Merma fisheri, 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 : 272-275

Merma fisheri sp. nov.

Figs 1G–I , 5

urn:lsid:zoobank.org:act:8522CA47-C497-4C39-B947-8B0D77A3D26C

Diagnosis. Coloration of M. fisheri 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 and tarsal claws with additional subquadrate basal tooth. Merma fisheri sp. nov. has narrowly explanate but visible lateral elytral margins similar to M. ankarana sp. nov., while in M. antakotako sp. nov. lateral elytral margins are distinctly explanate. Moreover males have broadly rounded apical margin of ventrite 5 while in M. antakotako sp. nov. and M. ankarana sp. nov. it is emarginate. The most reliable character to separate that species are structures of the male genitalia: penis guide in lateral view with inner margin incised in middle; penis subparallel and broadened apically, with two rows of small denticles, without lateral projection.

Etymology. The new species is named after Bryan L. Fisher, leader of the CAS Madagascar project and one of the collectors of the type series.

Description. Length 5.1–6.2 mm, width 4.4–4.8 mm; length/width ratio = 1.17–1.20. Body ( Fig. 1G–I ) roundly oval, strongly convex, dorsum pubescent. Head, mouthparts, legs and abdomen reddish-orange. Pronotum chestnut brown with anterior corners and lateral margins pale orange. Elytra chestnut brown, with two dark yellow or orange 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 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 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 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 weakly explanate, clearly visible only in anterior half of its length from above. Epipleuron complete, 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 joined on metaventral process forming straight line, recurved and then descending laterally.

Legs 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, without distinct apical spurs. Tarsal claws double with additional subquadrate basal tooth, empodium absent.

Abdomen with five ventrites, with ventrite 5 rounded posteriorly in both sexes ( Fig. 5A, B ), in female ventrite 5 with transverse impression at base of ventrite. Abdominal postcoxal lines descending, sub-parallel to posterior margin of ventrite 1, recurved shortly laterally. In male apical margin of tergite VIII ( Fig. 5C ) and sternite VIII broadly rounded ( Fig. 5E ); apodeme of sternum IX ( Fig. 5M ) rod-like. Tergite X transverse, truncate apically ( Fig. 5M ). In female apical margin of tergite VIII rounded ( Fig. 5D ), sternite VIII ( Fig. 5F ) shallowly emarginate medially and with broad, sclerotised lobe anteriorly.

Male genitalia ( Fig. 5G–I, K, L ). Tegminal basal piece with a pair of indistinct spines near base of tegminal strut ( Fig. 5K , arrows); penis guide slightly asymmetrical in inner view, as long as parameres, distal 1/3 of his length strongly tapering into apex; in lateral view ( Fig. 5L ) outer edge straight with curved tip and with densely setose field in the median part, inner edge smooth. Parameres well developed, rounded apically. Tegminal strut distinctly shorter than penis guide, stout, expanded distally. Penis ( Fig. 5G ) rod-like, sinuate; penis tip ( Fig. 5H ) asymmetrical, flattened, in inner view broadened ( Fig. 5I ), with two rows of denticles; penis capsule with arms weakly developed.

Female genitalia ( Fig. 5J ). Coxites rectangular, setose. Styli well developed, elongate, with long apical setae. Bursa copulatrix at base partially sclerotised, simple, not divided, ending with common oviduct. Sperm duct short, originating in the middle of the bursa, dorsally on bursa. Spermatheca lightly sclerotized, simple, vermiform, accessory gland short, membranous.

Distribution. Madagascar ( Fig. 6 ).

Type material. Holotype: male, Madagascar, Forêt d'Orangea , 3.6 km 128° SE Remena, 22- 28.02.2001, lat. -12.25889 long. 49.37467, 90 m (a.s.l.), litoral rainforest, Malaise trap, B.L. Fisher, C.E. Griswold, Malagasy Arthropod Team, collection code BLF03199, CAS 3199 ( CAS) . Paratypes: Madagascar, Forêt de Bekaraoka , 6.8km 60° ENE Daraina, 07.12.2003, lat. -13.16667 long. 49.71, 150 m (a.s.l.), tropical dry forest, Malaise trap, B.L. Fisher, collection code BLF09874, CAS 9874 (1 female, CAS). N Madagascar, Mahamatsina env., Ankarana N.P., F. Pavel leg, 5- 6.01.2007 S 12°58’08.7’’ E 49°08’10.3’’ (1 male, 1 female, JVC) .

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 5. Merma fisheri sp. nov., A, C, E, G–I, K–M: male, holotype (CAS); B, D, F, J: female, paratype (CAS): A) abdomen, male; B) abdomen, female; C) tergite VIII, male; D) tergite VIII, female; E) sternite VIII, male; F) sternite VIII, female; G) penis, lateral; H) penis tip, lateral; I) penis tip, inner; J) female genitalia; K) tegmen, inner; L) tegmen, lateral; M) male abdominal segments IX and X.

FIGURE 6. Distribution map of Merma.