Cheiloxena monga, Reid & Beatson, 2018

Reid, C. A. M. & Beatson, M., 2018, Revision of the Australian leaf beetle genus Cheiloxena Baly, 1860 (Coleoptera: Chrysomelidae: Spilopyrinae), Zootaxa 4497 (4), pp. 501-534 : 526-527

Cheiloxena monga sp. nov.

( Figs 9 , 18 , 27 , 34 , 48 , 58 , 77 )

Cheiloxena frenchae male, sensu Reid 1992, nec Blackburn1893.

Mateiral examined. Type. Holotype: Ƌ*/ 5k SSW Monga NSW Euc. rubida 12.xi.1985 C. Reid/ (ANIC).

Diagnosis. Cheiloxena monga is distinguished by: upper and lower surfaces scaled; anterior margin of clypeus truncate; pronotum with almost parallel paired ridges; hypomeral lobe rugose, without scales; apical half of elytra conspicuously tuberculate, with largest tubercles arranged in a curve.

Description (female unknown). Length 11 mm; body moderately convex in profile, length about 3x height; colour black, but elytra mostly dark brown with black tubercles, and maxillary and labial palpi reddish-brown; almost entirely clothed with adpressed creamy-white scale-like setae (length 3– 5x width), not distinctly variegated in colour, setae not thinner on depressed areas of pronotum and elytra, thinner on anterior of clypeus, apices of mandibles, prosternal and mesoventral processes, legs, apex of abdominal ventrite V, and antennomeres 1–7, scalelike setae absent from antennomeres 8–11 (minute simple setae only); scale-like setae distributed as follows: almost evenly on head but clypeal margins anteriorly glabrous; almost evenly on pronotum but slightly sparser on depressed areas and absent from apices of ridges; scutellum clothed with thin setae; elytra with irregular mosaic of dense patches and more sparsely setose areas, setae of larger tubercles not differentiated except slightly more elongate; ventral surfaces with dense white adpressed setae except thin and sparse on apical half of ventrite V, setae of appendages thin but dense (except antennomeres 8–11); surface sculpture: head including clypeal margins, pronotum and metaventrite densely punctured and microreticulate, dull, elytra and rest of thoracic venter, including pronotal hypomera, densely microsculptured and dull; apices of tubercles and ridges, and abdominal ventrites shiny and not or shallowly microsculptured.

Head ( Figs 9 , 18 , 27 ): slightly narrower than pronotum; densely and slightly confluently punctured, punctures small but larger than ommatidia, intervals dull and microsculptured, including narrow impunctate frontoclypeal sutures, apical margin clypeus, and margin of antennal cavities; convex between eyes, shallowly concave between antennae; eyes laterally prominent, separated by about 3 eye widths; gena at shortest point about 0.3x eye length; genal lobe 2x shortest length of gena; antennae 3x socket diameters apart; antennae about 0.75x body length; antennomeres 1–6 dull with shining apices, apical half of 7, and whole of 8–11 matt; antennomeres 1 and 3–11 elongate, 2 slightly transverse and about 0.5x length of 1, 0.25x length of 3, relative lengths of antennomeres, with 3 longest and 7 next, and middle segments unequal in length: 2, <1, <8, <4=9=10, <6, <5, <11, <7, <3; clypeus with 2 pairs of long subapical setae; clypeal anterior margin truncate; apical maxillary palpomere broadly ovoid, with truncate apex.

Thorax ( Figs 9 , 18 , 27 , 34 ): sides bulging slightly at middle, no clear distinction between dorsal and ventral (hypomeral) areas of pronotum; pronotal punctures dense, diameters 1.5– 2x larger than on head; interspaces dull, densely microsculptured; pronotum slightly wider than long (measured at midline), length 0.95x width, greatest width at middle, sides weakly sinuate; anterior angles prominent but apices blunt, 90°; anterior margin produced, concave at middle; sides without tubercles; basal margin truncate; pronotal disc with two prominent subparallel keels from middle to anterior margin, almost symmetrically convex in lateral view, sharper in anterior half; remainder of disc unevenly surfaced, concave apicolaterally and either side of small postmedian swelling; hypomeron and prosternum densely punctured and pubescent, as pronotum, except hypomeral lobe rugose and glabrous; scutellum closely punctured and setose, scales more elongate than on pronotum; elytra irregularly scaled, forming network of pale flecks; elytron conspicuously tuberculate, with variably sized shiny-tipped tubercles arranged in approximately 4 clusters close to suture, from base to apex, as follows: first (basal) with 1 large blunt tubercle at apex of ridge from base of elytra; second (median) with 1 smaller conical or elongate tubercle; third (subapical) with 3 conical tubercles arranged in an equilateral triangle, largest lateral and smallest basal; fourth (apical) with 3 conspicuous but smaller well-separated tubercles arranged in an equilateral triangle; small tubercles scattered at base and sides of elytron; elytral disc shallowly arcuately depressed in basal half, posterior to humerus, and concave at sides of middle; elytral punctures large, similar diameter to largest on pronotum, but much deeper, and slightly sparser, separated by 1–1.5x diameters; interspaces dull, densely microsculptured; discal elytral punctures with two small shining tubercles laterally on rim; elytral apex narrowly truncate; epipleuron finely and shallowly punctured, with scale-like pubescence; mesoventrite punctured as prosternum; metepisternum and metaventrite dull and microsculptured, densely punctured and scaled, except midline impunctate and shining; metatibiae with shallow irregular lateral longitudinal grooves, thin and elongated; bases of tarsomeres 1–3 depressed and not expanded.

