Macratria bimaculosa, Telnov, 2023

Telnov, Dmitry, 2023, Fourth contribution to the Macratriinae LeConte, 1862 of the Papuan Region and Wallacea (Coleoptera: Anthicidae) with descriptions of sixteen new species, Zootaxa 5361 (1), pp. 1-52 : 6-8

Macratria bimaculosa sp. nov.

urn:lsid:zoobank.org:act:7F39E6A5-DB46-4B77-903B-B87CEC513B1C

( Figs 8–12 )

Type material designated. Holotype ♂ NME: INDONESIA E, New Guinea, Papua Prov., Sarmi 76 km ESE, Biri River , 02°11’09’’S 139°20’57’’E, 27 m, 28.III.1998, river valley, from riverside vegetation [printed].

Paratype 1♂ DTC: same label as holotype.

Derivatio nominis. Toponymic. Named from Latin “bimaculosa ” (twin-spotted) to highlight the white bimaculate elytra of the new species.

Measurements, holotype male, total body length 3.6 mm; head length 0.7 mm, head width across compound eyes 0.65 mm, pronotal length 0.85 mm, maximum pronotal width 0.6 mm, elytral length 2.1 mm, combined maximum elytral width 0.9 mm. Male paratype 3.2 mm long.

Description. Male ( Fig. 8 ). Dorsum and venter uniformly black. Mouthparts, antennomeres 1–7, maxillary palpomeres 2–3 yellow. Remaining antennomeres, terminal maxillary palpomere and protibia yellowish brown. Tarsi brown. Scutellar shield castaneous on the holotype, black in the paratype. Head moderately glossy dorsally and ventrally, nearly circular. Frons narrow, about 0.6× as wide as dorsal eye length. Compound eye large, occupying whole lateral side of head beyond antennal insertion, strongly protruding from lateral outline of head. Interfacetal setae moderately long, moderately dense. Tempus not present, area posterior to eye rounded in a broad arc with head base. Frontoclypeal suture or impression not observed. Head dorsal punctures shallow, inconspicuous, median area of head widely unpunctured. Intervening spaces smooth, as wide as to 4× as wide as punctures. Head dorsal setae whitish, subdecumbent, moderately dense. Tactile setae sparse, yellowish, erect, longer than ordinary setae. Antenna slender and strongly filiform, extending towards base of elytra when directed posteriad. Basal antennomere elongate, about 1.2–1.3× as long as antennomere two. Antennomere three 1.2–1.3× as long as antennomere two, about as long as antennomere four. Antennomeres 3–8 long and slender, 9–10 widened. Terminal antennomere twice to slightly more as long as penultimate antennomere. Terminal maxillary palpomere cultriform. Pronotum subopaque dorsally and on prothoracic hypomeron, flattened in dorsal aspect, elongate elliptical, slightly narrower than head across compound eyes. Anterior margin rounded. Lateral margins constricted laterally posteriad. Dorsal pronotal punctures much larger than those on head, moderately deep. Intervening spaces transversely microstrigose, narrower than punctures. Pronotal dorsal setation dirty yellowish, appressed or nearly so, moderately dense, not concealing dorsal sculpture of pronotum. Base of pronotum with denser, whitish setae. Tactile setae sparse, suberect, not longer than ordinary setae. Scutellar shield small, truncate at posterior margin. Elytron moderately elongate and glossy, slightly, gradually narrows posteriad. Humerus broadly rounded. Postbasal transverse impression not indicated. Punctures on each elytron in anterior half arranged into six incomplete, flat, irregularly shaped and poorly defined rows. Intervening spaces between rows smooth. Elytral setation yellowish, moderately long and dense, directed posteriad, not concealing dorsal sculpture of elytron. Transverse spot of white setae on anterior third and apical third of elytron, not touching suture or lateral margin. Lateral humeral stria not shifted dorsad, not visible in dorsal view. Sutural stria complete, rather broad. Metathoracic wing fully developed. Legs long. Femora clavate. Protarsus elongate, subequal in length to protibia. Tibial terminal spurs paired, serrate. Metatibial spurs long. Basal metatarsomere longer than combined length of remaining tarsomeres. All claws dentate at base. Male tergite VII somewhat narrows towards posterior margin, here slightly emarginate ( Fig. 9 ). Male morphological sternite VII rather short and broad, with paired, short and densely setose lateral prong, posterior margin broadly emarginate between prongs, with row of moderately long and pair of longer setae ( Fig. 10 ). Aedeagus ( Figs 11–12 ) with basale about 3× as long as short apicale, median lobe apically tripartite, apical lobes rounded, paramere rounded apically.

Sexual dimorphism. Female is unknown.

Differential diagnosis. Macratria bimaculosa sp. nov. shares the peculiarly shaped male morphological sternite VII with rather short lateral prongs with its congeners from the gestroi species-group, M. citak Telnov, 2017 (southern lowlands of New Guinea), M. fore Telnov, 2011 (Central Cordillera of New Guinea), M. koiari sp. nov. (described herein; SE New Guinea), M. laszlowagneri Telnov, 2011 (Central Moluccas), M. marind Telnov, 2017 (southern lowlands of New Guinea), M. obiensis Telnov, 2017 (North Moluccas), M. pamelaschmidti Telnov, 2011 ( Solomon Islands), M. pseudodensata Telnov, 2012 (southern lowlands of New Guinea), M. riparia Telnov, 2012 (Raja Ampat Archipelago), and M. subguttata Pascoe, 1860 (North Moluccas). The dorsal vestiture is denser in M. citak , the elytra without white spots, the aedeagus apex different. Macratria koiari sp. nov. (described herein; SE New Guinea) has the transverse band of setae on the basal third of the elytron less conspicuous, not contrastingly whitish, the aedeagus is different in this species and the lateral prongs of the male morphological sternite VII are longer. The male metatibia with modifications in this species and M. laszlowagneri . Macratria marind is brown with reddish head, without white elytral spots, the lateral prong of the male morphological sternite VII distinctly shorter, apically acute. The aedeagus is different and the lateral prong of the male morphological sternite VII comparatively longer in M. obiensis . The metathoracic leg is pale, the head somewhat longer posterior to compound eyes and the male terminal antennomere significantly more elongate in M. pamelaschmidti , the elytra without white spots and same in M. pseudodensata (except for that head base is similarly rounded as that in M. bimaculosa sp. nov.). The lateral prong of the male morphological sternite VII emarginate apically in M. subguttata .

Ecology. Collected on a hot, open riverbank from underside and inside of leaf sheaths of Saccharum sp. reed-like riverside vegetation.

Distribution. Northern lowlands, New Guinea.

Figures

FIGURE 8. Macratria bimaculosa sp. nov., holotype ♁, habitus, dorsal view.

FIGURES 9–12. Macratria bimaculosa sp. nov., paratype ♁. 9—Tergite VII, dorsal view; 10—Morphological sternite VII, ventral view; 11—Aedeagus; 12—Aedeagus, apical portion [not to scale].