Macrelmis germaini ( Grouvelle, 1896 )

Monte, Cinzia & Mascagni, Alessandro, 2016, Redescriptions and lectotype designations for two neotropical Elminae (Coleoptera: Elmidae), Zootaxa 4175 (2), pp. 167-179 : 168-173

Macrelmis germaini ( Grouvelle, 1896)

( Figs 1–7)

Cylloepus germaini Grouvelle 1896: 43 ; Zaitzev 1908: 298; Zaitzev 1910: 21.

Elsianus germaini Hinton 1936: 56 ; Hinton 1940: 393; Blackwelder 1944: 271; Hinton 1945a: 92; Moroni, 1985: 172. Macrelmis germaini Brown, 1984: 125 ; Elgueta & Arriagada 1989: 16; Manzo 2003: 170, 174; Manzo & Moya 2010: 137; Monte & Mascagni 2012: 21, 22; Segura et al. 2013: 27; Passos et al. 2015: 196, 205; Jäch et al. 2016: 118.

Status: Lectotype male herewith designated, housed in MNHN. The lectotype bears the following labels ( Fig. 1): “ Yungas [the next word illegible] / Cochabamba / Bolivia [h], [w]”, “ ♂ [p]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]”.

Condition: The lectotype is slightly damaged: last seven articles of right antenna and last three tarsomeres of both left and right legs are missing.

Diagnosis. Pronotal surface densely punctuate in anterior half, densely granulate in posterior half; meso-tibiae strongly arcuate near base, then straight until tip.

Redescription. Macrelmis germaini ( Grouvelle, 1896) . Lectotype: male ( Figs 2–7 ). BL: 5.3 mm, PL: 1.6 mm, PW: 1.8 mm, EL: 3.7 mm, EW: 2.0 mm, ID: 0.65 mm. Males size range (n = 3): BL: 4.59‒4.75 mm, PL: 1.39‒1.45 mm, PW: 1.6‒1.62 mm, EL: 3.2‒3.3 mm, EW: 1.8‒1.85 mm, ID: 0.55‒0.6. Female size range (n = 4): BL: 4.92‒ 4.70 mm, PL: 1.35‒1.41 mm, PW: 1.68‒1.75 mm, EL: 3.35‒3.51 mm, EW: 1.9‒2.0 mm, ID: 0.5‒0.6.

Body form elongate, subparallel. General color black with mouth-parts, antennae, tibiae and tarsi reddish brown; cuticle glossy.

Head. Partly retracted into prothorax, without distinct impressions. Surface densely granulate with oblong granules, area between granules with fine and sparse golden setae. Eyes protruding laterally. Antennae 11- segmented, filiform; first two segments thicker than remaining ones; segments 6‒10 with setae on distal lateral margin; apical segments long with cluster of apical setae. Labrum short, surface glossy, anterolateral margins with some golden setae. Clypeus with frontoclypeal suture distinct and straight; surface granulate like frons, with fine, sparse golden setae.

