Troglochares Spangler, 1981

Giron, Jennifer C. & Short, Andrew Edward Z., 2021, The Acidocerinae (Coleoptera, Hydrophilidae): taxonomy, classification, and catalog of species, ZooKeys 1045, pp. 1-236 : 1

Genus Troglochares Spangler, 1981 Figs 6 , 56

Troglochares Spangler, 1981a: 316.

Gender.

Masculine.

Type species.

Troglochares ashmolei Spangler, 1981a: 318; by original designation and monotypy.

Diagnosis.

Small beetles, body length 1.9 mm. Body shape oval in dorsal view; moderately convex in lateral view ( Hansen 1991: fig. 39). Color yellowish light brown; ground punctation extremely shallowly marked. Shape of head somewhat oval. Eyes absent (Fig. 56B ). Clypeus trapezoidal, with anterior margin broadly emarginate, with medial region of emargination nearly straight (Fig. 56B ). Labrum fully exposed, convex. Mentum rather smooth and antero-medially depressed; median anterior depression broad. Antennae with nine antennomeres ( Spangler 1981a: fig. 3); cupule slightly asymmetric, with rounded outline. Maxillary palps slender, nearly as long as width of head; inner margin of maxillary palpomere 2 nearly straight, outer margin curved along apical third; maxillary palpomere 3 slightly shorter than 4. Prosternum non carinate, slightly convex. Elytra without sutural striae; ground punctation fine, shallow; outer margins slightly flared (Fig. 56A ). Posterior elevation of mesoventrite with curved, transverse ridge ( Spangler 1981a: fig. 8); anapleural sutures concave, separated at anterior margin by distance 0.7 × width of anterior margin of mesepisternum. Metaventrite densely pubescent except for median short and narrow posterior glabrous patch; metaventrite short (nearly as long as first abdominal ventrite; Spangler 1981a: fig. 8). Protibiae with spines of anterior row long; apical spurs of protibiae moderately slender, reaching apex of protarsomere 2; metatarsomeres 2-4 slightly decreasing in size; metatarsomere 5 nearly as long as 2-4 combined. Posterior femora densely covered by hydrofuge pubescence along basal 2/3 ( Spangler 1981a: fig. 8). Fifth abdominal ventrite apically truncate, without stout setae ( Spangler 1981a: fig. 9).

Differential diagnosis.

Troglochares is the only genus of acidocerines (and Hydrophilids) lacking eyes.

Distribution.

Neotropical: Ecuador; Fig. 6 .

Natural history.

The only known specimen was collected in a cave on calcite formations and is presumably aquatic ( Spangler 1981a).

Larvae.

The immature stages are unknown for Troglochares .

Taxonomic history.

The genus and its only known species were described by Spangler (1981a).

Remarks.

The genus is only known from a single female specimen, which is pin-mounted in pieces (Fig. 56 ). This species was not included in the molecular phylogeny by Short et al. (2021). Its assignment to the Tobochares group is based primarily on its tiny size (excluding the Helochares group), presence in the Neotropical region (excluding the Agraphydrus group), and lack of a sutural stria (excluding the Primocerus and Chasmogenus groups).

Species examined.

The holotype specimen of Troglochares ashmolei Spangler was examined.

Selected references.

Spangler 1981a: original description; Short et al. 2021: morphological affinities discussed in a phylogenetic context.

Figures

Figure 6. Known distribution of genera of Acidocerinae: Novochares, Peltochares, Primocerus, Quadriops, Radicitus, Sindolus, Tobochares, and Troglochares.

Figure 56. Holotype and labels of Troglochares ashmolei A mount of holotype B head, dorsal view C labels.