus small. Palpus yellow, cylindrical; with single strong distal seta in addition to sparse small setulae. Prementum small, partly devoid of pruinosity, displaying dark ground colour. Labellum pale yellowish with whitish hairs; pseudotracheal canals straight, not anastomosing.

Thorax ( Figs 1, 2 ). Scutum 0.9–1.2 mm long, 1.2–1.4× as long as wide, 3.6–4.1× as long as scutellum; vittate, with dark grey vitta through intra-alar region becoming brown at posterior end, with dark grey vitta through anterior half of acrostichal region coalescing with wider brown vitta in posterior half encompassing dorsocentral setae to posterior edge and extending through scutellum as dark grey vitta; setulose with 4 irregular rows between dorsocentral rows and 2 irregular rows between dorsocentral and intra-alar URZV, EXW ODFNLQJ VHWXODH LQ SRVWHULRU ¿IWK, H[FHSW IRU Í RU ƻ SDLUV RI VOLJKWO\ HQODUJHG prescutellar acrostichal setulae. Prescutellum present. Scutellum 1.5–1.7× as wide as long. Chaetotaxy: 0+2 dorsocentral setae, located in posterior half of scutum, anterior seta about 0.75 length of posterior seta; anterior to dorsocentral setae with 4 or 5 strong VHWXODH (ͱƻ EHLQJ SUHVXWXUDO; DOZD\V OHVV WKDQ ѿ OHQJWK RI DQWHULRU GRUVRFHQWUDO VHWD, PRVW RQO\ VOLJKWO\ ORQJHU WKDQ VXUURXQGLQJ VHWXODH), WKH ¿UVW RULJLQDWLQJ YHU\ FORVH WR anterior dorsocentral seta; 1 postpronotal seta, and 1–several small postpronotal setulae; 2 notopleural setae, in anterior and posterior corners, anterior one 2× longer than posterior one; 1 pre- and 1 postsutural supra-alar seta; 1 posterior intra-alar seta; 1 postalar seta; prescutellar acrostichal seta absent (see above regarding setulae); proepisternum and prosternum lacking setae or setulae; mesopleuron lacking setae or setulae, except 2 strong katepisternal setae along upper edge, with anterior seta about half size of posterior, and with several small setulae anterior to and below setae; two pairs scutellar setae, anterior seta 0.6 length of posterior seta.

Legs. Femora yellow apically; fore femur with row of 1–3 posterodorsal setae subapically, 3–5 posterior setae, 6 ventral setae; mid femur with row of 1–3 short anterodistal setae in distal part, 3 short anteroventral setae subapically, 2 posteroventral setae subapically; hind femur with no outstanding setae, posterior surface devoid of pruinosity; hind femur slightly enlarged relative to other femora, with fore femur slightly enlarged relative to mid femur. Tibiae brown with sparser grey pruinosity, except yellow proximally on fore tibia and proximally and distally on mid and hind tibiae; mid tibia ZLWK Í DSLFRYHQWUDO VSXU ÀDQNHG RQ HDFK VLGH E\ ͱ VPDOOHU VSXUV; KLQG WLELD ERZHG basally. Tarsi with fore tarsus brown, except dorsally with wide orange longitudinal strip through tarsomeres 1 and 5 and narrow strip through tarsomeres 2–4, and ventrally on tarsomeres 3–5; mid and hind tarsi yellow, except brown laterally on tarsomeres 2–5.

Wing ( Fig. 7 ). Length 2.9–4.0 mm; 2.5–2.8× as long as high. Hyaline; subcostal cell white; membrane darkened along costal cell to tip of vein R 4+5, or fading to M 1. Veins brown, except pale humeral crossvein, and pale veins Sc, R 1, Rs, basal half of R 2+3 and A 1 +CuA 2; vein A 1 present as fold, extending beyond tip of short A 1 +CuA 2; veins R 2+3, R 4+5 and M 1 parallel in distal half of wing. Crossvein r–m located at about 0.4 wing length, and at halfway point of discal medial cell length. Discal medial cell 4–5× as long as crossvein dm–cu. Vein CuA 1 ending slightly before wing margin, but reaching wing margin as fold; apical section 1.8–3.2× as long as crossvein dm–cu. Haltere white.

Abdomen ( Fig. 8 ). Tergites uniformly setulose, except setulae slightly enlarged along posterolateral margins of syntergite 1+2 and tergites 3–5, and along entire posterior margins of tergites 4 and 5; syntergite 1+2 and tergites 3–5 each with paired diffuse brown longitudinal spots dorsally, coalescing to appear as diffuse abdominal stripes; tergites 3–5 each with brown pruinose longitudinal strip laterally, not reaching posterior edge. Sternites 1–5 ( Fig. 11 ) nearly identical in males and females; sternite 1 a thin transverse strip with anteriorly-directed lateral wings; sternite 2 slightly wider than long, with anterior margin invaginated; sternites 3–5 subequal, slightly narrower than sternite

2, slightly longer than wide; tergites 4–5 with longitudinal row of 6–10 slightly enlarged setulae along lateral margin; sternites with setulae strongest laterally and posteriorly, particularly strong on sternite 5.

