Argopistes vadoni, Biondi & Iannella & D'Alessandro, 2024

Biondi, Maurizio, Iannella, Mattia & D'Alessandro, Paola, 2024, Argopistes Motschulsky from Madagascar with descriptions of six new species (Coleoptera, Chrysomelidae, Galerucinae, Alticini), ZooKeys 1202, pp. 303-327 : 303-327

Argopistes vadoni sp. nov.

Figs 7 , 8 A

Type material.

Holotype ♂: “ Coll. Mus. Tervuren / N. E. Madagascar: / Ambodivoangy VII. 1961 / J. Vadon ” [printed on white card] [15 ° 17.30 ' S; 49 ° 36.88 ' E] ( RMCA) . Paratype ♀: “ Coll. Mus. Congo / Madagascar: Antakotako / 15. i. 1939 / J. Vadon ” [printed on white card) [15 ° 12.53 ' S; 49 ° 47.61 ' E] ( RMCA) .

Diagnosis.

Argopistes vadoni sp. nov. is one of the species with black or blackish dorsal integuments, and yellow and filiform antennae, but is distinguishable by the regular elytral punctation (Fig. 7 A ). Median lobe of the aedeagus and spermatheca are both diagnostic. Median lobe of the aedeagus is easily recognizable by the apical part, distinctly slender in ventral view (Fig. 7 C ). Spermatheca is unique for the combination of pyriform basal part, distal part homogenously thickened, and ductus subapically inserted, quite thickset, moderately elongated, and uncoiled (Fig. 7 D ).

Description of the holotype

(♂). Body roundish in dorsal view (Fig. 7 A ), strongly convex in lateral view; total length of body ( LB) = 3.32 mm; maximum pronotal width at the base (WP = 2.00 mm); maximum width of elytra in the middle (WE = 2.84 mm); WE / WP = 1.42. Dorsal integuments (Fig. 7 A ) entirely black with weak blueish metallic reflections; ventral parts (Fig. 7 B ) dark reddish brown; head dark brown; frons and mouthparts brown, with yellowish maxillary palpi; antennae (Fig. 7 B ) yellowish; legs, including articulations, reddish brown, with yellowish tarsi (Fig. 7 B ). Head entirely hidden by the pronotum; vertex punctate, with a pair of large setiferous pores; frontal calli joined, clearly delimited and straight posteriorly; frons elongate, flat, roughly wrinkled; frontal ridge elongate, thin and sharp; frontogenal sutures distinctly raised; eyes large, elongate, slightly kidney-shaped; interantennal space clearly narrower than antennal sockets. Antennae (Fig. 7 B ) filiform, as long as ~ 1 / 2 the body length ( LAN = 1.76 mm; LAN / LB = 0.53); segments 1 and 2 thicker; segments 3–11 slightly and gradually flattened; LA = 100: 42: 33: 47: 47: 40: 41: 44: 43: 39: 64. Pronotum (Fig. 7 A ) distinctly transverse ( LP = 0.96 mm; WP / LP = 2.08); lateral margins strongly convergent anteriorly, weakly curved, weakly expanded, not visible in dorsal view; basal margin arcuate and distinctly sinuate; surface finely wrinkled, with very dense, small punctation; surface weakly raised parallel to the lateral margins; a large setiferous pore at the anterior angles. Scutellum small, subtriangular. Elytra ( LE = 2.98 mm; LE / LP = 3.10) strongly curved laterally (Fig. 7 A ), approx. as long as wide ( WE / LE = 0.95), jointly rounded apically; lateral margins finely bordered, visible in dorsal view; surface micropunctate; main punctation small, arranged in 9 (+ 1 sutural) regular rows, more confused along lateral parts. Humeral calli moderately raised. Macropterous. Prosternum with posteriorly open procoxal cavities and large intercoxal prosternal process. Mesosternum very short. First abdominal sternite (Fig. 7 B ) slightly longer than fifth; its central area bordered by ridges is wide, subovate. Anterior and middle legs without modifications. Posterior femora greatly swollen ( WF / LF = 0.67), elongate-subtriangular; posterior tibiae thick, distinctly shorter than femora, apically widened and prolonged into a spur-like process on inner side; outer side of hind tibia apically toothed; apical spur of hind tibiae simple, lanceolate; first metatarsomere moderately enlarged. Median lobe of the aedeagus ( LAED = 1.24 mm; LE / LAED = 2.40) (Fig. 7 C ) with smooth surface; widest at the basal opening in ventral view, slightly curved inwardly; distal part distinctly thinner, sides convergent towards the rounded apex; in lateral view median lobe weakly curved, thicker in the central third; dorsal ligula formed by a central lobe, medially incised, and two lateral lobes; its base at apical ~ 1 / 3.

Variability.

Female paratype very similar in shape and color to the holotype. LE = 3.40 mm; WE = 3.16 mm; LP = 1.00 mm; WP = 2.12 mm; LAN = 1.72 mm; LSPC = 0.34 mm; LB = 3.60 mm; LE / LP = 3.40; WE / WP = 1.49; WP / LP = 2.12; WE / LE = 0.93; LAN / LB = 0.48; LE / LSPC = 10.00. First metatarsomere in female not enlarged. Spermatheca (Fig. 7 D ) apparently wrinkled on most surface; basal part pyriform; collum short; distal part moderately elongate, apically truncate; ductus subapically inserted, quite thickset, moderately elongate, uncoiled.

Etymology.

The specific epithet refers to the collector of the new species: Jean Vadon (1904–1970) from France, one of the fathers of the entomological research in Madagascar.

Distribution.

Northern-eastern Madagascar (Toamasina province; Fig. 8 A ). Malagasy chorotype.

Ecological notes.

Host plant unknown. The two known occurrence localities fall within areas characterized by the vegetation division ‘ Malagasy Evergreen & Semi-Evergreen Forest’.

Figures

Figure 7. Argopistes vadoni sp. nov. A holotype, habitus in dorsal view B ibid, ventral view C ibid, median lobe of the aedeagus D spermatheca, from Antakotako. Abbreviations: 1 st: first abdominal sternite; 5 th: fifth abdominal sternite; ca: central area of the first abdominal sternite bordered by ridges. Scale bars: 3 mm (A, B); 500 μm (C); 300 μm (D).

Figure 8. Distribution and habitat suitability of the Argopistes species in Madagascar. A occurrence locality for each species B probability of presence of the occurrence localities, and potential suitability areas for the genus in Madagascar from ENMs.