Macratria sentani, 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 : 36-39

Macratria sentani sp. nov.

urn:lsid:zoobank.org:act:995FE30E-B1BE-418D-98FA-A90DC1EC623F

( Figs 90–100 )

Type material designated. Holotype ♂ NME: INDONESIA E, New Guinea, Papua Prov., Sentani , between the airport and the lake, 02°35’14’’S 140°32’01’’E, 80 m, 30.III.1998, sago swamp, from Metroxylon leaves [printed]. Antennomeres 8–11 of the left and 6–11 of the right antenna, the left protibia- and tarsus and the left metatarsus are missing.

Paratypes 2 specimens. 1♂ & 1♀ DTC: same label as holotype.

Derivatio nominis. Toponymic. Named after the Lake Sentani and the Sentani language. Noun in apposition.

Measurements, holotype male, total body length 4.4 mm; head length 0.9 mm, head width across compound eyes 0.65 mm, pronotal length 1.1 mm, maximum pronotal width 0.6 mm, elytral length 2.4 mm, combined maximum elytral width 0.9 mm. Male paratype 4.2 mm, female paratype about 4.1 mm long.

Description. Male ( Figs 90–92 ). Dorsum nearly uniformly black. Cranial ‘neck’, prothoracic hypomeron, sterna and abdominal ventrites reddish brown to black-brown. Mouthparts including maxillary palpi yellow and antennomeres 1–6 yellow, remaining antennomeres yellowish-brown (antennomere seven) to brown (antennomeres 9–11 not available for study). Pro- and mesothoracic femur yellow, coxa and trochanter reddish brown, corresponding tibia yellowish brown to brown, tarsus yellow. Metathoracic leg brown, anterior margin of femur somewhat paler. Head glossy dorsally and ventrally, strongly elliptical, distinctly narrows towards base. Frons narrow, slightly less half as wide as dorsal eye length. Compound eye large, occupying most of lateral side of head beyond antennal insertion, moderately protruding from lateral outline of head. Interfacetal setae moderately long, moderately dense. Tempus strongly constricted towards head base, about half as long as dorsal eye length. Frontoclypeal suture or impression not observed. Head dorsal punctures variably large but generally small and shallow, less dense on median area of frons. Intervening spaces smooth, narrower than to 3× as wide as punctures. Head dorsal setae white, appressed, moderately dense, directed in part transversely, in part obliquely laterally. Tactile setae sparse, erect, longer than ordinary setae. Antenna slender and strongly filiform (length unknown since terminal antennomeres missing in both types). Basal antennomere elongate, about 1.5–1.6× as long as antennomere two. Antennomere three slightly longer than antennomere two, slightly shorter than antennomere four. Antennomeres 3–7 long and slender, antennomere eight somewhat widened distally. Terminal maxillary palpomere cultriform. Pronotum glossy dorsally and on prothoracic hypomeron, flattened in dorsal aspect, elongate cylindrical, narrower than head across compound eyes. Anterior margin narrow, subtruncate. Lateral margins constricted laterally anteriad. Dorsal pronotal punctures small to larger than those on head, moderately deep. Intervening spaces smooth to transversely microstrigose, generally as wide as to twice as wide as punctures. Pronotal dorsal setation double, not fully concealing dorsal sculpture of pronotum. Whitish setae are thicker, denser and appressed, yellowish setae are thinner, subdecumbent, sparser, directed posteriad. Tactile setae sparse, erect, longer than ordinary setae, arranged mainly at pronotal base. Scutellar shield small, truncate at posterior margin. Elytron elongate, glossy, 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 minutely punctate and (in part) microstrigose. Elytral setation yellowish, moderately long and dense, directed posteriad, not concealing dorsal sculpture of elytron. Those setae adjacent to suture directed slightly obliquely laterally. An irregular, poorly defined spot of white setae on anterior third and apical third of elytron, not touching suture. Whitish setae intermixed with ordinary yellow ones. Lateral humeral stria shifted dorsad, more or less visible in dorsal view. Sutural stria complete, rather broad. Metathoracic wing fully developed. Legs long. Male mesotibia at inner margin with series of peculiar, long, somewhat sinuous setae ( Fig. 92 ). Tibial terminal spurs paired, serrate. Metatibial spurs long. Basal metatarsomere distinctly longer than combined length of remaining tarsomeres. All claws strongly dentate at base. Male tergite VII elongate, narrows posteriad, narrowly rounded at posterior margin ( Fig. 93 ). Male morphological sternite VII ( Fig. 94–95 ) short and broad, with long, sinuous, laterally and apically densely setose, paired lateral prong provided with short, apically broadly rounded ventral lobe at apex. Posterior margin between lateral prongs strongly produced posteriad, deeply emarginate, provided with several moderately long setae. Tergite VIII and morphological sternite VIII as in Fig. 96 . Aedeagus ( Figs 97–98 ) long, moderately broad, basale more than twice as long as narrow apicale. Paramere narrow, laterally subparallel, apically asymmetrically rounded. Median lobe tripartite apically.

Sexual dimorphism. Female externally closely similar to male (terminal antennomeres not available in the only studied specimen). Tergite VII narrowly rounded at posterior margin ( Fig. 99 ), morphological sternite VII subtriangular, rounded medially at posterior margin ( Fig. 100 ).

Differential diagnosis. Macratria sentani sp. nov. shares conically protruding head base with the gestroi species-group congeners, in particular M. coniceps Pic, 1900 (Aru Islands), M. eparaksts Telnov, 2017 (southern New Guinea), M. ronaldi Telnov 2011 (Bird’s Neck Isthmus, New Guinea), some specimens of M. subguttata Pascoe, 1860 (North Moluccas: Bacan, Halmahera, Ternate), M. spatulatocarinata and M. tigrina spp. nov. (two latter described herein from northern New Guinea) and differs in the shape of the male terminalia and aedeagus, the simple metatibial spurs (the inner metatibial spur spatulate in M. spatulatocalcarata spp. nov.), the sparser punctured pronotal disc, and the peculiarly setose inner margin of the male mesotibia, and the apically lobate lateral prong of the male morphological sternite VII (the prong is lobate-angulate medially at outer margin in M. ronaldi ). Male remains unknown for M. coniceps , this species is considered different from M. sentani sp. nov. in the more regularly elliptical shape of the pronotum (the pronotum distinctly constricted anteriad in M. sentani sp. nov.), the dark-coloured femora and tibiae, the comparatively less elongate, and the hardly narrowed elytron. The head is less strongly elongate compared to the of the male M. tigrina sp. nov.

Ecology. Collected from leaves of sago palm ( Metroxylon sagu ) in a hot, open, swampy area at Sentani lakeside.

Distribution. Northern lowlands, New Guinea.

Figures

FIGURES 90–92. Macratria sentani sp. nov., holotype ♁. 90—Habitus, dorsal view; 91—Same, head (dorsal view) and pronotum (lateral view); 92—Left metatibia, dorsal view [not to scale].

FIGURES 93–100. Macratria sentani sp. nov. 93—Paratype ♁, tergite VII, dorsal view; 94—Same, morphological sternite VII, ventral view; 95—Same, morphological sternite VII, apices of lateral prongs and median part of posterior margin, ventral view; 96—Same, morphological tergite VIII and morphological sternite VIII, ventral view; 97—Same, aedeagus; 98—Same, aedeagus, apical portion; 99—Paratype ♀, tergite VII, dorsal view; 100—Same, morphological sternite VII, ventral view [not to scale].