Iviephengus, Roza, 2023

Roza, André Silva, 2023, A new genus and a new species of railroad-worm beetle from Peru (Coleoptera, Phengodidae, Mastinocerinae), European Journal of Taxonomy 864 (1), pp. 64-76 : 66-68

Genus Iviephengus gen. nov.

urn:lsid:zoobank.org:act:8E421AB8-7EE1-4492-92A8-2D74E89A462A

Figs 1–5

Type species

Iviephengus ferreirai gen. et sp. nov., here designated.

Diagnosis

Interantennal distance close to 3× the antennal socket length ( Figs 1D , 2A ); antenna 12-segmented, IV to XI each with two long symmetrical compressed and apically slightly enlarged branches, longer than respective antennomere ( Fig. 2G ); labrum fused to frontoclypeus ( Fig. 2A ); mandible short, not projecting and obliquely crossed, each with a notch on the external margin to fit the other mandible and without extra teeth ( Fig. 2H–I ); maxillary palpi 4-segmented, last segment digitiform ( Fig. 2J ); labial palpi 2-segmented ( Fig. 2K ); posterior tentorial pit consisting of a single small fossa ( Fig. 2B ); elytron around 2.5× longer than wide, slightly convergent posteriorly and slightly thickened apically ( Fig. 1A ); wing with radial cell closed and transverse, vein r4 interrupted, r3 absent ( Fig. 1E ); first tarsomere of pro- and mesotarsus with a ventral comb covering the posterior half of the tarsomere ( Fig. 3A–B ); claws simple, without any teeth ( Fig. 3C ); aedeagus with paramere symmetrical, apex unevenly round, toothed inward, with short and sparse bristles ( Fig. 4D, G–H ).

Etymology

The name is in honour of the entomologist Michael Ivie, a great Coleoptera researcher who has contributed largely to the knowledge of world beetles, including phengodids, with a major focus on morphology and taxonomy. Michael kindly received me during my visit to the Montana State University and allowed the loan of several Phengodidae specimens. The suffix phengus is found in several Phengodidae genera. Singular genitive, masculine.

Description

Male

HEAD ( Figs 1D , 2 ). Head wider than long, with posterior margin subparallel, slightly convergent posteriorly, usually covered by pronotum, as wide as the pronotum; antenna slightly longer than elytron; 12-segmented, antennomeres IV–XI with two symmetrical compressed and apically slightly enlarged branches, longer than respective antennomere ( Fig. 2G ); eyes moderately protruding, finely faceted ( Fig. 2A–F ), frontoclypeus with a declivity between the antennae before labrum, interantennal space close to 3 × antennal socket width; labrum small, fused with frontoclypeus but with vestigial lateral sutures, bilobate ( Fig. 2A ); mandibles moderately long, continuously tapered towards the apex, around 4× longer than basal width, slightly projected and obliquely crossed, with an external notch to fit the other mandible ( Fig. 2H–I ); maxilla with palpi 4-segmented, last palpomere digitiform, palpifer distinct, galea distinct, extremely short and free, highly setose, lacinia almost fused with the stipe, highly setose, cardo semitriangular, 2× as wide as long ( Fig. 2J ); labium with palpi 2-segmented, short, not covered by mandibles, last palpomere digitiform, ligula absent, prementum oval, palpiger absent, mentum and submentum fused in a single piece, which is fused with the head ( Fig. 2K ); one gular suture, tentorial pit with single fossa ( Fig. 2B ).

THORAX ( Figs 1A–D , 3 ). Pronotum trapezoidal, slightly wider than long, anterior angles dorsally concave, rounded, lateral margins subparallel, laterally curved down in the anterior angles ( Fig. 1D ); elytron surpassing the fourth abdominal segment, around 2.5× as long as wide, wider in anterior half, slightly convergent posteriorly, subparallel, apex slightly swollen ( Fig. 1A ); posterior wings with radial cell closed, moderately elongated and transverse, around 2.5 × as wide as long, r4 interrupted both in the radial cell and RP, r3 absent, RP reaching one third of MP1+2 length, medial field containing five main veins: MP3, MP4, CAS and AA4; CuA1 and CuA2 absent, anal lobe well developed, AP3+4 long, J absent ( Fig. 1E ); legs increasing in length from proleg to metaleg, pro- and mesotarsomere I with a ventral comb covering the posterior half of the tarsomere ( Fig. 3A–B ), protarsomere I 2× as long as II, II–IV decreasing in length, tarsomere IV of all legs with ½ V length, claws simple, without any teeth ( Fig. 3C ).