Male pregenitalic segments. Tergites telescoped under tergite 5. Tergite 6 ( Fig. 12 ) saddle-shaped, with medial invagination on anterior and posterior margins; usually lacking setulae, but occasionally with 2–4 setulae on posterior margin. Tergites 7 and 8 ( Figs 12, 13 ) closely associated as syntergite 7+8, but not fully fused (fused only on right side); tergite 7 asymmetrical, as thin transverse band produced and elongated on left side, closely associated at tip with small sternite 6 ( Figs 13, 14 ), also asymmetrically placed to left side; sternite 7 ( Fig. 14 ) slightly narrower than sternite 5, about 3× wider than long; tergite 8 narrow, saddle-shaped, tapering laterally.

Female pregenitalic segments ()LJV 9, ÍƟ). 7HUJLWH Ϭ DERXW ѿ OHQJWK RI WHUJLWH ƽ; ZLWK transverse series (not in regular row) of long thick setulae; laterally shiny dark brown, ODFNLQJ SUXLQRVLW\. 6WHUQLWH Ϭ VOLJKWO\ ORQJHU WKDQ ZLGH, DERXW Ҁ ZLGWK RI VWHUQLWH ƽ; margin rounded posteriorly; with series of long thick setulae fanning out around rounded posterior margin; shiny dark brown, lacking pruinosity.

Male terminalia ( Figs 12, 13, 15–18 ). Epandrium broadly rounded with no surstylar lobes, slightly elongated; with series of setae along posterodorsal part; with small VHWDH DORQJ URXQGHG GLVWDO SDUW. &HUFL ODUJH, ZLWK GHQVH WLQ\ VHWXODH EDVDOO\ DQG ¿QH longer setulae distally. Subepandrial sclerite U-shaped, articulated at anterior corners with posterior corners of hypandrium. Hypandrium slightly longer than wide; lateral arms bowed out, widest at posterior third; in lateral view, gently curved, broadened at anterior tip. Pregonite short, tapering to blunt tip with 2 subapical setulae. Postgonite elongate, 2× length of pregonite; tapering to blunt tip with tiny setulae on dorsomedial VXUIDFH WKURXJK GLVWDO Ҁ. 3KDOODSRGHPH ODUJH, ODWHUDOO\ ÀDWWHQHG; LQ ODWHUDO YLHZ, QHDUO\ 2× as long as high, dorsal surface gently sloping. Phallus elongate; in dorsal view, parallel sided; in lateral view, basiphallus dorsally expanded, and gently curved through distiphallus to blunt tip.

Female terminalia ( Figs 9, 10 , 19–23 ). Tergite 7 shiny dark brown, lacking pruinosity; medially folded with left and right halves at acute angle to each other; posterior edge RI HDFK KDOI IROGHG EDFN LQWR LQWHUQDO, DQWHULRUO\-GLUHFWHG ÀDQJH EHDULQJ VHYHUDO VPDOO setulae and connected to distal membrane at posterior (physically anterior) edge, with ÀDQJH ca 2× as long as wide and extending anteriorly well beyond anterior edge of tergite. Sternite 7 shiny light brown, lacking pruinosity; medially separated into two halves held at 90° angle to each other, with each about 2× as long as wide; posterior HGJH RI HDFK KDOI IROGHG EDFN LQWR LQWHUQDO, DQWHULRUO\-GLUHFWHG ÀDQJH EHDULQJ VHYHUDO small setulae and connected to distal membrane at posterior (physically anterior) edge, ZLWK ÀDQJH DERXW ƻî DV ORQJ DV ZLGH DQG H[WHQGLQJ DQWHULRUO\ EH\RQG DQWHULRU HGJH RI sternite. Distal segments fully inserted within segment 7, with no parts exserted in any pinned specimens. Tergite 8 medially divided into two longitudinally elongated sclerites, each about 5× as long as wide. Sternite 8 not evident. Epiproct small, medially divided, as long as wide, bearing several tiny setulae. Hypoproct about 2.5× as long as basal width, tapering distally; bearing numerous tiny setulae, including pair of distal elongated setulae. Cerci pad-like, elongated, bearing numerous tiny setulae; closely associated along dorsal margins, opening more widely ventrally. Spermathecae 2+2, elliptical; strongly sclerotised, with each pair connected via sclerotised common entrance; short spermathecal ducts originating together on dorsal surface of genital chamber. Simple central accessory gland originating in front of spermathecal duct origins; paired lateral accessory glands not observed, but may be present.

