Australara glaisteri, Barr & Shepard, 2021

Barr, Cheryl B. & Shepard, William D., 2021, A review of the Larainae of Australia with description of seven new species and the new genus Australara (Coleoptera, Byrrhoidea, Elmidae), ZooKeys 1073, pp. 55-117 : 55

Australara glaisteri sp. nov.

Figs 1 , 13 , 14

Type locality.

Mulgrave River south of Gordonvale; 17.1028°S, 145.7875°E; north Queensland, Australia.

Type material.

Holotype, male. "AUSTRALIA: Queensland / 1 km S Gordonvale / 18 I 2001 94 ft / Mulgrave River (WDS-A-1371 on reverse) // William D. / Shepard, leg. // HOLOTYPE / Australara / Australara glaisteri / Barr & Shepard" [red label, handwritten]. Dry pinned. Deposited in the Australian National Insect Collection, Canberra; ANIC Database Number 25-077640. Paratypes (2). Same data as for holotype // PARATYPE / Australara / Australara glaisteri / Barr & Shepard [yellow label, printed] (2 ♂♂ EMEC).

Differential diagnosis.

Australara glaisteri (Figs 13 , 14 ) may be separated from other laraine species by the characters given in the generic diagnosis: Hydora laticeps (Figs 15 - 22 ) shares some similarities, but differs by having strong sublateral pronotal carinae, whereas A. glaisteri has none. Unlike A. glaisteri , Stetholus species (Figs 34 - 42 ) have shorter, distinctly clavate antennae, and the prosternum is very short anterior to the procoxae. The male genitalia of A. glaisteri (Fig. 14 ) are unusual, with the penis curved strongly in a dorsal direction.

Description

(n = 3). Male. Body: Size 3.7-4.0 mm long, 1.4-1.5 mm wide; elongate, 2.5-3 × longer than wide. Dorsal color very dark brown; venter medium brown; head black; first 2 antennomeres, basal palpomeres, coxae, trochanters, femora yellow-brown; tibiae, tarsi, apical antennomeres, apical palpomeres brown. All surfaces with short to moderately long yellow setae, setae more dense ventrally than dorsally; dorsal cuticle shiny. Head: Densely and finely punctate, punctures 1 diameter apart or less; moderately setose, setae moderately long. Frons moderately protuberant between eyes, with adjacent lateral excavations and a pair of fossae above antennal bases; frontoclypeal suture straight. Antenna with eleven antennomeres, very long, thin, forming a loose, slightly asymmetrical club; antennomere 1 longest, ~ 3 × longer than wide, slightly curved; antennomere 2 ovoid; antennomeres 3-10 subserrate, with antennomeres 5-10 subequal in size; antennomere 11 broadly ovoid. Eye finely faceted, almost circular at base, moderately protuberant; dorsal margin with fringe of long, curved setae. Clypeus transverse, very short, ~ 7 × wider than long; anterior margin weakly emarginate; disc granulate; lateral margins with long setae. White membranous area visible between clypeus and labrum. Labrum rectangular,> 2 × wider than long, longer and wider than clypeus; anterior margin straight; disc granulate, very setose; lateral margins broadly rounded with long, yellow setae. Mandible with three teeth, apical pointed, 2nd triangular, 3rd smallest and triangular; lateral margins with several long setae. Maxillary palpus long, robust, setose, with four palpomeres; palpomere 1 short, annular; palpomere 2 twice as long as wide; palpomere 3 shorter and wider than 2, wider apically; palpomere 4 wide, ovoid, apex angled obliquely, ventral surface with a narrowly oval, white sensory area. Galea and lacinia long, finger-like, both with long setae. Labial palpus long, robust, yellow, with three setose palpomeres; palpomere 1 short and narrow, annular; palpomere 2 twice as wide as 1; palpomere 3 conical, apex with white, digitiform, sensory area. Pronotum: Shape nearly quadrate, slightly wider than long, widest at base; 0.9-1.0 mm long, 1.1-1.2 mm wide; disc densely punctate, punctures spaced ~ 1 diameter apart. Anterior margin thickened, straight; anterior angles obsolete; lateral margins weakly sinuate, marginate; posterior angles depressed, lateral margins raised, variably produced with tips generally blunt; posterior margin weakly trisinuate. Disc moderately convex; two faint, anterior transverse impressions laterad of the midline at anterior 1/4; two faint to distinct shallow, elongate, sublateral impressions ~ 1/3 length of pronotum; two prescutellar foveae joined by a shallow, transverse impression. Scutellar shield: As long as wide, apex rounded; flat; densely setose. Elytron: 2.8-3.0 mm long, 0.7-0.8 mm wide. Elytra conjointly 2 × as long as wide; generally parallel-sided; laterally compressed at basal 1/2; lateral margins strongly marginate. Humerus inflated, elytral base slightly depressed; disc moderately convex at anterior 1/4 median to humerus; moderately depressed at anterior 1/4-1/3 posterior to humerus; then weakly convex to apex. Disc with ten small, shallowly punctate, weakly impressed striae, intervals nearly flat; short, faint, accessory basal stria with close to ten punctures between striae 1 and 2; striae 2 and 3 end before apex; disc punctures of variable size, separated by <1 diameter, more distinct basally, smaller and closer apically. Metathoracic wings: Macropterous. Prosternum: Moderately short anterior to procoxae, disc very setose with widely spaced punctures; prosternal process spinose, long, 5 × longer than wide, carinate with carina extending anterior of procoxae, apex narrowly rounded. Mesoventrite: Very setose; surface elevated at midline anterior to mesocoxae to form a narrow projection from the anterior margin with two carinae enclosing a slit-like mesoventral cavity; area anterior to mesocoxae shallowly excavated for procoxae; disc depressed between mesocoxae; posterior margin emarginated medially. Metaventrite: Broadly rectangular; very setose, moderately granulate; anterior margin moderately produced between mesocoxae; disc laterally convex, medially with a shallow, wide concave area surrounding discrimen; discrimen extending from anterior 1/4 to posterior margin, deeply incised; metakatepisternal suture distinct. Legs: Long, slender, of similar lengths; each leg with femur and tibia subequal in length; tarsus with tarsomere 5 distinctly shorter than tarsomeres 1-4 combined. Coxae and femora yellow-brown; tibiae brown, each with a pair of stout spines at ventral apex; meso- and metatibiae with posterior surfaces shallowly sulcate, yellow-brown, glabrous, shiny; tarsi brown; claws simple, long, sharply acute. Abdomen: Strongly convex, lateral margins concealed by elytra; densely setose and moderately granulate; with five ventrites, ventrites 1-4 of subequal length, ventrite 5 slightly longer; ventrite 1 with a long, narrow median, triangular intercoxal projection; ventrite 5 posterior margin with a median emargination. Aedeagus: Approximately 3.5 × longer than wide, generally parallel-sided at basal 3/4; phallobase longer than parameres, penis slightly longer than parameres (Fig. 14 ). Parameres, in dorsal view (Fig. 14A ), widest at base; lateral margins nearly parallel at basal 1/2, then weakly divergent at apical 1/2; medial margin weakly arcuate; apex produced, acute. Penis, in dorsal view, widest basally, lateral margins evenly convergent to rounded apex; no visible corona; basal apophyses short, <1/4 as long as phallobase, straight, broad, blunt at tips. In lateral view (14B), penis strongly curved dorsally above parameres at ~ 30° angle, apex rounded; paramere triangular, apex produced, acute. Fibula absent.

