Hydraena mintrita, Perkins, Philip D., 2011

Perkins, Philip D., 2011, New records and description of fifty-four new species of aquatic beetles in the genus Hydraena Kugelann from South America (Coleoptera: Hydraenidae), Zootaxa 3074, pp. 1-198 : 27

Hydraena mintrita , new species

Figs. 31 (habitus), 33 (aedeagus), 160 (female abd.), 168 (spermatheca), 195 (map)

Type Material. Holotype (male): Venezuela : Monagas, stream nr. San Antonio, elev. 557 m, 10° 6.596' N, 63° 44.059' W, 1 ii 2010, Short, Garcia, Joly (VZ10-0201-02A). Deposited in the MIZA. Paratypes: Same data as holotype (3 SEMC).

Differential Diagnosis. A medium sized species with a distinct pronotal macula and, in males, with a large, concave pronotal scintilla (the pronotal scintilla is much smaller in females). There is not a distinct difference in the sizes of pronotal punctures on the disc versus those surrounding the disc. The aedeagus can perhaps be compared with that of H. scintillarca , but the two differ markedly in many details ( Figs. 33, 38). H. mintrita is a smaller species (ca. 1.36 mm vs. 1.73 mm) with less arcuate sides of pronotum and elytra; additionally, the mesoventral intercoxal process (P2) and the metaventral plaques are relatively wide in H. mintrita , whereas in H. scintillarca P2 is narrow, and the plaques are carinate ( Figs. 31 , 36 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.36/0.57; head 0.20/0.34; pronotum 0.32/0.45, PA 0.37, PB 0.44; elytra 0.84/0.57. Dorsum of head dark brown to piceous; pronotum testaceous around subrectangular piceous macula, ratios of color bands, as measured in midline, ca. 6/11/5; elytra dark brown; legs light brown; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 1xef, slightly denser near eyes than medially; interstices laterally microreticulate, dull, ca. 0.5–1xpd, medially effacedly microreticulate, weakly shining, ca. 1xpd. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining; postmentum very finely densely micropunctulate, dull. Genae raised, shining, without posterior ridge.

Pronotum weakly arcuate laterally; anterior margin straight behind eyes, emarginate behind frons except slightly produced at distinct, large, concave scintilla; punctures on disc much larger and deeper than those on frons, interstices weakly shining, 1–2xpd on disc, punctures not appreciably larger and slightly denser at anterior and posterior; PF1 absent; PF2 very shallow, obsolete; PF3 moderately deep; PF4 absent.

Elytra weakly arcuate laterally; summit of posterior declivity slightly behind midlength; lateral explanate margins narrow; on basal 1/3 punctures slightly smaller than largest pronotal punctures, punctures becoming slightly smaller and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 1–2xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2.5/2/7/3. P1 laminate; median carina sinuate in profile. P2 l/w ca. 2/1, sides parallel, apex blunt, raised slightly above mesoventral intercoxal process. Plaques moderately wide, straight, slightly converging toward one another anteriorly, weakly raised, located at sides of median depression. Metaventrite with very small point on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 1.5x P2. Protibia very slightly arcuate, medial margin slightly widened in distal 1/2. Meso- and metatibia slender, straight. Male abdominal apex slightly asymmetrical; last tergite with notch, offset to left side. Female (microslide mount, n=1) ( Fig. 160): last tergite broadly rounded, with deep apicomedian notch, ca. 16 hooked setae, apicomedian gap moderately wide; gonocoxite not midlongitudinally divided, apical margin sharply rounded, low transverse ridge evident at border of microreticulation; spermatheca type C2.

Etymology. Named in reference to the stridulatory head and scintilla ("squeak like a mouse").

Distribution. Currently known only from the type locality ( Fig. 195 ).

Figures

FIGURE 31. Hydraena mintrita, holotype, dorsal and lateral habitus, and venter.

FIGURE 36. Hydraena scintillarca, holotype, dorsal and lateral habitus, and venter.

FIGURE 195. Geographical distributions of Hydraena species in the Costiniceps Complex.