Scirtes lynnae, Watts & Cooper & Saint, 2017

Watts, Chris H. S., Cooper, Steven J. B. & Saint, Kathleen M., 2017, Review of Australian Scirtes Illiger, Ora Clark and Exochomoscirtes Pic (Coleoptera: Scirtidae) including descriptions of new species, new groups and a multi-gene molecular phylogeny of Australian and non-Australian species, Zootaxa 4347 (3), pp. 511-532 : 525-526

Scirtes lynnae sp. nov.

( Figs 20 , 26 )

Type material. Holotype ♂, “SA 1 Km S Nangwarry 37 33 140 46 20/10 /14 CHS Watts/ Bred from larva.”, SAMA. Paratype ♂ as for holotype, SAMA.

Description (number examined, 2).

Habitus. Length 2.2–2.4 mm, oval.

Head. Dark testaceous; antenna testaceous, basal antennomeres lighter. Eyes rather small, width between eyes about 3.8× dorsal width of eye. Setae moderately long, pale. Frons with sides weakly diverging, front edge straight, edges weakly beaded. Antennomere 1 of antenna narrowly barrel-shaped; antennomere 2 about three-quarters as long and not much narrower, barrel-shaped; antennomere 3 about three-quarters length of antennomere 2, slightly narrower, wider towards apex; antennomere 4 about 1.5× length of antennomere 3; antennomeres 5–10 subequal, narrow, cylindrical, a little shorter than antennomere 4; antennomere 11 elongate/oval, 1.4× length of and flatter than antennomere 10.

Pronotum. Dark testaceous; broad, 2.7× as wide as long. Punctures moderately large, about a puncture width apart, each puncture with a moderately long golden seta. Hind angles weakly obtuse, front edge sinuate, margins weakly beaded.

Scutellar shield. Testaceous. Equilateral triangle, lateral sides weakly convex.

Elytra. Light testaceous, base and humeral angles darker. Sides weakly flanged in basal third. Strongly and evenly punctate, somewhat larger than on pronotum, most punctures less than a puncture width apart or less, each puncture with a moderately long pale seta. Epipleuron relatively wide in front quarter, becoming narrower over rest of elytron, front portion flat.

Ventral surface. Testaceous. Pronotal process very narrow at apex. Mesoventral notch “U”-shaped. Mesoventral process long, narrow, reaching to metaventrite. Metacoxal plate almost square, anterior-lateral corner extending a short way along metaventrite; hind edge straight; sides beaded, posterolateral angles rounded. Metatrochanter small, relatively squat, about 1.2× as long as wide. Metafemur greatly swollen, widest a little before middle, weakly notched on rear margin near apex. Dorsal metatibial spine, about half length of ventral spine, ventral spine about two-thirds length of segment 1 of metatarsus; segment 1 of metatarsus a little longer than other segments combined. Ventrites with very small, shallow punctures each with a short seta, reticulation moderate, fine, more pronounced towards rear.

Male. Basal piece short, round; trigonium long, broad at base, evenly narrowing to rounded tip, about 2× length of pala; ventral edge smooth; two parameroids, right hand one about half length of trigonium, thin, without apical hook, left hand parameroid very small, oval. Tegmen two-thirds as long as penis, lobes thin, finger-like, well separated ( Fig. 20 ). Tergite 8 broad short, apodemes straight well sclerotized. Tergite 9 smaller and weaker. Sternite 8 not known.

Female. Not known.

Etymology. Named after Lynn Strefford of the South Australian Museum who has very competently done much of the unsung administrative work in support of our studies over many years.

Notes. In small size and dark colour it greatly resembles Scirtes pinjarraensis but differs from that species in the straight right parameroid, and the absence of spines at the apex of the trigonium ( Fig. 22 ). Sequence data ( Fig. 1 ) place the species as sister species to S. orientalis . In the key to Australian Scirtes in Watts (2004) it will run to S. brisbanensis / S. pinjarraensis , but can be separated from S. brisbanensis by its small size, rounded rather than pointed apex of the trigonium and dark rather than mainly chestnut coloured dorsal surface and from S. pinjarraensis by the very different apex of the trigonium ( Figs 20, 22 ). The small black larvae were abundant in a drying pool in a reed/weed choked swamp.

Larvae. Scirtes lynnae runs to the S. helmsi / S. orientalis couplet in Watts (2014). Its small size separates it from S. helmsi and also S. serratus with which it is sympatric. It differs from S. orientalis in generally having fewer claw teeth (6–7 vs 7–9) and broader tergite 9. From Scirtes triangularis , which also runs to S. orientalis , it differs in its smaller size and single row of palisade setae on the clypeolabrum ( Fig. 26 ).

Figures

FIGURE 1. Phylogenetic tree of Australian Scirtes, Ora, Exochomoscirtes and some related Asian species, based on Bayesian inference (BI) analysis of concatenated sequence data of COI, EF 1 - a and TOP 1. A tree with identical topology was obtained using ML analyses of the same data set and a concatenated dataset comprising only COI and TOP 1. Numbers on branches give posterior probabilities (left) from BI analyses and bootstrap proportions (right) as a percentage of 500 pseudoreplicates from a ML analysis.

FIGURES 17 – 22. Tegmen and penis of: 17) Scirtes auratus; 18) S. serratus; 19) S. interstinctus; 20) S. lynnae; 21) S. albamaculatus. 22) Penis of S. pinjarraensis.

FIGURES 23 – 28. 23) Male terminalia of Scirtes zwicki: a) tergite 8, b) tergite 9, c) sternite 9, d) trigonium, e) tegmen. 24) Habitus photograph of Scirtes zwicki; 25) ditto, ♀ S. albamaculatus. 26) Clypeolabrum of last instar larva of S. lynnae; 27) ditto, S. serratus; 28) ditto, S. triangularis.