Argopistes laterosinuatus, 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 laterosinuatus sp. nov.

Figs 5 , 8 A

Type material.

Holotype ♀: “ Coll. Mus. Congo / Madagascar: Antakotako / 15. i. 1939, J. Vadon ” [printed and handwritten on white card] [15 ° 12.53 ' S; 49 ° 47.61 ' E] ( RMCA).

Diagnosis.

Argopistes laterosinuatus sp. nov. is easily recognizable among the Afrotropical Argopistes species due to its subovate outline in dorsal view (Fig. 5 A ) and sinuate sides in lateral view (Fig. 5 C ). Spermatheca is also diagnostic, due to the combination of pyriform basal part, with a distinct protrusion close to the collum, apical part clearly narrowing towards the apex, and ductus ventrally inserted, thickset, uncoiled (Fig. 5 D ).

Description of the holotype

(♀). Body largely subovate in dorsal view (Fig. 5 A ), very convex in lateral view (Fig. 5 C ); total length of body ( LB) = 3.18 mm; maximum pronotal width at the base (WP = 1.80 mm); maximum width of elytra at the basal third (WE = 2.72 mm); WE / WP = 1.51. Dorsal integuments (Fig. 5 A ) reddish brown with weak metallic reflections; ventral parts (Fig. 5 B ) light brown; head light brown; frons and mouthparts light brown; antennae (Fig. 5 B ) with segments 1–5 yellowish, 6 dark brown, 7–10 black, 11 black but distally lighter; legs entirely light brown (Fig. 5 B ). Head entirely hidden by the pronotum; vertex with small, irregular punctation, and a pair of large setiferous pores; frontal calli joined, moderately raised, with V-shaped posterior delimitation; frons moderately elongate, flat, roughly microreticulate; frontal ridge short; frontogenal sutures distinctly raised; eyes large, elongate, slightly kidney-shaped; interantennal space clearly narrower than antennal sockets. Antennae (Fig. 5 B ) clavate, slightly shorter than 1 / 2 the body length ( LAN = 1.36 mm; LAN / LB = 0.43); LA = 100: 36: 53: 47: 48: 52: 44: 46: 49: 52: 79. Pronotum (Fig. 5 A ) strongly transverse ( LP = 0.80 mm; WP / LP = 2.25); lateral margins strongly convergent anteriorly and slightly folded ventrally, weakly curved, weakly expanded, not visible in dorsal view; basal margin arcuate and distinctly sinuate; surface finely microreticulate, with very small and dense punctation; surface weakly raised near the lateral margins; a large setiferous pore at the anterior angles. Scutellum small, subtriangular. Elytra ( LE = 2.92 mm; LE / LP = 3.65) slightly longer than wide ( WE / LE = 0.93), strongly curved laterally in dorsal view (Fig. 5 A ) and distinctly sinuate in lateral view (Fig. 5 C ), jointly rounded apically; lateral margins finely bordered, visible in dorsal view; surface subsmooth, with very small and moderately dense, mostly confused punctation; slightly larger punctures are arranged in 9 (+ 1 sutural) regular rows. Humeral calli moderately raised. Macropterous. Prosternum with posteriorly open procoxal cavities and large intercoxal prosternal process. Mesosternum very short. First abdominal sternite approx. as long as fifth (Fig. 5 B ); its central area bordered by ridges is wide, rounded anteriorly, laterally subparallel. Anterior and middle legs without modifications. Posterior femora greatly swollen ( WF / LF = 0.61), 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. Basal part of the spermatheca pyriform, with a distinct ventral protrusion close to the distal part (Fig. 5 D ); collum short, apical part short, narrowing towards the apex; ductus ventrally inserted, thickset, moderately elongate, uncoiled; LSPC = 0.32 mm; LE / LSPC = 9.13.

Variability.

Only the female holotype of the new species is known so far.

Etymology.

The specific epithet refers to the sinuate lateral margin of each elytra, a character absent in all other Argopistes species known to date for Madagascar.

Distribution.

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

Ecological notes.

Host plant unknown. The only known occurrence locality falls within an area characterized by the vegetation division ‘ Malagasy Evergreen & Semi-Evergreen Forest’.

Figures

Figure 5. Argopistes laterosinuatus sp. nov. A holotype, habitus in dorsal view B ibid, ventral view C ibid, lateral view D ibid, spermatheca. Scale bars: 3 mm (A, B, 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.