Macrelmis nessimiani, 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 : 135-139

Macrelmis nessimiani sp. nov.

( Figs 10 – 13 )

Diagnosis. 1) body sub-parallel, robust ( Figs 10, 11 ); 2) pronotum wider (1.42 mm) than long (1.28 mm); 3) pronotum without carinae or impressions; 4) elytra with seventh interval carinate at apex; 5) elytral apex truncate to broadly rounded; 6) scutellum protruding.

Description. Holotype: male. Length 4.04 mm, maximum width 1.57 mm (across apical 1/4 of elytra), pronotal length 1.28 mm, elytral length 2.76 mm. Body sub-parallel, robust.

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

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

Thorax ( Figs 10, 11 ): Pronotum wider (1.42 mm) than long (1.28 mm); sparsely granulate; with silver-golden setae; without carinae or impressions; anterior angles produced and sharp; anterior margin finely crenate, slightly produced over head; lateral margin crenate. Hypomeron granulate. Elytra 2.76mm long, 1.57mm wide; granulate; lateral margin sub-parallel on basal 2/3, then converging strongly to apex; lateral margin crenate; humeral angle broadly rounded and entumed; without carinae or impressions; accessory stria with 1/5 the length of elytra; apex truncate and not projected. Epipleura granulate. Scutellum strongly convex, with anterior angles acute and posterior angles rounded, longer (0.24 mm) than wide (0.18 mm), oval to ellipsoid; protruding; with few punctures, punctures with the diameter of facets. Prosternum wider (1.04 mm) than long (0.95 mm), granulate, with anterior margin truncate; without impressions or carinae; with moderate median transversal depression. Prosternal process 1.5 times longer (0.90 mm) than wide (0.57 mm), widest at base, densely granulate, extending beyond front coxae; apical and lateral margins feebly elevated and smooth, with distinct preapical constriction; apex rounded to subtriangular. Mesoventrite between coxae wider (0.95 mm) than long (0.32 mm); with deep median groove for reception of prosternal process; lateral margin of mesoventrite elevated, granulate and distinctly projected posteriorly, surrounding internal margin of mesocoxal cavity. Metaventrite three times as long as mesoventrite, densely granulate; median groove extending from near posterior to near anterior margin. Legs thin and straight, granulate; Tibiae with apical fringes of tomentum, front tibiae with anterior fringe extending from apical 2/3 almost to apex; middle tibiae with two fringes, one anterior, extending from middle almost to 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. Middle and hind trochanter entumed.

Abdomen ( Figs 10, 11 ): length 1.7 mm, width 1.7 mm (along ventrite I). Ventrites densely and finely granulate except: anteromedial 2/3 of ventrite I, coarse and densely granulate; posteromedial 1/3 of ventrite I; middle of ventrite II and basal 1/3 of ventrite III punctuate; triangular anteromedial region and posterior region of ventrite V. Ventrite V with posterolateral projections very produced, extending to about same line of the posterior margin of the ventrite; apex rounded with moderately short setae.

Genitalia ( Figs 12, 13 ): parameres, in dorsal, view, gradually tapering from base to basal 1/2, at this point the width decreases abruptly, extending until apical 4/5 of penis, apex rounded. Penis, in dorsal view, sub-parallel, as wide as base of parameres, apex truncate to broadly rounded. Phallobasis, in dorsal view, sub-parallel, with nearly the same length as penis, 1.5 times as long as broad, base diagonally excavated at left side; in lateral view, strongly bent ventrally.

Plastron ( Figs 10, 11 ): gold-silver, present on gena, proepisternum, proepimeron, antero-lateral area of prosternum, hypomeron, mesoepisternum, mesoepimeron, lateral sides of prosternum, metaepisternum, lateral sides of metaventrite, lateral side of hind coxae, whole femora (except apices), epipleura. Plastron present on ventrites, except disc of ventrite I and median narrow in ventrite II.

Female. Externally similar to male.

Intraspecific variation. Size variation (N = 9): length 4.0– 4.7 mm. The specimens examined showed no significant morphological variation. Apex of last segment of maxillary palpus and apex of last segment of labial palpus varies between light brown to dark brown.

Type locality. BRAZIL: Goiás (GO): Jaraguá, 15°49'05,38''S, 49°19'28,67''W.

Type series. Holotype: 1 male, Jaraguá, GO, 15°49'5.4''S, 49°19'28.7''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), rocks (CELAMARH). Paratype: 1 ex., Itapuranga, GO, 15°29'20''S, 50°6'18.6''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), litter submerged (CELAMARH); 1 ex., Jaraguá, GO, 15°48'16.7''S, 49°21'18.6''W, B. S. Godoy,?/VIII-X/2008, aquatic sampling nets (2,0 mm mesh), rocks (CELAMARH); 1 ex., same data as holotype (CELAMARH); 1 male, same data as holotype (CELAMARH); 1 male, same data as holotype (MZUSP); 4 exs., same data as holotype (MZUSP).

Habitat note. Macrelmis nessimiani sp. nov. were collected only in micro-habitats formed by rocks. All samples were collected in the streams of the first and second order.

Etymology. The specific epithet nessimiani (the surname “ Nessimian ”, declined in the Latin dative mode) is in honor to Dr. Jorge Luiz Nessimian (Universidade Federal do Rio de Janeiro; Instituto de Biologia; Departamento de Zoologia; Rio de Janeiro–RJ, 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 10 – 13. Macrelmis nessimiani sp. nov. (male Paratypus): 10) habitus, dorsal view; 11) habitus, ventral view; 12) male genitalia, dorsal view; 13) male genitalia, lateral view. Scale: 1.0 mm (2, 3), 100 µm (4, 5).