Sindosium, Johnson, 2007

Maté Nankervis, Jason F., 2020, Description of two new species of Sindosium Johnson, 2007 from Australia (Coleoptera, Ptiliidae), Zootaxa 4895 (4), pp. 528-540 : 538-539

Revised key to the known species of Sindosium

The following key has been generated from the original descriptions in Johnson (2007) and Darby (2019a, 2019b) as well as from the available material pertaining to the new species described herein.

1 Mesoventral collar with a pair of deep pubescent foveae posteriorly............................................. 2

- Mesoventral collar without deep foveae or at most just impressed............................................... 5

2 Pronotum evenly convex, without any impressions or foveae on the disc, clearly punctate throughout, though puncturation may be sparse on disc or absent in a medial strip................................................................ 3

- Pronotum impunctate, with a conspicuous medial fovea. Larger species, body length: 0.86–1.12mm ...................................................................................................... foveatum Johnson, 2007

3 Foveolate pronotum with shorter pubescence. Mesocoxae more widely separated, equal to the width of the mesotibia. Smaller species, body length: 0.94mm ............................................................ collinsi Darby, 2019

- Pronotum not foveolate, pubescence long and dense throughout. Mesocoxae close, separation decidedly less than the width of the mesotibia. Larger species............................................................................ 4

4 Head narrower; pronotum with hind corners curved outwards, obviously projected; metaepisternum posteriorly divergent ( Fig. 1B ); metacoxal bifid projection narrower, sinuate ( Fig. 2B ); row of setae on 5th ventrite much denser than rest. Aedaegus ( Fig. 2E ) & spermatheca ( Fig. 2D ). Length 0.98-1.12mm ......................................... queenslandicum n. sp.

- Head wider; pronotum with hind corners straight or bent inwards, never projected; metaepisternum posteriorly narrower, partly subparallel ( Fig. 3B ); metacoxal bifid projection wider, falcate ( Fig. 4B ); abdominal segments with setation similar on all rows. Aedaegus ( Fig. 4E ) and spermatheca ( Fig. 4D ). Length 1.04-1.27mm ................................ lamingtoni n. sp.

5 Pronotum sparsely and regularly punctured, laterally evenly explanate. Elytra opaque, with iridiscent sheen. Smaller species, 0.82mm ......................................................................... opacipenne Johnson, 2007

- Pronotum sparsely punctured except for median bare strip, with its sides strongly and unevenly explanate, with posterior lateral areas much widened, its boders serrate. Elytra neither opaque nor iridescent. Larger species, 1.07mm ....................................................................................................... bacchusi Darby, 2019

Figures

FIGURE 1. A. Dorsal habitus of holotype of Sindosium queenslandicum sp. nov.; B Metaventral metepisternum showing the divergent posterior suture (Mt Macartney paratype). Scale bar: 0.1mm.

FIGURE 2. A. Ventral view of transparent preparation of Sindosium queenslandicum sp. nov.; B. Posterior end of metaventrite showing bifid projection; C. Abdomen showing wing folding patches in segment 2–6: D. Spermatheca; E. Aedaegus; F. Extended wing showing the structure of the peduncle and the complex venation of the wing relative to other ptiliids. All material from the Mt Macartney type locality.

FIGURE 3. A. Dorsal habitus of holotype of Sindosium lamingtoni sp. nov.; B. Metaventral metepisternum showing the divergent posterior suture (paratype from Lamington N.P.). Scale bar: 0.1mm.

FIGURE 4. A. Ventral view of transparent preparation of Sindosium lamingtoni sp. nov.; B. Posterior end of metaventrite showing bifid projection; C. Abdomen; D. Spermatheca; E. Aedaegus. All material from the Lamington National Park type locality.