Merma antakotako, Szawaryn & Czerwiński, 2023

Szawaryn, Karol & Czerwiński, Tomasz, 2023, Three new species of Merma Weise (Coleoptera: Coccinellidae: Epilachnini) from Madagascar, Zootaxa 5306 (2), pp. 266-276 : 270-271

Merma antakotako sp. nov.

Figs 1D–F , 3 , 4

urn:lsid:zoobank.org:act:75776EBF-DE80-4BC5-ADC2-DBA5F8FDA779

Diagnosis. Coloration of M. antakotako sp. nov. is identical to all other Malagasy species of the genus Merma . From M. hovana and M. quadriguttata it can be easily separated by its larger body size, tarsal claws with additional subquadrate basal tooth and emarginate apex of ventrite 5 in male (ventrite 5 in males of M hovana and M. quadriguttata have arcuate apex). Merma antakotako sp. nov. has distinctly explanate lateral elytral margins, while in M. ankarana sp. nov. and M. fisheri sp. nov. it is narrowly explanate. With M. ankarana sp. nov. it shares emarginate posterior margin of ventrite 5 in male, while in M. fisheri sp. nov. it is rounded. The most reliable character to separate that species are structures of the male genitalia: penis guide in lateral view with inner margin almost straight/ slightly sinusoidal in middle, with small lateral thorn-like projections at level of 1/3 of its length ( Fig. 4B , arrow); tip of penis with broad, subtriangular lateral projection, and a single row of small denticles.

Etymology. Specific epithet is given after the Antakotako village where the paratype specimen was collected.

Description. Length 5.8–6.0 mm, width 5.0– 5.1 mm; length/width ratio = 1.16–1.17. Body ( Fig. 1D–F ) roundly oval, convex, dorsum pubescent. Head, mouthparts, legs and abdomen reddish-orange. Pronotum dark brown with anterior corners and lateral margins pale orange. Elytra dark brown, with two orange or reddish maculae on each elytron, anterior macula placed below humeral callus, posterior macula in apical part of elytron.

Head transverse, partially concealed in prothorax. Interocular distance about 0.6 times of head width. Inner eye orbits slightly emarginate antero-medially, closest in the middle. Antenna ( Fig. 3B ) composed of 11 antennomeres, about as long as 0.6 head width; scape large, elongate, slightly swollen; pedicel distinctly narrower than scape, elongate; antennomere 3 elongate, 1.3 times longer than pedicel; antennomeres 4–7 elongate, about 1.5 times as long as its width; antennomere 8 as long as wide; antennomeres 9–11 forming a distinct asymmetrical club. Ventral antennal ( Fig. 3C ) grooves distinct in anterior part, moderately long and straight, along inner margin of eye. Clypeus short, parallel-sided, its anterior margin emarginate, smooth without groove. Labrum transverse, short, anterior margin slightly emarginate, membranous. Prothorax. Hypomeron smooth, simply / finely punctate. Prosternal process ( Fig. 3E ) smooth, without carinae, bordered laterally. Prosternum in front of coxa about as long as coxal longitudinal diameter; anterior margin, uniformly arcuate, bordered; posterior margin with bordering line starting from the base of prosternal process, laterally reaching notosternal suture. Surface of prosternum covered with sparse small punctae.

Pterothorax.Mesoventral process covered with small tubercles along lateral margins, about as wide as mesocoxal diameter; meso-metaventral suture straight. Elytra with punctate of two sizes; lateral margins distinctly explanate, entirely visible from above. Epipleuron complete ( Fig. 3A ), broad, with distinct depressions to accommodate mid and hind legs in repose, inner margin with broad bordering line present in median and apical part. Mesoventrite covered with sparse and small punctures, with just a few larger in median part. Metaventral postcoxal lines ( Fig. 3E ) joined on metaventral process forming straight line, recurved and then descending laterally.

Legs ( Fig. 3A ) short and stout with apices of mid and hind femora not protruding from outer margin of elytral epipleuron. Trochanters angulately produced, with bordering line on their outer surfaces, and cavities on their inner surfaces for receiving tip of tibiae in repose. Protibiae slightly widened, all tibiae on outer edge with oblique carina near apex ( Fig. 3D ), without distinct apical spurs. Tarsal claws ( Fig. 3D ) double with additional subquadrate basal tooth, empodium absent.

Abdomen with five ventrites with ventrite 5 emarginate posteriorly ( Fig. 4A ). Abdominal postcoxal lines descending, sub-parallel to posterior margin of ventrite 1. Apical margin of tergite VIII rounded ( Fig. 4D ) and sternite VIII straight ( Fig. 4E ); apodeme of sternum IX ( Fig. 4F ) rod-like. Tergite X transverse, truncate apically ( Fig 4F ).

Male genitalia ( Fig. 4B, C, G–I ). Tegminal basal piece with a pair of indistinct spines near base of tegminal strut. Penis guide slightly asymmetrical in inner view ( Fig. 4C ), as long as parameres, distal ¼ of his length strongly tapering into apex; in lateral view ( Fig. 4B ) outer edge straight with curved tip and with densely setose field in the median part, inner edge weakly sinuate; in inner view with a pair of small thorns laterally. Parameres well developed, rounded apically. Tegminal strut distinctly shorter than penis guide, stout, strongly expanded distally. Penis ( Fig. 4I ) rod-like, sinuate; penis tip ( Fig. 4H ) asymmetrical, apex in inner view ( Fig. 4G ) with wide thorn-like projection on one side and with row of denticles on the other side; penis capsule with arms weakly developed.

Distribution. Madagascar ( Fig. 6 ).

Type material. Holotype: male, “ Madagascar, Baie d’Antongil , Voloina, X.1970, A. Villier rec” ( MNHN).

Paratype: male, “ Madagascar, Ron Maroantsetra , 11.39, Vadon / Antakotako ” (1, MNHN) .

Figures

FIGURE 1. Habitus of Merma species. A–C) M. ankarana sp. nov., male, holotype (MNHN); A) dorsal; B) lateral; C) frontal; D–F) M. antakotako sp. nov., male, paratype (MNHN); D) dorsal; E) lateral; F) frontal; G–I) M. fisheri sp. nov., male, holotype (CAS); G) dorsal; H) lateral; I) frontal.

FIGURE 3. Merma antakotako sp. nov., male, paratype (MNHN): A) habitus, ventral; B) antenna; C) mouthparts; D) apex of hind tibia and tarsus; E) pro-, meso- and metathotax, ventral view.

FIGURE 4. Merma antakotako sp. nov., male, holotype (MNHN): A) abdomen; B) tegmen, lateral; C) tegmen, inner; D) tergite VIII; E) sternite VIII; F) abdominal segments IX and X; G) penis tip, inner; H) penis tip, lateral; I) penis, lateral.

FIGURE 6. Distribution map of Merma.