Thorax. Pronotum ( Fig. 4) feebly wider than long; anterior margin broadly convex; lateral margins finely granulate in anterior half, with anterior angles acute, posterior ones almost right-angled; base tri-sinuate. Sublateral carinae distinct over whole length, yet not very elevated, feebly sinuate. Discal area with superficial, median depression in front of round gibbosity situated in posterior half near the base, and two weak, round depressions situated at side of median depression, reaching almost mid-pronotum; gibbosity moderately elevated, with surface granulate. Surface densely punctuate in anterior half, with the punctuations increasing in size towards posterior margin, densely granulate with rounded, coarse granules along inner margin of sublateral carinae and in posterior half around gibbosity. Elytra more than twice as long as pronotum; anterior margin convex; humeral angles broadly rounded and strongly elevated; elytral apices very strongly protruding, apices together forming a feebly angulated V-shape structure. Each elytron with sub-parallel striae, formed by row of coarse, well separated punctures; accessory stria with 1/5 elytral length ( Fig. 2 ). Intervals slightly convex at base, flat towards apex except as follows: 2nd interval more convex basally; 3rd interval moderately convex from base to apex, more convex at base; 5th interval less convex than the third, but distally slightly carinate; 7th interval strongly elevated at base and slightly carinate distally. Intervals granulate as posterior half of pronotum and with fine, sparse and short hairs. Each elytron laterally on declivity before apex with weak, short, broad depression. Scutellum almost round, slightly convex; surface granulate as adjacent elytral intervals. Prosternum ( Fig. 3 ) distinctly produced anteriorly, sublateral carinae nearly complete, surface with minute dense granules; prosternal process slightly longer than wide, slightly depressed with margins feebly elevated between coxae, apex largely acute; surface with dense, coarse, oblong granules. Mesoventrite ( Fig. 3 ) deeply grooved medially for reception of prosternal process; narrower anteriorly, largely rounded on posterior margin. Metaventrite ( Fig. 3 ) with medial groove, deeper and large at its posterior edge. Disc and sides of metaventrite with coarse, dense, oblong granules diminishing in size towards sides and with very short golden setae between them. Legs thin, covered with dense, oblong granules. Pro-, meso- and metatibiae with single lateral fringe of tomentum extending from near base to near the tip. Protibiae thin and straight; mesotibiae strongly arcuate almost base, then straight until tip ( Fig. 5); metatibiae slightly curved almost base, then straight until the tip; near base 4–5 strong, irregular teeth with blunt apex along latero-ventral margin.

Abdomen ( Fig. 3 ). First ventrite with admedian carinae originating near hind coxae from lateral margins of intercoxal process and reaching the posterior margin of ventrite, low anteriorly, elevated to posterior margin of ventrite. Between admedian carinae and lateral margins raised of intercoxal process, an area plane, glossy with coarse, oblong granules on anterior half, glossy and smooth with few fine golden setae posteriorly; surface with coarse, oblong granules diminishing in size from admedian carinae edges towards ventrite sides. Ventrite II with oblong granules denser at sides, medial area smooth and glossy with few fine golden setae. Ventrite III similar to II, but smooth and glossy only on anterior margin of disc. Ventrites IV‒V like III, without smooth and glossy areas and with lateral margins produced posterolaterally.

Genitalia. Length: 1.8 mm. Parameres slightly shorter of aedeagus and slightly compressed dorsoventrally. Parameres in dorsal view ( Fig. 6 ) wide, narrower in the middle, with their basalmost inner angles rounded as well as their inner margin a little before apex; in lateral view ( Fig. 7 ) narrower towards apex. Aedeagus in dorsal view ( Fig. 6 ) tapering towards apex, sides almost straight, apex slightly blunt; in lateral view ( Fig. 7 ) almost straight, dorsally distinctly convex at base, less so at apex. Phallobase ( Figs 6, 7 ) slightly longer than parameres; in dorsal view broad, asymmetrical, in lateral view narrow, slightly constricted at about mid-length.

Female. All external morphological characters as in male, except for mesotibiae and metatibiae feebly curved near base, for absence of teeth on inner side of metatibiae and for admedian carinae not elevated to posterior margin of ventrite I.

Intraspecific variation. The specimens examined show no significant morphological variability.