Abdomen ( Figs 48 , 58 ): ventrites I–V shinier than thoracic ventrites, strongly but less densely punctured and more shallowly microreticulate; ventrite pubescence recumbent, scale-like, but much narrower on ventrite V, only erect setae present on apical half of ventrite V; apex of ventrite V feebly convex; apex of penis contracted to blunt mucronate tip in dorsal view, apex thick and short in lateral view, strongly curved; tegminal keel shallowly sinuate in lateral view, with acute simple proximal tip.

Etymology. Named from the type locality, as a noun in apposition.

Notes. Cheiloxena monga is only known from the holotype, collected at the margin of cool temperate rainforest and tall eucalypt forest in what is now Monga National Park. It was beaten off a sapling of Eucalyptus rubida , now a synonym of E. dalrympleana (Myrtaceae) , with no evidence of feeding.

This specimen was previously incorporated in a description of C. frenchae , when the only other known specimen of that species was the holotype ( Reid 1992). Based on the small amount of additional material of this complex ( C. aitori , C. frenchae and C. monga ) made available since 1992 we now believe that the Monga specimen represents a valid species.

Figures

FIGURE 77. Eastern Australia showing distribution of Cheiloxena species.

FIGURES 7–10. Habitus of Cheiloxena species: 7, C. insignis Baly (Launching Place, Victoria); 8, C. insignis (Lake Mountain, Victoria); 9, C. monga Reid & Beatson (holotype); 10, C. tuberosa Reid; Not to scale.

FIGURES 13–21. Lateral of Cheiloxena species: 13, C. aitori Reid & Beatson, male (holotype); 14, C. blackburni Reid; 15, C. conani Reid & Beatson; 16, C. frenchae Blackburn, (holotype); 17, C. insignis Blackburn; 18, C. monga Reid & Beatson (holotype); 19, C. tuberosa Reid; 20, C. westwoodii Baly (northern form, Dorrigo); 21, C. westwoodii Baly (southern form, Victoria). Not to scale.

FIGURES 22–30. Anterior view, Cheiloxena species: 22, C. aitori Reid & Beatson, male (holotype); 23, C. blackburni Reid; 24, C. conani Reid & Beatson; 25, C. frenchae Blackburn; 26, C. insignis Baly; 27, C. monga Reid & Beatson; 28, C. tuberosa Reid; 29, C. westwoodii Baly (northern form, Dorrigo); 30, C. westwoodii Baly (southern form, Victoria).

FIGURES 31–34. Dorsal of pronotum, Cheiloxena species: 31, C. aitori Reid & Beatson, male (holotype); 32, C. blackburni Reid; 33, C. frenchae Blackburn; 34, C. monga Reid & Beatson.

FIGURES 43–51. Cheiloxena species, male genitalia lateral and dorsal: 43, C. aitori Reid & Beatson; 44, C. blackburni Reid; 45, C. conani Reid & Beatson; 46, C. frenchae Blackburn; 47, C. insignis Blackburn; 48, C. monga Reid & Beatson; 49, C. tuberosa Reid; 50, C. westwoodii Baly (northern form, Dorrigo); 51, C. westwoodii (southern form, Victoria). All images to scale, scale bar = 2mm.

FIGURES 52–61. Cheiloxena species, apex of penis: 52, C. aitori Reid & Beatson; 53, C. blackburni Reid; 54, C. conani Reid & Beatson; 55, C. frenchae Blackburn; 56, C. insignis Blackburn (Launching Place, Victoria); 57, C. insignis Blackburn (Lake Mountain, Victoria); 58, C. monga Reid & Beatson; 59, C. tuberosa Reid; 60, C. westwoodii Baly (northern form, Dorrigo); 61, C. westwoodii (southern form, Victoria). All images to same scale.