Acroleptina Bocakova, 2005

Ferreira, Vinicius S., 2020, Revision of Acroleptus Bourgeois, 1886 and descriptions of New Acroleptina taxa (Coleoptera, Lycidae, Calopterini), Journal of Natural History (J. Nat. Hist.) 53 (45 - 46), pp. 2739-2756 : 2740-2746

Subtribe Acroleptina Bocakova, 2005

Genus Acroleptus Bourgeois, 1886

Figures 1 – 18, 25.

Acroleptus Bourgeois, 1886 : LXX; Kleine 1933: 34; Blackwelder 1945: 348; Bocakova 2003: 215, 231, Bocakova 2005: 445; Bocak and Bocakova 2008: 713; Ferreira 2015: 297.

Acroleptus ; Cabanis 1861: 90; Gray 1870:78; McGregor 1920:8; Hellmayr 1936: 14 (see remark below).

Type species. Acroleptus chevrolati Bourgeois, 1886 (by monotypy).

Differential diagnosis. Acroleptus can be distinguished from other Calopterini by the combination of pronotum with a strongly visible longitudinal cell ( Figures 1, 4, 7) (vs. absence or weakly developed cell in Aporrhipis ), flabellate antennae with flabellum of antennomere III subequal in length with the stem ( Figures 10, 11) (vs. serrate or subserrate in most genera, except Aporrhipis ), frons concave and elongate ( Figures 3, 6, 9) (vs. transverse frons in Aporrhipis ), elytra with four costae, easily visible and reticulate ( Figures 1, 4, 7) (vs. costae indistinct and incomplete with weak reticulation in Aporrhipis ), non-reduced mouthparts and male genitalia with the presence of folds in the basal inner margin of median lobe ( Figures 16 – 18).

Description. General dorsal colouration dark brown, with pronotum dark brown or orange ( Figures 1, 4, 7). Body setose, dorsal pubescence long and erect on elytra, remainder of body with fine yellowish pubescence throughout ( Figures 1 – 9).

Body. Head: as long as wide, widest behind eyes, posteriorly partially covered by pronotum, hypognathous, frons concave and elongate, acuminate at apex ( Figures 3, 6, 9). Eyes hemispherical, projecting anterolaterally when viewed dorsally; coarsely granulate. Mouthparts: Maxillary palp four-segmented, with last palpomere acuminate, setose. Labial palp 3-segmented, terminal segment, acuminate, setose. Mandibles strongly hooked apically. Posterior margin of epistoma emarginate, labrum transverse, setose. Antennae: inserted in gibbous prominence at anterior portion of head, 11- segmented ( Figures 10, 11), reaching middle of elytra or apex, densely setose; scape subconic, pedicel short, flagellomeres III – X flabellate on outer portion; flabellum of antennomere III subequal in length with the stem ( Figures 10, 11).

Prothorax: Pronotum transverse, trapezoidal; margins prominent; anterior angles round, posterior angles moderately acute; longitudinal carina present in anterior portion, bifurcated medially forming a cell ( Figures 1, 4, 7). Hypomeron concave, when viewed laterally, basal margin ranging from emarginate to marginate. Prosternum Y-shaped, tripartite, connected to hypomeron by additional segment ( Figure 12). Mesothorax: Mesoespiracles short, slightly protuberant ( Figure 12). Mesoventrite trapezoidal, posteriorly reaching anterior margin of metaventrite, connected to mesanepisternum by additional segment, mesepimeron more densely pubescent than surrounding sclerites ( Figure 12). Scutellum protruded, posteriorly bifurcated. Metathorax: Metaventrite convex, posterolateral angles pronounced, acute; metadiscrimen complete; metanepisternum and metepimeron elongate, widest in the middle, metendosternite (as represented by Acroleptus alvarengai ) elongate, membranous, with strongly visible ventral longitudinal flange, furcal arms short and not protrudent ( Figure 14). Elytra: subparallel, ranging from 7 to 8× longer than pronotum; reticulate, with four elytral costae more or less developed on each elytron, secondary costae absent ( Figures 1, 4, 7). Legs: slender, elongate; Protrochanthin slender and exposed ( Figure 12); trochanters tubular; femora and tibiae quite elongate, ranging from clavate to subparallel, subequal in length ( Figure 13); Pro- and mesocoxae conical, obliquely positioned, procoxae contiguous, metacoxae transverse ( Figure 12); tarsomeres 5-5-5, very narrow, tarsomere four not expanded laterally ( Figure 13).

Abdomen of males with eight ventrites, tapered towards apex, densely setose ( Figure 15); male genitalia symmetrical; median lobe ranging from twice to 2/3 the length of parameres,

slightly tapered towards apex, rounded apically, with the presence of folds in the basal inner margin of median lobe ( Figures 16 – 18); parameres rounded apically; phallobase elongate, lateral margins subparallel, posterior margin rounded or irregular ( Figures 16 – 18).

Females unknown.

Length (pronotum+elytra): 4.6 – 5.2 mm. Width (across humerus): 1.1 – 1.4 mm.

Distribution. Acroleptus is known only to occur in Brazil but expected to be found in other surrounding South American countries ( Figure 25).

Biology and immature. Females are unknown and presumably neotenic (see discussion section). As for many other Neotropical lycids, information about the ecology and biology of Acroleptus is unknown.

Remark. See Ferreira (2015) for a discussion on the validity of Acroleptus Bourgeois, 1886 (Insecta) over Acroleptus Cabanis, 1861 (Aves) , the latter being an incorrect subsequent spelling.

Key to the species of Acroleptus

1. Pronotum unicoloured, orange ( Figure 7); folds in the basal inner margin of median lobe strongly developed ( Figure 18). .................................. Acroleptus limai new species

1 ʹ. Pronotum bicoloured, either with margins or disc region orange or yellow ( Figures 1, 4) genitalia variable ..................................................................................................................................... 2

2. Pronotum orange, disc region dark brown ( Figure 4); elytra completely dark brown ( Figure 4); median suture of phallobase absent ( Figure 17)...................................................... ................................................................................................. Acroleptus alvarengai new species

2 ʹ. Pronotum dark brown, lateral margins yellow ( Figure 1); humeral region of elytra yellow ( Figure 1); median suture of phallobase present ( Figure 16)...................................... ......................................................................................... Acroleptus chevrolati Bourgeois, 1887