Comparative notes. In a recent paper, Passos et al. (2015) proposed a new species groups definition for the Macrelmis genus, in which all six known species groups are redefined and rearranged and four new ones are proposed, for a total of ten species groups, based mainly on the morphology of the male genitalia. In the present work, we follow their new species group definition. According to the new definition of the granigera species group Hinton, 1940, M. germaini , until now a member of this group ( Hinton 1945a), cannot be included in this latter group for the different shape of male genitalia: it has neither aedeagus with truncated apex, nor a constriction two thirds before the apex. After a careful examination of the shape and size of parameres and aedeagus, we finalize that M. germaini cannot be placed in any of the ten groups of species (see “Diagnostic character” for each group in Passos et al. 2015). Moreover, M. germaini differs from M. bispo Barbosa et al., 2013 , M. immsi ( Hinton, 1936) and M. saltensis Manzo, 2003 (all species not assigned to any group by Passos et al. 2015) by its aedeagal morphology: M. bispo has parameres shorter than aedeagus with rounded apex; M. immsi has a very broad aedeagus longer than parameres; M. saltensis has parameres distincty shorter than aedeagus with lateral setae on apical half. Within the species without male genitalia known, M. germaini differs from M. aequalis (Hinton, 1937) , M. pubescens ( Grouvelle, 1889) and M. bicolor (Hinton, 1939) by presence of pronotal sublateral carinae; from M. robusta (Sharp, 1882) by pronotum with punctures and granules; from M. antiqua ( Grouvelle, 1896) , M. granosa ( Grouvelle, 1896) and M. peruviana (Hinton, 1945) by pronotum with sublateral carinae extending from base to almost apex, not extending to the anterior fifth of sides as in M. granosa and M. peruviana or very short as in M. antiqua . Finally we don’t make any comparison with M. coquereli ( Grouvelle, 1889) , M. dentata Motschulsky, 1859 , M. moesta (Horn, 1870) and M. texana (Schaeffer, 1911) , lacking illustrations and adequate descriptions. As M. germaini has an unusual shape of male genitalia it should be considered as belonging in its own group. Its aedeagus tapers towards the apex and is slightly shorter than the parameres ( Figs. 6, 7 ). The latter, in dorsal view, are wide, narrower in the middle, with their basalmost inner angles rounded as well as their inner margin a little before apex ( Fig 6 ). Also, we include Macrelmis elicioi Monte & Mascagni, 2012 , whose genitalia are similar to those of M. germaini , in the germaini species-group, although M. elicioi was originally assigned to the graniger species-group by Monte & Mascagni (2012). Unfortunately, Passos et al. (2015) did not mention M. elicioi .

Type series. Macrelmis germaini (Grouvelle) : Lectotype: see above. Paralectotypes: 1 ♂, “ Yungas [the next word illegible] / Cochabam. / Bolivia [h], [w]”, “ ♂ [p]”, “ Prépar. genit. / N° 22666.11, [p, h], [reddish label], [the genitalia are missing]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]” ; 1 ♂, “ Yungas [the next word illegible] /, Cochabamb. / Bolivia ”, “ ♂ [p]”, “ Prépar. genit. / N° / 17367.1 [p, h], [reddish label], [the genitalia are missing]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]”, “exam. / et dess. [h]” ; 1 ♂, “ Cochabamba / Bolivia [h], [blue label]”, “ ♂ [p]”, “ Prépar. genit. / N° 22666.8 [p, h], [reddish label], [the genitalia are missing]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]” ; 1 ♀, “ Cochabamba / Bolivia [h], [yellowish label]”, “ ♀ [p]”, “ J. Delève det, 1966 / Elsianus / germaini Gr. [p, h], [w]” ; 1 ♀, “ Cochabamba / Bolivia [h], [yellowish label]”, “ ♀ [p]”, “ J. Delève det, 1966 / Elsianus / germaini Gr. [p, h], [w]” ; 1 ♀, “ Cochabamba / Bolivia [h], [yellowish label]”, “ ♀ [p]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]” ; 1 ♀, “ Cochabamba / Bolivia [h]”, “ ♀ [p]”, “ Cylloepus / germaini Grouv. [h]”, “ J. Delève det., 1966 / Elsianus / germaini Gr. [p, h], [w]”.

Remarks. Grouvelle (1896) did not mention the number of specimens and their sex in the original description of Cylloepus germaini from “ Bolivie: Province de Cochabamba ”. The type series of Macrelmis germaini we could see consists of 8 specimens, 4 males and 4 females, all slightly damaged ; 3 males are without genitalia.

Figures

FIGURE 2. Lectotype male of Macrelmis germaini: habitus, dorsal view. Scale bar: 1 mm.

FIGURE 3. Lectotype male of Macrelmis germaini: habitus, ventral view. Scale bar: 1 mm.

FIGURES 6 – 7. Lectotype male of Macrelmis germaini: 6) male genitalia, dorsal view; 7) male genitalia, lateral view. Scale bar: 0.5 mm.