ABDOMEN ( Fig. 4 ). Subparallel, tergites and ventrites extremely transverse, around 3–4 × as wide as long, slightly increasing in length from the first to the last, tergite VIII as wide as long; tergites with anterior margin slightly emarginate, lateral margins subparallel, posterior margin straight to slightly rounded ( Fig. 4A ); tergite IX transverse, with a membranous division in the middle, anterior margin oblique inward, posterior margin curved inwards; tergite X short, conical, lateral margins subparallel ( Fig. 4E ); sternites each with anterior margin straight, lateral margins subparallel, posterior margin straight to slightly rounded ( Fig. 4B ), sternite VIII with a membranous, densely setose projection on anterior margin ( Fig. 4C ), sternite IX elongate, posterior margin slightly emarginate ( Fig. 4F ); aedeagus trilobed, basal piece attached to the median lobe, feebly sclerotized, and shaped as a ribbon-like stripe, median lobe cylindrical, strongly curved at base, rounded apically; flagellum encircled around median lobe at rest; about 2 × as long as median lobe length; parameres symmetrical, narrowing slightly past the middle towards the apex, which is truncate, toothed inward, with short and sparse bristles ( Fig. 4D, G–H ).

Female and immature stages

Unknown.

Biology and distribution

No specimens of Iviephengus gen. nov. were seen alive, so there is no data regarding their habits. The genus is only known to occur in the Peruvian Amazon. All specimens were collected in March, the end of the summer in the southern hemisphere.

Remarks

Iviephengus gen. nov. can easily be separated from most of the genera of Mastinocerinae by the presence of a ventral comb in the pro- and mesotarsomere I. When compared with other genera with combs on pro- and mesotarsomere I, it can be separated from all of them, with the exception of Cephalophrixothrix Wittmer, 1976 , by the comb covering half of the ventral pro- and mesotarsomere I (vs covering the entire ventral pro- and mesotarsomere I in the other genera). It can be differentiated from Cephalophrixothrix by the mandible with a notch on the external margin to fit the other mandible (vs without a notch in Cephalophrixothrix ), the labial palpi with two palpomeres (vs three in Cephalophrixothrix ), and the tarsomere II half the length of tarsomere I (vs subequal to tarsomere I length in Cephalophrixothrix ).

Figures

Fig. 1. Iviephengus ferreirai gen. et sp. nov. A–D. Holotype, ♂ (MUSM). A. Habitus, dorsal. B. Habitus, lateral. C. Habitus, ventral. D. Head and pronotum, lateral. E. Paratype, ♂ (DZRJ). Posterior wing, dorsal.

Fig. 2. Iviephengus ferreirai gen. et sp. nov., paratype, ♂ (DZRJ). A. Head, dorsal. B. Head, ventral. C. Head, frontal. D. Head, lateral. E. Head, posterior. F. Head, occipital. G. Antenna, lateral. H. Left mandible, dorsal. I. Left mandible, frontal. J. Maxilla, ventral. K. Labium, ventral.

Fig. 3. Iviephengus ferreirai gen. et sp. nov., paratype, ♂ (DZRJ). Scanning electron micrographs. A. Protarsus, lateral. B. Protarsus, protarsomere I, comb, ventral, detail. C. Protarsus, claw, frontal.

Fig. 4. Iviephengus ferreirai gen. et sp. nov., paratype, ♂ (DZRJ). A. Abdomen, dorsal. B. Abdomen, ventral. C. Sternites VII and VIII, ventral. D. Aedeagus, lateral. E. Tergites IX and X, dorsal. F. Sternite IX, ventral. G. Aedeagus, dorsal. H. Aedeagus, ventral.

Fig. 5. Distribution (type locality) of Iviephengus ferreirai gen. et sp. nov.