Phaenonotum rotundulum Sharp, 1882

Deler-Hernandez, Albert & Fikacek, Martin, 2016, Redescriptions and lectotype designations of Central American species of Phaenonotum Sharp (Coleoptera, Hydrophilidae) based on the type material from the David Sharp collection, ZooKeys 579, pp. 83-98 : 90-91

Taxon classification Animalia Coleoptera Hydrophilidae

Phaenonotum rotundulum Sharp, 1882 Figures 1e, 2d, 3d, 4f

Phaenonotum rotundulum Sharp, 1882: 100.

Type material examined.

Lectotype (hereby designated): male (BMNH): " Phaenonotum rotund– / ulum. / Type D.S. / S. Geronimo. Guatema– / la. Champion // San Geronimo, / Vera Paz. / Champion. // B.C.A. I. 2. / Phaenonotum / rotundulum , / Sharp. // Sharp Coll. / 1905.-313. // Type / H.T. [round label with red margins]." We remounted the specimens, the abdomen is glued separately, and the aedeagus is embedded in a Euparal slide attached to the same pin. Paralectotypes: 1 unsexed specimen (BMNH): " Phaenonotum / rotundulum / D.S. / El Zumbador. / 2500 ft. Guate– / mala. Champion. // El Tumbador, / Guatemala. / Champion. // B.C.A. I. 2. / Phaenonotum / rotundulum , / Sharp. // Sharp Coll. / 1905.-313.". 1 unsexed specimen (BMNH): " Phaenonotum / rotundulum / D.S. / Chacoj. Guatema / la. Champion // Chacoj, / R. Polochic, / Guatemala. / Champion // B.C.A. Col. I. 2. / Phaenonotum / rotundulum , / Sharp.". 2 females (BMNH): same label data as the lectotype.

Other type material.

Sharp (1882) also examined specimens from Mexico: Cordova, Toxpam, Guatemala: San Juan, San Joaquin, Zapote, and Panama: Volcan de Chiriqui, 4000 to 6000 feet, all of which have to be considered as paralectotypes. We did not examine these specimens.

Type locality

(following lectotype designation). San Geronimo, Guatemala.

Redescription.

Habitus as in Figs 1e and 2d. Body length approximately 2.8-3.3 mm (lectotype: 3.3 mm). Body form oval in dorsal view (Fig. 1e), elytra highly and evenly convex in lateral view (Fig. 2d). Dorsal surface reddish brown (Fig. 1e). Antennae and maxillary palpi testaceous. Ventral surface reddish brown. Leg reddish, tarsomeres yellowish. Head with fine and sparse punctures. Pronotum with punctures of same size as on head. Elytral punctation strongly impressed, much coarser than on pronotum and head. Epipleura very broad throughout. Meso- and metaventral processes fused into a common keel; mesoventral process arrow-head shaped with indistinct hood, its base as wide as apex of metaventral process, metaventral process wide basally, strongly narrowing anteriad and hence triangular in shape, length of metaventrite medially (including metaventral process) ca. three time longer than mesoventral process; metathoracic discrimen weakly developed (Fig. 3d). Profemora with long sparse pubescence in basal 0.75. All tarsi with long setae on ventral surface. Aedeagus (Fig. 4f) 0.5 mm long, with median lobe not reaching apices of parameres; basal portion of median lobe curved laterally, apical portion widely rounded, median lobe narrowing towards apex; shape of the gonopore oval. Parameres slightly sinuate in median region. Phallobase not examined in detail.

Comments on lectotype designation.

Our request to borrow the Sharp specimens of Phaenonotum rotundulum resulted in the receipt of the above five specimens. These specimens, however, clearly represent only a smaller part of the type series, as many other localities were mentioned in the original description by Sharp (1882). All specimens examined agree with the data provided in the original description, and hence are clearly part of the type series. In order to fix the identity of the species for future studies, we are designating the dissected male labeled as “Type” as the lectotype of Phaenonotum rotundulum .