Macrelmis froehlichi, Barbosa, Felipe Francisco, Fernandes, André Silva & Oliveira, Leandro Gonçalves, 2013

Barbosa, Felipe Francisco, Fernandes, André Silva & Oliveira, Leandro Gonçalves, 2013, Three new species of Macrelmis Motschulsky, 1859 (Coleoptera: Elmidae: Elminae) from the Brazilian Cerrado Biome with updated key for the Macrelmis of Brazil, Zootaxa 3736 (2), pp. 128-142 : 132-135

Macrelmis froehlichi sp. nov.

( Figs 6–9 )

Diagnosis. 1) body sub-parallel, elongate ( Figs 6, 7 ); 2) pronotum equally wider (1.11 mm) than long (1.11 mm); 3) pronotum with median longitudinal impression evident, extending from apical 1/2 to middle; 4) pronotum with sublateral carinae extending along almost entire length, but not reaching base nor anterior margin; 5) elytral apex indehiscent, moderately produced and truncate; 6) elytra with lateral margins sub-parallel from base to apical 1/3.

Description. Holotype: male. Length 3.66 mm, maximum width 1.22 mm (across apical 1/4 of elytra), pronotal length 1.11 mm, elytral length 2.55 mm. Body sub-parallel, elongate.

Color: cuticle black to dark gray, except for: tarsal claws, tarsomeres, antennae, last segment of maxillary palpus and last segment of labial palpus which are light brown; trochanters dark brown.

Head: without distinct impressions. Eyes slightly protuberant, laterally rounded separated by twice the diameter of eye. Antenna 11-segmented, filiform; last segment elongate with subtriangular apex, about as long as first two segments combined, and approximately 1.5 times as long as each of the segments 3–10. Labrum subrectangular, with fine golden setae. Clypeus sub-rectangular, covered with fine golden setae. Frontoclypeal suture distinct. Frons granulate. Maxillary palpus with last segment flattened, longer than remaining segments combined. Labial palpus with last segment rounded, longer than remaining segments combined.

Thorax ( Figs 6, 7 ): Pronotum equally wider (1.11 mm) than long (1.11 mm); scarcely granulate; covered with fine golden setae; median longitudinal impression shallow and evident, from near the base to apical 1/3; sublateral carinae extending along almost entire length, but not reaching base nor anterior margin; anterior angles very produced and sharp; anterior margin broadly rounded and finely crenate, slightly produced over head; lateral margin crenate. Hypomeron granulate. Elytra 2.55mm long, 1.22mm wide; granulate; lateral margin crenate, subparallel on basal two thirds, then converging strongly to apex; humeral angle broadly rounded and entumed; without carinae; accessory stria with 1/5 the length of elytra; apex indehiscent, moderately produced and truncate. Epipleura granulate. Scutellum feebly convex, longer (0.22 mm) than wide (0.11 mm); with rounded angles; oval to sub-pentagonal; with large punctures, 1/5 times the length of scutellum itself. Prosternum wider (0.94 mm) than long (0.88 mm), granulate, with anterior margin truncate; with moderate median transversal depression. Prosternal process 1.5 times longer (0.66 mm) than wide (0.44 mm), widest at base, granulate, extending beyond front coxae; apical and lateral margins smooth, with discrete preapical constriction; apex rounded. Mesoventrite between coxae wider (0.88 mm) than long (0.33 mm); with deep median groove for reception of prosternal process; lateral margin of mesoventrite elevated and granulate. Metaventrite three times as long as mesoventrite, densely granulate; inconspicuous median groove extending from near posterior to near anterior margin. Legs thin and straight, granulate. Tibiae with apical fringes of tomentum, front tibiae with one anterior fringe extending from apical 2/3 almost to apex; middle tibiae with two fringes, one anterior, a very fine band before apex, and one posterior, extending from apical 2/3 almost to apex; hind tibiae with one posterior fringe, extending from apical 2/3 almost to apex. Broadly dilated Spur at the apex of hind tibia broadly. Middle and hind trochanter slightly entumed.

Abdomen ( Figs 6, 7 ): length 1.3 mm, width 1.25 mm (along ventrite I). Middle region of ventrite I coarse and densely granulate; middle region of ventrites II, III, IV and V punctuate. Lateral region of all ventrites densely granulate. Ventrite V with posterolateral projections extending to about same line as posterior 3/4 of ventrite; apex rounded with moderately short setae.

Genitalia ( Figs 8, 9 ): parameres, in dorsal view, elongate, gradually tapering from base to apex, almost reaching the same line as penis apex, apex acute. Penis, in dorsal view, elongate, gradually tapering from base to apex, at least twice wider than parameres, apex nearly acute. Phallobasis, in dorsal view, tapering gradually from apex to base, with almost the same length as penis, approximately 1.5 times longer than broad, base diagonally excavated at right side; in lateral view, sub-parallel and elongated.

Plastron ( Figs 6, 7 ): gold-silver, present on gena, proepisternum, proepimeron, hypomeron, mesoepisternum, mesoepimeron, lateral sides of prosternum, metaepisternum, lateral sides of metaventrite, lateral sides of front and hind coxae, ventral region of femora, trochanters, epipleura. Plastron present on ventrites, except for a triangular area on anterior 1/2 of ventrite V.

Female: Externally similar to male.

Intraspecific variation. Size variation (N = 10): length 3.3–4.8 mm. Some specimens present median longitudinal shallow impression, evident on apical 1/3.

Type locality. BRAZIL: Goiás (GO): Pirenópolis, 15°51'43''S, 49°11'41,2''W.

Type series. Holotype: 1 male, Pirenópolis, GO, 15°51'43''S, 49°11'41.2''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), litter submerged (CELAMARH). Paratype: 1 female, same data as holotype (CELAMARH); 1 female, São Francisco de Goiás, GO, 15°52'52.9''S, 49°16'7.2''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), rocks (CELAMARH); 1 ex., São Francisco de Goiás, GO, 15°58'53.9''S, 49°11'11.4''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), rocks (CELAMARH); 2 exs., Morro Agudo de Goiás, GO, 15°21'45''S, 49°58'11.9''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), litter submerged (CELAMARH); 1 male, same data as holotype, (MZUSP); 3 exs., same data as holotype, (MZUSP); 1 female, Rio Verde, GO, 17°58’39.78''S, 51°0’0''W, A. S. Fernandes, F. F. Barbosa, L. F. R. Holanda,?/ IV/2010, aquatic sampling nets (2,0 mm mesh), litter submerged (MZUSP).

Habitat note. The species was collected in streams of first and second order, inhabiting micro-habitats formed by rocks (8 specimens) and submerged litter (4 specimens).

Etymology. The specific epithet froehlichi is in honor to Dr. Claudio Gilberto Froehlich (Universidade de São Paulo; Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto; Ribeirão Preto–SP, Brazil) in recognition for his contributions to the study of aquatic insects of Brazil.

Distribution. The species is known only from Goiás State (GO).

Figures

FIGURES 6 – 9. Macrelmis froehlichi sp. nov. (male Holotypus): 6) habitus, dorsal view; 7) habitus, ventral view; 8) male genitalia, dorsal view; 9) male genitalia, lateral view. Scale: 1.0 mm (2, 3), 100 µm (4, 5).