Megaselia ischnopodae Disney, 2019

DISNEY, R. Henry L. & COMPTON, Stephen G., 2019, A new species of Megaselia Rondani (Diptera: Phoridae) associated with one sex of a dioecious fig tree in Thailand, Fragmenta Faunistica 62 (1), pp. 47-53 : 48-52

Megaselia ischnopodae Disney n. sp.

( Figs 1–24 )

Diagnosis. In Borgmeier’s (1967) key to Group VIII of Indo-Australian Megaselia it runs to couplet 14 lead 2 and to M. patelipya Borgmeier. However the figure of its hypopygium immediately excludes this species. At least five other species from elsewhere or subsequently described from Australasia will also run to this same couplet and lead. However, unlike M. patelipya they all have a dark brown thorax, darker legs and/or the hypopygium has hairs only.

Male. Frons as Fig. 1, with dense fine microsetae, with lower supra-antennal bristles clearly shorter and finer than upper pair and the anterolateral bristles higher on the frons than the antials. Antennae, palps and proboscis as Fig. 2 . Postpedicels with subcutaneous pit sensillae ( Fig. 3 ). Cheek with 3 bristles and jowl with 2 that are longer and more robust. Thorax mainly yellow, with bare mesopleuron, 2 notopleural bristles each side and no notopleural cleft ( Fig. 4 ). Scutellum with a minute hair and a pair of bristles each side ( Fig. 5 ). Abdominal tergite 2 yellow in anterior two thirds, rest brown except T5 and T6 tend to be paler. Venter pale with hairs on segments 3–6, but those on 3 and 4 are small and few in number. Hypopygium as Figs 6–9 , the epandrium having hairs and one bristle each side and the left hypandrial lobe is vestigial. The legs are yellow apart from a dark tip to hind femur. Front tarsus with posterodorsal hair palisades on segments 1 to 4 and 5 longer than 4 ( Fig. 10 ). Dorsal hair palisade of mid tibia extends about 0.7 times it length. Hind femur as Fig. 11 . Wings ( Fig. 12 ) 1.1–1.2 mm long, costal index 0.39–0.40, costal ratios 3.8–3.9: 1.7–1.8: 1. Tip of vein Sc free. Costal cilia 0.05 mm long. No hair at base of vein 3. With 2 axillary bristles, the outer being 0.08 mm long. Haltere with pale stem and brown knob ( Fig. 5 ).

Female. Head as male but with smaller palps and a larger proboscis ( Fig. 13 ). Thorax as male. Abdominal tergites 1–6 as Fig. 14 . Tergite 7 as Fig. 15 and tergite 8 and end of abdomen as Fig. 16 . Sternite 7 and lobes at rear of sternum 8 as Fig. 17 . Furca as Fig. 18 . Dufour’s crop mechanism as Fig. 19 . Wings as Fig. 20 , the costal index being 0.41 and the costal ratios 5.7– 5.9: 2.6–2.7: 1. Otherwise as male.

Puparia. Only moderately sclerotized ( Fig. 21 ). Anterior cap as Fig. 22 and rear end as Fig. 23 . Left eclosion plate as Fig. 24 .

Material examined. Holotype male, Thailand, Erawan National Park , Erawan Waterfalls , March 2018, reared from male figs of Ficus ischnopoda Miq. S. G. Compton ( UCZM, 6-45 ). Paratypes 4 males, 5 females as holotype. 7 puparia .

Etymology. Named after the fig species.

Figures

Figs 1–4. Megaselia ischnopodae n. sp. male: 1 – frons, 2 – antennae, palps and proboscis, 3 – postpedicel, 4 – left propleuron, notopleuron and mesopleuron.

Figs 5–12. Megaselia ischnopodae n. sp. male: 5 – left side of scutellum and haltere, 6–8 – left side of hypopygium, 9 – right side of hypopygium, 10 – front tarsus, 11 – hind femur, 12 – wing.

Figs 13–16. Megaselia ischnopodae n. sp. female: 13 – palp and proboscis, 14 – abdominal tergites 1–6, 15 – tergite 7, 16 – tergite 8 and end of abdomen.

Figs 17–20. Megaselia ischnopodae n. sp. female: 17 – sternite 7 and rest of abdomen, 18, – furca, 19 – Dufour’s crop mechanism (anterior end to right), 20 – wing.

Figs 21–24. Megaselia ischnopodae n. sp. puparium: 21 – general appearance, 22 – anterior cap, 23 – rear end, 24 – left eclosion plate.