Diatrichalus manokwarensis, Bocek, Matej, 2017

Bocek, Matej, 2017, New species of Diatrichalus (Coleoptera: Lycidae) from New Guinea and the Moluccas, Zootaxa 4247 (5), pp. 577-584 : 580

Diatrichalus manokwarensis sp. n.

( Figs 3 , 9–10 )

Type material. Holotype, male, New Guinea, West Papua, Manokwari district, Arfak Mts., Maibri village , 1570 m (BM0079; LMBC).

Diagnosis. D. manokwarensis sp. n. resembles other uniformly black colored Diatrichalus species from New Guinea, but it differs in the unique, widely rounded apical part of the phallus ( Figs 9–10 ).

Description. Male. Body medium sized, slender, with parallel-sided elytra. Whole body uniformly black, only elytra slightly lighter, dark brown ( Fig. 3 ). Head small, cranium covered with short pubescence, eyes large, hemispherically prominent, eye diameter 1.23 times longer than interocular distance; antennal tubercles flat, antennae slender, serrate. Pronotum transverse, 1.5 times wider than long at midline, lateral margins elevated with distinct protuberance and with vestiges of lateral carinae, disc pubescent. Elytra slender, 3.51 times longer than width at humeri, with robust primary costae, secondary costae completely absent ( Fig. 3 ), costa 3 substantially shortened at elytral apex, reticulate cells regular, mostly rectangular. Phallus slender basally, with widely rounded, prolonged apex; phallobase mostly membranous, with very slender, moderately sclerotized ring of phallobase ( Figs 9–10 ).

Measurements. BL 7.8 mm, WH 1.74 mm, PL 0.76 mm, PW 1.14 mm, Edist 0.45 mm, Ediam 0.54 mm.

Etymology. The species is named after the type locality.

Distribution. New Guinea, Papua Barat, Manokwari district.

Remark. A high number of Diatrichalus species from whole New Guinea is darkly colored and several of them, i.e. D. biroi Kleine , D. wauensis Bocak and D. xylobanoides Kleine , have only four longitudinal costae on elytra. Similarly, D. manokwarensis sp. n. does not have secondary costae, but its distant relationship to other species with four costae is suggested by the unique shape of male genitalia. Without further information, detailed phylogenetic relationships of these species remain open. Elytral costae have a strengthening function and their number is regularly lower in the species with slender body. It is worth to note, that the very high plasticity in the number of elytral costae was demonstrated in other Metriorrhynchini ( Sklenarova et al. 2014). Although this characters has been widely used by previous authors for the delimitation of genera, recent study proved their multiple origins and a low value for higher classification.

Figures

FIGURES 2 – 6. General appearance of Diatrichalus. 2 — D. buruensis sp. n., male; 3 — D. manokwarensis sp. n., male; 4 — D. mindikensis sp. n., male; 5 — D. robustus sp. n., male; 6 — D. mancus, male. Scales 2 mm.

FIGURES 7 – 24. Male genitalia (ventral and lateral views, respectively). 7, 8 — D. buruensis sp. n.; 9, 10 — D. manokwarensis sp. n.; 11, 12 — D. mindikensis sp. n.; 13, 14 — D. robustus sp. n.; 15, 16 — D. mancus; 17, 18 — D. dilatatus; 19, 20 — D. sinuaticollis; 21, 22 — D. xylobanoides; 23, 24 — D. niger. Scales 0.5 mm.