Zimpherus Miller and Wheeler

Miller, Kelly B. & Wheeler, Quentin D., 2015, Zimpherus nancaeMiller and Wheeler (Coleoptera: Dytiscidae: Hydroporinae: Bidessini), New Genus and New Species from Venezuela, The Coleopterists Bulletin 69 (3), pp. 507-511 : 508

Zimpherus Miller and Wheeler , new genus ( Figs. 1–7 )

Type Species. Zimpherus nancae Miller and Wheeler , new species, by present designation.

Diagnosis. This species is diagnosed within Bidessini by: 1) a transverse occipital line on the head absent ( Fig. 1 ); 2) the anterior clypeal margin unmodified ( Fig. 1 ); 3) a transverse carina across the elytral epipleuron at the humeral angle absent ( Fig. 1 ); 4) basal elytral stria present ( Fig. 1 ); 5) elytral sutural stria absent ( Fig. 1 ); 6) the elytron without rows of punctures ( Fig. 1 ); 7) the median lobe of the male aedeagus apically extremely complex ( Figs. 2, 3 ); and 8) the lateral lobes of the male aedeagus with two segments and apically rounded ( Fig. 4 ). The genus is similar to Uvarus , but differs in the body shape and the shape of the male aedeagus. The overall body shape of Zimpherus specimens is narrow and anteriorly narrowed with the head somewhat deflexed ventrad and the lateral outline distinctly discontinuous between the pronotum and elytron ( Fig. 1 ). The body shape in Uvarus specimens is broadly to elongate oval and the lateral outline is approximately continuous between the pronotum and elytron. The median lobe is apically multifurcated and multilobed in Zimpherus ( Figs. 2, 3 ), and the lateral lobe is broad with the apex rounded, without a small, curved, tooth–shaped apical lobe ( Fig. 4 ). A simple, evenly curved male median apical lobe is characteristic of Uvarus . The male median lobe of members of Microdessus is also apically divided into multiple lobes (four), but Microdessus species are very small (∼ 1.5 mm), do not have an unusually offset metatrochanter, and are not overall uniquely shaped as are Zimpherus specimens. Microdessus species are somewhat flattened dorsoventrally and elongate oval with the lateral margins continuously curved.

Etymology. The genus is named in honor of Nancy Zimpher, Chancellor of the State University of New York.

Discussion. This genus bears similarity with both Uvarus and Microdessus in its basic character combination but differs from each (see Diagnosis). Nevertheless, it is not without some misgivings that the new species described here is placed within a new genus given the expanding number of genera in the tribe.

Figures

Fig. 1. Zimpherus nancae, dorsal habitus. Scale bar =

Figs. 2–6. Zimpherus nancae. 2–4) Male genitalia: 2) Median lobe, right lateral aspect; 3) Right lateral lobe, right lateral aspect; 4) Median lobe, ventral aspect; 5) Left metatrochanter, anterior aspect. 6) Prosternal process. Scale bars: A = 0.5 mm for Fig. 5; B = 0.2 mm for Fig. 6.

Fig. 7. Zimpherus nancae, distribution (type locality).