Protozantaena Perkins, 1997

Bilton, David T., 2021, Riberazantaena, a new hydraenid genus from the Eastern Arc Mountains of Tanzania (Coleoptera, Hydraenidae), Zootaxa 4999 (6), pp. 573-581 : 574

Protozantaena Perkins, 1997

Protozantaena Perkins, 1997: 174 (type species Protozantaena labrata Perkins , by original designation); Perkins 2009: 41 (partim).

Protozantaena is here redefined and redescribed, following the separation of Riberazantaena gen. nov.

Differential diagnosis. Recognized by the following combination of characters: Body length 1.35–1.75 mm; body form rather flattened; antenna ten-segmented (five + club); maxillary palpi relatively long; no hypomeral carina; hypomeral antennal pocket setae forming a strong cup; ocelli weakly developed, located between the midline and the eyes; pronotum transverse, with anterior hyaline margin and no postocular emarginations; elytral series not striate impressed; tarsi relatively long and aedeagus with reduced parameres, terminal flagellum and additional flagellum and/or distal projections ( Fig. 2A & B ). Distinguished from Parhydraena and Decarthrocerus by the lack of a hypomeral carina, and the very small size. Distinguished from Discozantaena by the very small size, the presence of well-developed hypomeral antennal pocket setae, and the markedly different habitus. Distinguished from Parhydraenopsis by the very small size, the less convex body form, the different elytral puncture pattern, and differences in aedeagal anatomy. Distinguished from Riberazantaena gen. nov. by the relatively long maxillary palpi (palpus length/head width ca. 0.47–0.72), the non-striate impressed elytral series and the presence of (reduced) parameres on the aedeagus.

Redescription. Body size very small, length ca. 1.35–1.75 mm; form elongate oval, weakly to moderately transversely convex dorsally, head not deflexed. Antennomeres ten (five + club), second slightly longer than combined lengths of third to fifth. Maxillary palpi relatively long; palpus length/head width ca. 0.47–0.72. Eyes well-developed, not protuding, 6–8 facets in longest series in dorsal aspect. Labrum set at an angle to clypeus, usually same length or slightly longer than clypeus, shape of anterior margin straight to emarginate. Clypeus anterior margin and frontoclypeal suture slightly arcuate. Ocelli weakly convex, located midway between midline and eyes. Frons very weakly convex between ocelli; area behind and between ocelli lacking carinae. Pronotum with anterior and posterior shallow transverse impressions on disc, posterior impression usually U-shaped; anterior hyaline border present over median third, extremely narrow. Hypomeron lacking carina at margin of hydrofuge pubescence; antennal pocket bordered by row contiguous, arcuate setae forming strong cup, numbering ca. 12–18. Proventral antennal cleaner, a dense cluster of sharp spines, located on anterolateral margin of each side of proventrite. Metaventrite with shallow impression on disc in basal 1/2, and often with midlongitudinal carina between impression and mesoventral intercoxal process. Each elytron with ten rows of punctures, six between suture and humerus; serial punctures deeper and larger than punctures on intervals, but never striate-impressed, setae slender and usually very short. Intercoxal sternite small, triangular. Aedeagus ( Fig. 2A & B ) with gonopore at tip of long, rigid flagellum and additional distal flagellum and/or process; parameres reduced, each with two setae.

Figures

FIGURE 2. Aedeagi of A) Protozantaena labrata, modified from Perkins (2009); B) Protozantaena palpalis, modified from Perkins (2009); C) Riberazantaena grebennikovi, Uluguru Mountains, Tanzania; D) Riberazantaena latissima sp. nov., Chome Forest, South Pare Mountains, Tanzania. Scale bar = 0.1 mm. Note that the flagella of P. labrata and Riberazantaena spp. are flexible, meaning that curvature etc. is not diagnostic.