Fergusonina thornhilli
Creators: name: Nelson, Leigh A.
name: Scheffer, Sonja J.
name: Yeates, David K.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Fergusoninidae
Fergusonina
Fergusonina thornhilli

description: Fergusonina thornhilli Nelson and Yeates sp. nov.
(Figs 1, 4 a–g, 7a–c)
Holotype. 3. AUSTRALIA. New South Wales: south of Abercrombie River (-33.928139°, 149.350111°, elev. 712 m), A.H. Thornhill, 6.xii.2010, from terminal leaf bud gall collected from E. dalrympleana.
Paratypes. 1 3, 3 Ƥ. All same label data as holotype (dried type material lodged: ANIC, Canberra).
Diagnosis. Adult. Small (average wing length 2.94 mm), second antennal segment dark brown; mesopleuron with black marking; thorax yellow with darkened patches and vittae on the mesonotum. Puparium. Puparium bearing dorsal shield comprising two heavily sclerotised patches.
Description. Adult (Fig. 4 a–g, Table 1). Head as in Figs. 5 a and b. General colour yellow with black markings where indicated and on abdominal tergites; basal segment of arista light brown, second antennal segment dark brown; eyes reddish; ocellar triangle black; anterior wall of thorax between postpronotal lobes with a pair of black fused ‘spots’ visible from the dorsal surface; darkened patches on the postpronotal lobes and vittae on the margin of the supraalar area posterior to the transverse suture, anterior to the posterior supraalar seta and medial to the anterior supraalar seta, additional medial vitta (often less distinct or absent) fused at the anterior margin with the former vitta (forming an inverted ‘V’ shape) lateral to dorsocentral seta and anterior to the intraalar seta; very feint, small markings sometimes present medial to the former posterior to the suture; scutellum yellow; subscutellum dark brown; mesopleuron with brown-black marking (band) extending from anterior margin of mesopleuron posteriorly to large differentiated mesopleural seta; abdominal tergite 1 yellow, tergites 2–4 with anterior two-thirds grey-brown and remainder yellow; dark markings on tergites 2–4 divided in midline with size of division decreasing posteriorly and thickness of marking tapering medially; anterior third of tergite 5 dark, remainder yellow; abdominal sternites yellow; male epandrium light brown.
Wing (Fig. 5 e, Table 1) distinctly light grey in colour; broadly elongate oval; costa bearing differentiated setae to little beyond R2 + 3; costa very feint beyond R4 + 5; veins R2 + 3 and R4 + 5 divergent to mid-length, parallel beyond; anterior cross vein r-m short, posterior cross vein slightly angled mid-length.
Setation (all setae black). One pair of short postocellar setae 0.8× length of largest orbital seta; ocellar setae half length of postocular setae; one pair of short inner vertical setae, about same length as postocellar setae; one pair of long outer vertical setae about two times length of postocellar setae; two pairs reclinate orbital setae, posterior longest, as long as inner vertical setae; parafacial setae short, setae on genae numerous, 16–21 per side; one pair of vibrissae, three times the length of the parafacial setae; mesonotum with many short setae; acrostichal seta and intraalar seta differentiated, intraalar seta 1.2× length of achrostichal seta and considerably shorter than posterior dorsocentral and posterior supraalar setae; posterior two dorsocentral setae differentiated, with posterior seta longest; posterior supraalar setae long, about same length as posterior dorsocentrals (about 8× length of undifferentiated mesonotal setae) (following measurements ditto); anterior supraalar seta shorter (3×), a little shorter than presutural seta (as long as intra-alar seta), anterior notopleural seta (1.5× length of supraalar seta), about same length as posterior notopleural seta; differentiated humeral seta as long as anterior notopleural seta; humeral lobe with 3– 5 setae (one long and 2–4 short setae); mesopleuron with 12 setae (one long, as long as differentiated humeral seta, and remainder shorter); sternopleuron with 1 long differentiated seta posteriorly and a row of 4–6 undifferentiated setae along dorsal margin; scutellum with two pairs of marginal setae comprising a pair of very long apical setae, and a pair of subapical setae about 0.5× length of apical setae.
Abdominal tergites with black setae, longer on posterior and lateral margins of each tergite, longest on margins of tergite 5 (as long as subapical scutellar setae); sternites with short black setae in two submedial fields: sternite 2 (6–7 on each field), 3 (7–8 on each field), 4 (9–12 on each field) and 5 (20–25 on each field). On sternite 5 there is a larger differentiated seta lateral to the submedial field of seta.
Male postabdomen (Fig. 7 b and c). Epandrium oval-shaped with 19–20 pairs of setae (including one pair of large differentiated dorsal setae); telomeres distally rounded with 3 small setae on inner surface apically; cerci small and articulating with the ventral margin of the epandrium; postgonites with one large distal tooth and approximately 7 submedial setae.
Variation. The medial mesonotal vitta vary from being almost completely fused anteriorly with the lateral mesonotal vitta and dark in colour, to entirely absent. The feint markings centrally on the mesonotum, medial to the aforementioned vitta, are even lighter in colour and observed less often. Female abdomen similar to male except for elements of the ovipositor (segment 6 to end; Fig. 7 a). Segment 6 orange with 6 dorsal and 6 ventral setae mainly along posterior margin with some scattered; segment 7 black with 6 scattered ventral setae and 4 dorsal setae.
Mature third instar larva. Unknown.
Puparium (Fig. 4 g). Puparium barrel-shaped, smooth, brown, annulated, bearing dorsal shield comprising two heavily sclerotised patches. Measurements as in Table 1.
Etymology. This species is named after collaborator and friend Andrew Thornhill, who collected the galls from which this species is described.
description: Published as part of Nelson, Leigh A., Scheffer, Sonja J. & Yeates, David K., 2011, Three new species of Fergusonina Malloch gall-flies (Diptera: Fergusoninidae) from terminal leaf bud galls on Eucalyptus (Myrtaceae) in south-eastern Australia, pp. 36-48 in Zootaxa 3112 on pages 44-47, DOI: 10.5281/zenodo.207304