Variation.

The three specimens varied in size from 3.7-4.0 mm long and 1.4-1.5 mm wide. Because the small series of A. glaisteri is all male, it was not possible to make a comparison with the female of the species. Among the three, the two shallow, elongate, sublateral pronotal impressions vary from faint to distinct. Also, the posterior pronotal angles differ in the amount to which they are produced, the shape of the angle (nearly 90° to acute), and whether the tip is truncate, blunt, or sharp. It is possible that the median emargination on the posterior margin of abdominal ventrite 5 is a male characteristic not present in females.

Etymology.

The specific epithet glaisteri, a noun in the genitive case, is given in honor of Alena Glaister of Monash University, VIC, who devised a successful method of rearing Australian larval elmids to adults, thereby enabling their association. She published an extensively illustrated identification guide to the larval Elmidae of Australia with keys and descriptive notes on taxonomy, distribution, and habitat. Few elmid researchers have attempted such work, and none have produced larval keys covering so many taxa.

Distribution.

Known only from the type locality in north Queensland, Australia (Fig. 1 ).

Habitat.

At the collection site during low water stage, the Mulgrave River was mostly shallow, with warm, clear water and a fairly swift current over a substrate of sand and gravel. Decomposing wood and log jams, where Australara and other laraines were found, were abundant along the banks of the wide channel. The locality is at ~ 30 m elevation and bordered by a town and sugarcane fields not far from the ocean. Local residents told us that in past years saltwater crocodiles frequented the river until the sugarcane farmers shot them out.

Associated byrrhoid taxa.

Elmidae : Larainae : Ovolara leai , O. monteithi sp. nov., Stetholus longipennis sp. nov.; Elminae : Austrolimnius spp., Graphelmis pallidipes (Carter), Kingolus spp., Notriolus spp., Simsonia spp.

Figures

Figure 15. Hydora laticeps, lectotype male A specimen labels B dorsal habitus C ventral head and prosternum D lateral head and pronotum (photographs courtesy of the Australian Museum, Natalie Tees).

Figure 22. Hydora laticeps, non-type female from Cann River, VIC A dorsal habitus B ventral habitus C lateral habitus (photographs courtesy of the Queensland Museum, Geoff Thompson).

Figures 1 - 12. Geographical distribution of species records 1 Australara glaisteri gen. nov., sp. nov. 2 Hydora laticeps 3 Ovolara australis 4 Ovolara lawrencei sp. nov. 5 Ovolara leai 6 Ovolara monteithi sp. nov. 7 Potamophilinus papuanus 8 Stetholus carinatus sp. nov. 9 Stetholus elongatus 10 Stetholus longipennis sp. nov. 11 Stetholus metatibialis sp. nov. 12 Stetholus woronora sp. nov.

Figures 13, 14. Australara glaisteri gen. nov., sp. nov., male 13 habitus A dorsal B ventral (photographs courtesy of the Australian National Insect Collection, CSIRO, Zhenhua Liu) 14 male genitalia A dorsal view B lateral view C ventral view.

Figures 34, 35. Stetholus carinatus sp. nov., holotype male 34 habitus, 3.7 mm long A dorsal B ventral 35 male genitalia A dorsal view B lateral view C ventral view.

Figures 41, 42. Stetholus woronora sp. nov., holotype male 41 habitus, 5.2 mm long A dorsal B ventral 42 male genitalia A dorsal view B lateral view C ventral view.