Phytomyza (Ptochomyza) impunita, Lonsdale, 2015

Lonsdale, Owen, 2015, A new Afrotropical species of Phytomyza in the subgenus Ptochomyza (Diptera: Agromyzidae), African Invertebrates 56 (3), pp. 637-637 : 638-640

Phytomyza (Ptochomyza) impunita sp. n.

Figs 1–10

EtYmologY: The specific epithet is Latin for “free”, referring to its collection localitY in the Free State province of South Africa.

Description ( Figs 1–3 ):

Wing length 1.8–2.1 mm (♂), 2.1–2.4 mm (♀). EYe height divided bY gena height: 2.2– 2.3. Scutum covered with light brownish-grey pruinosity.Arista bare, less than twice the length of the antenna, with basal half slightlY thickened.First flagellomere small, slightlY longer than high, with anterodorsal corner angulate. Orbital plate raised, becoming more prominent anteriorly where it becomes strongly enlarged parafacial, which conceals base of antenna (viewed laterally). Epistoma relatively large, not noticeably delimited from soft face. Mouthparts relatively small, clypeus narrow and recessed. ChaetotaxY: Vibrissa short, difficult to distinguish from one or two stronger anterior genal setae. Two ori, two ors; sometimes three ori on one side. Postvertical and ocellar setae approximately as long as ocellar tubercle. One to two irregular rows of proclinate orbital setulae. Two notopleural setae, closely spaced on posterior half of notopleuron and nearly equidistant from lateral margin. Three dorsocentral setae, strongly decreasing in height anteriorly; sometimes fourth postsutural dorsocentral evident anteriorly. Acrostichal setulae in two to four scattered rows on anterior half of scutum (i.e. anterior to base of third dorsocentral); intra-alar setulae sparse, nearly absent posterior to third dorsocentral.

Coloration: Setae black to dark brown. Head yellow in base colour, sometimes light Yellow, with face, parafacial, gena and postgena alwaYs light Yellow to whitish; first flagellomere and mouthparts deeper Yellow to orange; clYpeus light Yellow with lateral arms darker yellowish orange; ocellar tubercle narrowly dark brown with centre paler and posterior region (including base of postvertical) yellow; posterolateral corner of frons with narrow spot extending from eye margin to medial base of inner vertical seta, proceeding posteriorly as thin line to back of head and extending in a straight vertical line to side of foramen; remainder of eye broadly surrounded by yellow; back of head brown with outer margin broadly yellow. Scutum yellow with faint greyish tint and with three dark stripes: anteromedial stripe narrow, widening at anterior margin, posteriorly ending at midpoint of scutum, and often faded in region just anterior to transverse suture; paired intra­alar stripes long, narrow, dark brown, floating, tapering posteriorlY; also with very narrow, faded postsutural supra-alar stripe attaining posterior margin of scutum; postpronotum with light-brown anterior spot reaching base of seta. Scutellum yellow with greyish tint. Metanotum yellow with posteroventral corner of katatergite, ventral half of anatergite and mediotergite dark brown. Pleuron mostly yellow with greYish tint; anepisternum with narrow, oblique, brown, ill­defined anteromedial to ventromedial stripe, with region anterior to stripe slightly paler; katepisternum paler with dark-brown ventral spot not reaching base of seta; anepimeron with brown to dark-brown stripes on anterior half; meron dark-brown with dorsum yellow. Legs yellow with base of coxae brownish; femora sometimes with brownish tint (possibly an artifact of preservation). Wing clear. Calypter margin and hairs brown. Halter yellowish white with apical surface of knob light brown. Abdomen mostly yellow; male with brownish, ill­defined dorsomedial stripe from tergite (1) 2–6, sternite 8 entirely yellow, epandrium with very narrow double stripe dorsally; female abdomen similarly yellow with stripe from tergites (1) 2–6, and with oviscape dark brown.

Male genitalia: ( Figs 4–10 ) Epandrium as wide as high, length approximatelY ⅔ height; dorsomedial region above anus bulging. Cercus small, finger­like. SurstYlus small, fully fused to epandrium, not evident. Phallapodeme (not illustrated) long, dark, rod-like. Hypandrium narrow with small triangular apodeme apically; arms broadly arched; two setae on shallow rounded lobe that is distinct from surrounding membranous area. Postgonite broad and subrectangular with long, tapering base, and darker slightly produced apex; one seta and one empty socket on outer-distal surface. Phallus weaklY sclerotised, gracile. Phallophorus small, cYlindrical, flanked bY one pair of relatively dark, rod-like lateral lobes. Basiphallus consisting mostly of long, narrow, dorsal plate split on distal ⅔; fused to dorsal margin of phallophorus; base with left lateral arm wrapping around venter of shaft. Paraphallus small, lobate, membranous. Hypophallus absent. Mesophallus not evident. Distiphallus nearly as long as basiphallus, curled dorsally and tapered to apex, weakly sclerotised laterally along length. Ejaculatory apodeme with relatively broad base, short stem and broad subtriangular blade with very weak distal margin; sperm sac with one pair of small, irregular subcircular sclerites.

HolotYpe ♂: SOUTH AFRICA: Free State: Brandfort , Florisbad Res. Stat., 28°46.039'S, 26°04.234'E, 25–29.x.2010, A.H. Kirk-Spriggs, Malaise traps, Acacia savanna ( BMSA).

ParatYpes: Same data as holotYpe (19♂ 25♀, BMSA; 4♂ 4♀, CNC; 2♂ 2♀ BMNH; 2♂ 2♀ USNM) .

Figures

Figs 1–10.Phytomyza (Ptochomyza)impunita sp. n., photos:(1) female paratype, left lateral; (2) male holotype, dorsal; (3) same, left lateral. Figs 4–10: P. impunita paratype, male genitalia: (4) epandrium, posterior; (5) epandrium, left lateral; (6) sperm pump; (7) hypandrium, ventral; (8) left postgonite, left lateral; (9) phallus, left lateral; (10) phallus, ventral.