+RORW\SH:ƃ ()LJ. Í; JOXHG WR VLGH RI SLQ,H[FHOOHQW FRQGLWLRQ) 6287+$)5,&$: KwaZulu-Natal: “ RSA, Natal 1760m / 75km WSW [error, 62 km 274°] Estcourt / Cathedral Pks. [Peak] For[est]. Sta[tion]. [28.968166°S 29.238465°E] / 21–31.XII.[19]79 S. & J.Peck”, “ CHAMAEMYIIDAE / S.D. Gaimari / Specimen # / 7579”, ³+RORW\SXV ƃ / Hamecamyia / stuckenbergi / Gaimari” [red label] (CNC).

Paratypes: SOUTH AFRICA: KwaZulu-Natal: ƻƟƃ Í8Ƃ VDPH ODEHO GDWD DV KRORW \SH (ÍƟƃ ÍƟƂ &1&; 4ƃ Ƃ &6&$; ƻƃ ƻƂ 106$; 4ƃ Ƃ 8610) .

Biology:All specimens were collected in late December at 1760 m elevation in Cathedral Peak, which is in the Drakensberg section of the Great Escarpment. The collecting locality situates in the montane grasslands of the lower southern slopes, which is also characterised by presence of Protea and Podocarpus . As with other Chamaemyiini for which larval biology is known, larvae of this species likely feed on mealybugs in grasses.

Figures

Figs 1–4. Hamecamyia stuckenbergi gen. et sp. n.: (1) habitus, lateral view, holotype SDG7579; (2) thorax and head, dorsal view, paratype female SDG7582; (3, 4) head, paratype female SDG7582, anterior (3) and lateral (4) views. Scale bars = 0.5 mm.

Figs 5–10. Hamecamyia stuckenbergi JHQ. HW VS. Q.: (ƽ, Ϭ) SDUDW\SH Ƃ 6'*7ƽ77, VXEDSLFDO SURWUXVLRQ RQ DQWHQQDO ¿UVW ÀDJHOORPHUH,PHGLDO YLHZ (ƽ) DQG DQWHQQDO ¿UVW ÀDJHOORPHUH,PHGLDO YLHZ (Ϭ);(7) ZLQJ, YHQWUDO YLHZ,SDUDW\SH ƃ 6'* 7ƽϬϬ;(8) DEGRPHQ,GRUVDO YLHZ,SDUDW\SH Ƃ 6'*7ƽ7Ɵ; (9) DEGRPLQDO WLS,SRVWHULRU YLHZ,SDUDW\SH Ƃ 6'*7ƽ94; (ÍƟ) VWHUQLWH Ϭ, YHQWUDO YLHZ,SDUDW\SH Ƃ 6'*7ƽ94. 6FDOH bars: Fig. 5 = 0.01 mm; Fig. 6 = 0.05 mm; Figs 7, 8 = 0.5 mm; Figs 9, 10 = 0.1 mm.

Figs 11–18. Hamecamyia stuckenbergi gen. et sp. n., male paratype SDG7559 (dissection 1393) (12–18 oriented with posterior end to right): (11) abdomen, ventral view; (12) tergites 6–8 and epandrial complex, dorsal view; (13) tergites 7–8, sternite 7, and epandrial complex, lateral view; (14) sternites 6–7, ventral view; (15) hypandrium, dorsal view; (16) subepandrial sclerite, ventral view (inside epandrium); (17) aedeagal complex, lateral view; (18) phallus, lateral view. Abbreviations: h – hypandrium; pa – phallapodeme; pog – postgonite; prg – pregonite; s6 – sternite 6; s7 – sternite 7; t6 – tergite 6; t7 – tergite 7; t8 – tergite 8. Scale bars = 0.2 mm.

Figs 19–23. Hamecamyia stuckenbergi gen. et sp. n., female paratype SDG7586 (dissection 1394), except Fig. 23 female paratype SDG7594 (dissection 1395) (19–22 oriented with posterior end to right): (19) sternite 7, ventral view, and tergite 7, dorsolateral view (view is relative to tergite 7 being split GRUVDOO\ LQWR OHIW DQG ULJKW KDOYHV);(ƻƟ) LQWHULRU ÀDQJHV RI VWHUQLWH 7, GRUVDO YLHZ, DQG WHUJLWH 7 (YLHZ internal, relative to tergite 7 being split dorsally into left and right halves); (21) tergite 8, epiproct, and cerci, dorsal view; (22) hypoproct and cerci, ventral view; (23) spermathecae and one accessory gland, dorsal view. Abbreviations: e – epiproct; h – hypoproct; s7 – sternite 7; sf ± LQQHU ÀDQJH RI sternite 7; t7 – tergite 7 (split); tf ± LQQHU ÀDQJH RI WHUJLWH 7; t8 – tergite 8. Scale bars: Figs 19–22 = 0.2 mm; Fig. 23 = 0.1 mm.