Merma quadriguttata ( Sicard, 1909 ) Szawaryn & Churata-Salcedo, 2022

Szawaryn, Karol & Churata-Salcedo, Julissa, 2022, Revision of Malagasy species of the genus Merma Weise (Coccinellidae: Epilachnini), Zootaxa 5087 (4), pp. 571-582 : 576-578

Merma quadriguttata ( Sicard, 1909) comb. nov.

Figs 4–6

Peralda quadriguttata Sicard, 1909: 114 . Type locality: Ambositra.

Diagnosis. Colouration of Merma quadriguttata is identical to M. hovana , however, its body is smaller and more elongate, with lateral elytral margin not visible from above, moreover, it has terminal labial palpomere elongate, parallel sided, hypomeron and prosternum covered with distinct large punctae, elytral epipleuron narrow, less than two times as broad as width of metanepisternum, median part of metaventrite covered with large punctae, abdominal postcoxal lines distinctly recurved laterally, and male genitalia lightly sclerotized with penis guide simple with grooves in apical part, and penis long, strongly sinuate with long apical flagellum. From the African species that also have four maculae on elytra it can be distinguished by distinctly smaller spots, while in African species they occupy at least half of elytral surface.

Description. Length 3.3 mm, width 2.6 mm. Body ( Figs 4A–C , 5A–C ) elongate oval, strongly convex, dorsum pubescent. Head, mouthparts, legs and abdomen reddish-orange. Pronotum chestnut brown with narrow reddish bordering of anterior pronotal margins. Elytra chestnut brown, with two orange or reddish maculae on each elytron, the first placed below humeral callus, the second in apical part of elytron.

Head transverse, partially concealed in prothorax. Interocular distance about 0.6 times of the head width. Inner eye orbits slightly emarginate antero-medially, closest in the middle. Antenna ( Fig. 6C ) 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, about as long as pedicel; antennomeres 4–5 elongate, about twice as long as its width; antennomeres 6–7 subquadrate; antennomere 8 slightly transverse; antennomeres 9–11 forming a distinct asymmetrical club. Ventral antennal grooves ( Fig. 6C ) 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 emarginate, membranous. Mandible multidentate apically. Maxilla ( Fig. 6B ) with cardo semicircular; with suture between basistipes and mediostipes well visible; lacinia simple, its mesal surface simply setose; galea oval, mostly sclerotized, its ventral surface sparsely pubescent, anterior surface covered with long setae and sensillae; terminal palpomere elongate, with sides subparallel. Submentum short, transverse, with suture well visible; mentum ( Fig. 6B ) transverse, widest at base; prementum transverse with anterior margin emarginae medially, ligula covered with moderately long setae; labial palps ( Fig. 6B ) separated by distance about half of width of palpiger; apical palpomere distinctly shorter and narrower than penultimate one.

Prothorax. Hypomeron covered with large punctae. Prosternal process ( Fig. 6C ) 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 base of prosternal process, laterally reaching notosternal suture. Surface of prosternum covered with large punctae.

Pterothorax. Mesoventrite ( Fig. 6D ) with anterior edge weakly emarginate, anterior margin entirely raised and bordered, with distinct foveae for receiving midlegs ( Fig. 6A ); mesoventral process about as wide as mesocoxal diameter, covered with small tubercles on entire surface ( Fig. 6D ); meso-metaventral suture straight. Scutellar shield triangular, about as long as broad. Elytra with two types of punctate; lateral margins not explanate, not visible from above. Epipleuron incomplete apically only ( Fig. 6A ), narrow, less than two times of width of metanepisternum, with distinct depressions to accommodate mid and hind legs in repose, inner margin with narrow bordering line complete. Mesoventrite covered with sparse and larger punctae in median part, with smaller punctae laterally. Metaventral postcoxal lines ( Fig. 6D ) joined on metaventral process forming straight line, recurved and complete laterally.

Legs ( Fig. 6A ) short and stout with apices of mid and hind femora not protruding from outer margin of elytral epipleuron. Trochanters subquadrate, 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. 6D ), without distinct apical spurs. Tarsi pseudotrimerous with tarsal claws ( Fig. 6E ) double, swollen at base, empodium absent.

Abdomen with five ventrites in both sexes with ventrite 5 arcuate posteriorly ( Figs 4E , 5D ). Abdominal postcoxal lines ( Fig. 4E , 5D ) rounded, recurved, not parallel to the posterior margin of ventrite 1. In male apical margin of sternite VIII truncate ( Fig. 5H ), tergite VIII rounded ( Fig. 5I ); apodeme of sternum IX ( Fig. 5J ) rod-like, narrow. Tergite X transverse, truncate apically ( Fig. 5J ). In female apical margin of sternite VIII rounded, simply arcuate at base, longitudinally at middle not divided; tergite VIII rounded ( Fig. 4F ). Proctiger (TX) large, transverse, truncate at apex, entire in middle.

Male genitalia ( Fig. 5E–G ). Tegminal basal piece without distinct spines on inner margin near base of tegminal strut. Penis guide symmetrical in inner view, as long as parameres, with apical third subtriangular in shape, pointed, entire at apex; in lateral view outer edge covered with distinct small tubercles each bearing long seta, inner edge with distinct groove before apex. Parameres well developed, simple apically. Tegminal strut about as long as the rest of tegmen, narrow, simple at apex. Penis rod-like, strongly sinuate in apical half, ending with translucent flagellum; penis capsule with weakly developed.

Female genitalia ( Fig. 4F ). Sclerite anterior to coxites in membrane connecting paraprocts absent. Coxites small, distinctly transverse, with inner edge rounded, ventral surface smooth. Styli well visible. Bursa copulatrix without additional sclerite, simple, not divided, ending with common oviduct.

Distribution. Madagascar ( Fig. 7 ).

Type material examined. Holotype: “Madagascar, Ambositra/ TYPE/ Peralda quadrigutata, L.A. Almeida det. 2017”, female ( MNHM) ( Fig. 4D ) . Other material. MADAGASCAR: Mahajanga, Parc National d’Ankarafantsika, Ampijoroa Station Forestière, 40 km 306° NW Andranofasika (-16.32083 46.81067), sample number BLF03524, 130 m a.s.l., 26.03- 01.04.2001, coll. B.L. Fisher; C.E. Griswold; Malagasy Arthropod Team, beating, tropical dry forest (1 male: CAS) .

Remarks. P. quadriguttata was originally described based on a single female specimen, the holotype that we examined. We also found a second specimen (male) that is identical externally, however, it comes from a different location more than 550 km north from the type locality. As there are no external differences in shape, colouration, size or other features we consider this specimen conspecific. Nonetheless, examination of further specimens from the type locality would confirm our hypothesis.

Figures

FIGURE 4. Merma quadriguttata (Sicard, 1909), holotype (MNHN), female: A—habitus, dorsal, B—habitus, frontal, C—habitus, lateral, D—holotype label data, E—abdomen, F—female genitalia.

FIGURE 5. Merma quadriguttata (Sicard, 1909), non type (CAS), male: A—habitus, frontal, B—habitus, lateral, C—habitus, dorsal, D—abdomen, male, E—penis, lateral, F—tegmen, inner, G—tegmen, lateral, H—sternite VIII, male, I—tergite VIII, male, J—male genital segments IX and X.

FIGURE 6. Merma quadriguttata (Sicard, 1909), non type (CAS), male: A—habitus, ventral, B—mouthparts, C—head, prosternum and mesoventrite, D—legs, meso and metaventrite, E—tarsal claws.

FIGURE 7. Distribution map of the Malagasy species of Merma Weise.