Pleuroseta dorrigonis ( Richards, 1973 ) Kuwahara & Marshall, 2022

Kuwahara, Gregory K. & Marshall, Stephen A., 2022, A revision of the Australian species of Howickia Richards (Diptera: Sphaeroceridae: Limosininae), Zootaxa 5192 (1), pp. 1-152 : 10

Pleuroseta dorrigonis ( Richards, 1973) NEW COMBINATION

Leptocera (Biroina) dorrigonis Richards, 1973: 333 .

Biroina dorrigonis (Richards) , Marshall, 1989: 602; Roháček et al., 2001: 125.

Comments. Richards (1973) originally described this species as a species of Biroina (= Howickia ). However, examination of many specimens of “ Biroina dorrigonis ” ( Richards, 1973) and photos of the holotype showed that it is a species of Pleuroseta , with three pairs of dorsocentral bristles (the anterior-most pair presutural), a sinuate R 4+5, non-telescopic female terminalia, extremely large male genitalia, maculated legs, a distinct patch of setae on the anepisternum, and the male hypandrium lacking the ventral and posterodorsal apodemes that define Howickia . In Howickia , all dorsocentral bristles are postsutural, R 4+5 is straight or slightly curved, the female terminalia are elongate and telescoping, the male genitalia are not so enlarged, at least the tibiae are not maculated, and the anepisternum is bare.

All of these characters are shared with the type species of Pleuroseta , P. wentworthi Richards, 1973 . In his descriptions of “ B. dorrigonis ”, Richards (1973) does not mention how it differs from Pleuroseta , nor did he mention the presence of a lateral patch of setae on the anepisternum. However, the type specimen is externally very similar to the type of P. wentworthi , clearly with the diagnostic patch of setae on the anepisternum and differing only in its darker overall body colouration, distinctly banded legs, and smaller male genitalia. Therefore, “ Biroina ” dorrigonis is here treated as a species of Pleuroseta .

Phylogeny

Character state matrix

The plesiomorphic state is indicated by (0) and the apomorphic state(s) by (1–2). Multistate characters are treated as unordered. Polarity was established using Paralimosina + Eximilimosina as the outgroup. Characters marked with an asterisk are probable homoplasies associated with wing loss, and were excluded from the second analysis. Character numbers found in Figs. 2.1–2.3 correspond to the 33 characters listed below.

Head

1. Colour: (0) brown to black; (1) yellow to reddish-orange

2. Frons: (0) without stripes; (1) with microtomentose stripes

3. Interfrontal bristles: (0) 3; (1) 4–5; (2) 1–2

4. Orbital bristles: (0) 2; (1) 1; (2) 0

5. *Ocelli: (0) present; (1) absent or significantly reduced

Thorax

6. Colour: (0) brown to black; (1) yellow to reddish-orange

7. Dorsocentral bristles: (0) 2 pairs; (1) 1 pair

8. Acrostichal setulae: (0) 8 rows; (1) 10–12 rows; (2) 4–6 rows

9. *Scutellum: (0) normal, length 0.6–0.7x width; (1) broad, length 0.3–0.5x width

Legs

10. *Mid tibia: (0) distal half with 3 dorsal bristles; (1) distal half with 2 dorsal bristles

11. Male mid tibia, apicoventral comb: (0) absent; (1) present

12. Male mid tibia, stout apicoventral bristle: (0) present; (1) absent

Figures

FIGURES 2.1. Phylogeny of Australian species of Howickia Richards based on the morphological character states in Table 1 and the associated character list, including all characters associated with wing loss. The cladogram was rooted by Paralimosina Papp + Eximilimosina Papp as the outgroup. Solid circles indicate unique synapomorphies, empty circles indicate homoplasies, and crossed circles indicate reversals. Numbers above circles indicate the character number, numbers below the circles indicate multistate character states (unordered). Species names highlighted in blue indicate apterous species and names highlighted in green indicate brachypterous species. Tree branches highlighted in red indicate tentative species placements due to weak morphological support.