Megaselia serrata (Wood)

Disney, R. H. L. & Russell-Smith, A., 2014, Additions to the British list of Megaselia Rondani (Diptera: Phoridae), including two new species, from the crowns of ancient pollarded trees, Journal of Natural History 49 (25), pp. 1599-1626 : 1609

Megaselia serrata (Wood)

( Figures 9–17 )

Phora serrata Wood 1910, p. 150 (male)

The male of this species is covered by the key to British species ( Disney 1989). The hitherto-unknown female is described below.

Female

Head similar to male but the greyish-brown labrum is 1.1–1.2 times as wide as the diameter of the postpedicel (which, like that of the male, lacks subcutaneous pit sensilla [SPS] vesicles). In the male, the labrum is only about 0.08 times as wide as a postpedicel. Labella paler, with submarginal light brown bands above and very few bristles reduced to small spinules below at tips. Otherwise head similar to male. Thorax similar to male, in having three bristles on notopleuron, seven to 10 hairs on mesopleuron, and scutellum with an anterior pair of small hairs and a posterior pair of bristles. Abdominal tergites brown and as in Figures 9 and 10 . Terminal segments as in Figure 12 . Venter grey, and with hairs below segments 3–6. Sternite 7 brown and as in Figure 12 . Posterolateral lobes at rear of sternum 8 tinged brown and with three hairs at rear margin and several smaller ones further forward ( Figure 13 ). Cerci brown and as in Figure 11 . Furca pale grey and outline variable in relation to angle of view ( Figures 14–16 ). Dufour’ s crop mechanism seemingly absent. Legs similar to male but the hind femur lacks the hooked spines beneath the basal half, where the hairs are subequal to the anteroventral hairs of the distal half. The dorsal hair palisade of mid tibia, as in male, extends about two thirds of length. Wing as male except 1.4–1.5 mm long. Costal index 0.40. Costal ratios 4.4:1.7:1. Costal cilia (of section 3) 0.07 mm long. Vein Sc not reaching vein 1 and with no hair at base of vein 3. With two unequal axillary bristles, the outer being longer than the costal cilia. Otherwise wing and haltere as male.

Figures

Figure 9. Megaselia serrata female, details of abdomen, tergites.

Figure 10. Megaselia serrata female, details of abdomen, tergites 7–10.

Figure 11. Megaselia serrata female, details of abdomen, terminal segments from above.

Figure 12. Megaselia serrata female, details of abdomen, sternite 7.

Figure 13. Megaselia serrata female, details of abdomen, lobes at rear of sternum 8.

Figure 14. Megaselia serrata female, details of abdomen, furca.

Figure 15. Megaselia serrata female, details of abdomen, furca from a second specimen.

Figure 16. Megaselia serrata female, details of abdomen, furca from a third specimen.

Figure 17. Megaselia speiseri female, proboscis and palps.