Macratria ripicola, 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 : 28-30

Macratria ripicola sp. nov.

urn:lsid:zoobank.org:act:E00B791D-54E3-4735-B41C-3092A16CD38E

( Figs 70–77 )

Type material designated. Holotype ♂ NME: INDONESIA E, New Guinea, Papua Prov., Bonggo 26 km SE, Toareng River , 02°25’15’’S 139°46’25’’E, 25 m, 28.III.1998, river valley, from riverside vegetation [printed].

Paratypes 7 specimens. 1♀ NME & 1♀ DTC: same label as holotype; 3 specimens NME & 2 specimens DTC: INDONESIA E, New Guinea, Papua Prov., Bonggo 2 km E, Kiren vill. env, 02°17’22’’S 139°33’32’’E, 40 m, 28.III.1998, valley of muddy river, from riverside vegetation [printed] .

Derivatio nominis. Named from Latin “ripicola ” (riverine, riparian) to point on the habitat of this species.

Measurements, holotype male, total body length about 3.8 mm; head length 0.7 mm, head width across compound eyes 0.65 mm, pronotal length 0.95 mm, maximum pronotal width 0.7 mm, elytral length 2.2 mm, combined maximum elytral width 1 mm.

Description. Male ( Fig. 70 ). Head dark red to brown, dorsum and venter uniformly black-brown, elytra noncontrastingly paler brown along suture. Mouthparts including maxillary palpi, antennomeres 1–8, anterior and middle legs yellowish orange, metathoracic leg brown. All coxae and trochanters brown. Head subopaque dorsally and ventrally, nearly circular. Frons moderately narrow, about 0.7× as wide as dorsal eye length. Compound eye large, occupying nearly whole lateral side of head beyond antennal insertion, moderately protruding from lateral outline of head, about 4× as long as rounded, short tempus. Interfacetal setae moderately long, dense. Head base broadly rounded to subtruncate, medially broadly, shallowly notched. Frontoclypeal suture or impression not observed. Head dorsal punctures dense, moderately deep. Intervening spaces smooth, narrower than to as wide as punctures. Head dorsal setae dirty yellowish, subdecumbent, moderately long and dense, not concealing dorsal surface of head. Tactile setae sparse, erect, not longer than ordinary setae, mainly arranged on head base. Antenna slender and strongly filiform, slightly thickened at apex, hardly extending towards base of pronotum when directed posteriad. Basal antennomere elongate, about 1.5× as long as antennomere two. Antennomere three slightly longer than as antennomere two, about as long as antennomere four. Antennomeres 3–8 elongate, 9–10 widened distally. Terminal antennomere moderately long, acutely pointed, about 1.4–1.6× as long as penultimate antennomere. Terminal maxillary palpomere cultriform. Pronotum subopaque dorsally, flattened in dorsal aspect, broadly elliptical, wider than head across compound eyes. Anterior margin broad, rounded. Lateral margins constricted laterally posteriad. Dorsal pronotal punctures much larger and denser than those on head, moderately deep. Intervening spaces somewhat raised, microcorrugate, much narrower than punctures. Pronotal dorsal setation dirty yellowish, moderately long and dense, subdecumbent, not fully concealing dorsal sculpture of pronotum. Tactile setae not observed. Scutellar shield small, truncate at posterior margin. Elytron moderately elongate, subopaque, gradually, hardly narrows posteriad. Humerus broadly rounded. Postbasal transverse impression not indicated. Punctures on each elytron in anterior half arranged into six incomplete, poorly defined, flat, irregularly shaped rows. Intervening spaces between rows smooth to minutely punctate. Elytral setation dirty yellowish, moderately long, dense, directed posteriad, effectively concealing dorsal sculpture of elytron. Lateral humeral stria somewhat shifted dorsad but not visible in dorsal view. Sutural stria complete, rather broad. Metathoracic wing fully developed. Legs moderately long, stout. Femur clavate. Protarsus somewhat elongate, subequally long to protibia. Tibial terminal spurs paired, moderately long, margins serrate. Basal metatarsomere shorter than combined length of remaining tarsomeres. All claws strongly dentate at base. Male tergite VII shallowly emarginate at posterior margin ( Fig. 71 ). Male morphological sternite VII broadly and deeply emarginate at posterior margin, with a group of long setae on both sides of emargination ( Fig. 72 ). Tergite VIII, morphological sternites VIII and IX as in Fig. 73 . Aedeagus ( Figs 74–75 ) long and slender, basale more than 3× as long as short apicale, with short and apically rounded (especially, in lateral aspect) paramere. Median lobe quadripartite apically, outer pair of apical lobes longer and much slenderer than inner pair.

Sexual dimorphism. Female externally similar to male, pronotum comparatively stronger widened in anterior part, terminal antennomere about 1.8× as long as penultimate antennomere. Female tergite VII rounded at posterior margin ( Fig. 76 ), morphological sternite VII subtriangular, medially rounded at posterior margin ( Fig. 77 ).

Differential diagnosis. Macratria ripicola sp. nov. appears similar to several black or brown Papuan congeners and is primarily different in the peculiar shape of the apicale of the male aedeagus in the combination with the apically broadly emarginate male morphological sternite VII, the comparatively short male terminal antennomere and the length ratio of the terminal versus penultimate antennomere being greater in female than in male, which is rather unique for the genus.

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 70. Macratria ripicola sp. nov., holotype ♁, habitus, dorsal view.

FIGURES 71–77. Macratria ripicola sp. nov. 71—Holotype ♁, tergite VII, dorsal view; 72—Same, morphological sternite VII, ventral view; 73—Same, morphological tergite VIII, morphological sternites VIII and IX, ventral view; 74—Same, aedeagus; 75—Paratype ♁, aedeagus, apical portion; 76—Paratype ♀, tergite VII, dorsal view; 77—Same, morphological sternite VII, ventral view [not to scale].