Allothnonius brooksi Britton, 1978

Allsopp, Peter G. & Smith, Andrew B. T., 2022, Australian Melolonthini (Coleoptera: Scarabaeidae: Melolonthinae): a third species of Allothnonius Britton, 1978, and notes on the other known species, Zootaxa 5099 (4), pp. 475-484 : 480-482

Allothnonius brooksi Britton, 1978

( Figs. 11–18 )

Allothnonius brooksi Britton, 1978: 39 , Figs. 13 , 117–119, 276A; Weir et al. 2019, Fig. 31.156, Plate 60B.

Type series. Holotype (by original designation) ♂: AUSTRALIA: QUEENSLAND: Emmett Creek, Cromarty [19.47°S, 147.05°E], 6.xii.[19]65, J.G. Brooks & E.P. Brooks [ ANIC, examined].

Paratypes (examined). AUSTRALIA: QUEENSLAND: 20♂, same data as holotype [ ANIC] ; 4♂, Townsville [19.26°S, 146.82°E], Dodd [ SAM] ; 4♂ on one card, Emmett Creek, Cromarty , about 20 miles S Townsville, 6.xii.1963, J.G. Brooks & E.P. Brooks [ ANIC] ; 2♂, Cromarty, Townsville , 6.i.1964, J.G. Brooks [ ANIC] ; 2♂, Brandon [19.55°S, 147.35°E], 13.viii.1968, I.T. Freshwater [ ANIC, QM registration number T250928] .

Other specimens examined. AUSTRALIA: QUEENSLAND. 1♂, Emmett Creek , Cromarty, 6.xii.1965 J. A. G. Brooks [ QDAF registration number 1-004151]; 1♂, Cromarty, 12 km south, J & E B[rooks] [ ANIC]; 1♀, Brandon [19.55°S, 147.35°E], 13.viii.1968 , I. T. Freshwater [ QM]; 18♂ Airville [19.65°S, 147.35°E], 21.i.[19]70 , A. Johnson E. Adams [ ANIC] .

Redescription Male ( Figs 11–14 ). Body 11–14 mm long; head, pronotum, scutellum, and ventral thorax black; elytra and abdominal ventrites dark red-brown; antennae pale yellow-brown, scape sometimes light brown; palpi and tarsi reddish brown; coxae, femora, and tibiae very dark brown to black. Labrum rounded laterally with slight median indentation, not protruding beyond anterior margin of upper clypeus, with a few scattered, short setae. Terminal palpomere of maxillary palp slender, about as long as palpomeres 1–2 together, with dull area on upper surface. Anterior face of clypeus 4x as wide as long, with setiferous punctures along anterior margin, posterior surface smooth; outline of upper surface broadly rounded, without emargination but reflexed on anterior, surface very coarsely punctured, long, yellow-brown setae intermixed with a few, flattened, adpressed, white setae across the posterior margin and scattered on anterior half. Frons coarsely and densely punctured, covered with dense, long yellow-brown setae intermixed with a few short, adpressed, white setae; ocular canthi with dense fringe of long, stout, yellow-brown setae. Antennal club 6-lamellate, all lamellae about the same length; antennomere 4 slightly wedge-shaped anteriorly. Pronotal width across base 2x mid length, sides obtusely angled in middle, anterior angles widely obtuse, posterior angles obtuse and slightly rounded, anterior and poster margins narrowly raised and defined by grooves continuous from side to side except in middle of posterior margin; surface coarsely punctured, covered with long, erect, yellow-brown setae intermixed with short, flattened, white setae varying in size from contained within their punctures to about 2x puncture diameter. Scutellum with a few scattered setae similar to both pronotal types. Elytra with only sutural stria impressed, surface fairly uniformly punctured, punctures smaller than those on pronotum and each containing a small, pale seta; lateral margins with a fringe of very long, stout, light-brown setae. Propygidium and pygidium uniformly clothed with recumbent, parallel-sided, flattened, white setae. Ventral thorax with dense, long, pale-yellow setae. Legs with scattered, pale-yellow setae and a few flattened, white setae. Abdominal ventrites with long, pale-yellow setae intermixed with denser, flattened, white setae. Aedeagus ( Figs. 12–14 ) with lateral edges almost parallel then rounded at apices.

Female ( Figs. 15–17 ). Body 13.8 mm long; head, pronotum, scutellum, and ventral thorax dark brown; elytra and abdominal ventrites red-brown; antennae pale yellow-brown, scape light brown; palpi and legs reddish brown, coxae brown. Labrum rounded anteriorly, not protruding beyond anterior margin of upper clypeus, with a few scattered, short setae. Terminal palpomere of maxillary palp slender, about as long as palpomere 1, with dull area on upper surface. Anterior face of clypeus 4x as wide as long, with setiferous punctures across middle, anterior surface smooth, posterior surface smooth with occasional punctures; outline of upper surface broadly rounded, without emargination but slightly reflexed on anterior, surface very coarsely punctured, with long, yellow-brown setae. Frons coarsely and densely punctured, covered with dense, long yellow-brown setae intermixed with a few short, adpressed, white setae; ocular canthi with dense fringe of long, stout, yellow-brown setae. Antennae of 10 antennomeres, club 6-lamellate but club rounded with lamella of antennomere 5 about 0.5x length of antennomere 9 (the longest antennomere of the club). Pronotal width across base 1.9x mid length, sides rounded, anterior angles widely obtuse, posterior angles slightly obtuse and slightly rounded, anterior and poster margins narrowly raised and defined by grooves continuous from side to side except in middle of posterior margin; surface coarsely punctured, covered with long, erect, yellow-brown setae intermixed with short, flattened, white setae varying in size from contained within their punctures to about 2x puncture diameter. Scutellum with a few scattered setae similar to both pronotal types. Elytra with only sutural stria impressed, surface fairly uniformly punctured, punctures smaller than those on pronotum and each containing a small, pale seta; lateral margins with a fringe of very long, stout, lightbrown setae. Propygidium and pygidium uniformly clothed with recumbent, parallel-sided, flattened, white setae. Ventral thorax with dense, long, pale-yellow setae. Legs with scattered, pale-yellow setae and a few flattened, white setae. Abdominal ventrites with long, pale-yellow setae intermixed with denser, flattened, white setae.

Distribution. Known from the coastal area between Townsville and Ayr in northeastern Queensland ( Fig. 18 ). All localities have a Köppen-Geiger climate classification of Aw (savannah).

Natural history. Adults of both sexes have been collected in August and December–January.

Female antennae ( Fig. 17 ) are consistent ( Allsopp 1990) with other Australian old-Gondwanan Melolonthini ( Allsopp 1995) where both genders do not feed as adults, and the females fly little (if at all) and attract males with pheromones ( Allsopp 1993). This contrasts with more recent Oriental arrivals, such as Lepidiota spp. , where male and female antennal clubs are similar, and mating appears to take place at feeding sites.

Figures

FIGURE 18. Known collection localities of Allothnonius spp. in northern Australia.

FIGURES 7–14. Allothnonius spp., males. 7–10. Allothnonius barretti Britton, 1978. 7, dorsal view; 8, aedeagus, lateral view; 9, aedeagus, dorsal view; 10, aedeagus, ventral view. 11–14. Allothnonius brooksi Britton, 1978. 11, dorsal view; 12, aedeagus, lateral view; 13, aedeagus, dorsal view; 14, aedeagus, ventral view. Figs. 8–10, 12–14 reproduced from Britton (1978) (© CSIRO).

FIGURES 15–17. Allothnonius brooksi Britton, 1978, female. 15, dorsal view; 16, ventral view; 17, dorso-lateral view.