Argopistes seyrigi, 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 seyrigi sp. nov.

Figs 6 , 8 A

Type material.

Holotype ♂: “ Coll. Mus Congo. / Madagascar: Mandraka / II. 1944 / A. Seyrig ” [printed on white card] [18 ° 54.89 ' S; 47 ° 55.61 ' E] ( RMCA).

Diagnosis.

Among the Malagasy Argopistes species, A. seyrigi sp. nov. shows strong similarities with Argopistes keiseri sp. nov. Both have the spur of hind tibiae distinctly elongated, extending significantly beyond the tibial apex (Figs 4 B , 6 B ), black dorsal integuments (Figs 4 A , 6 A ), and mostly confused elytral punctation. Argopistes seyrigi sp. nov. can be distinguished by the mostly reddish brown abdomen and tibiae (blackish in A. keiseri sp. nov.) (Figs 4 B , 6 B ). Median lobe of aedeagus of A. seyrigi sp. nov. has a clearly diagnostic value, due to the parallel sides in ventral view and the thinner apical part in lateral view (Fig. 6 C ).

Description of the holotype

(♂). Body roundish in dorsal view (Fig. 6 A ), strongly convex in lateral view; total length of body ( LB) = 3.52 mm; maximum pronotal width at the base (WP = 2.08 mm); maximum width of elytra at the middle (WE = 3.00 mm); WE / WP = 1.44. Dorsal integuments (Fig. 6 A ) entirely black with evident blueish metallic reflections; ventral parts (Fig. 6 B ) black, with mostly brownish abdomen; head black; frons and mouthparts black, with yellowish maxillary palpi; antennae yellowish (Fig. 6 B ); legs with black femora, hind tibiae dark brown, anterior and middle tibiae mostly light brown, and tarsi yellowish (Fig. 6 B ). Head entirely hidden by the pronotum; vertex punctate, with a pair of large setiferous pores; frontal calli joined, weakly delimited and weakly raised; frons short, roughly wrinkled; frontal ridge thin; frontogenal sutures quite thick and clearly raised; eyes large, elongate, slightly kidney-shaped; interantennal space clearly narrower than antennal sockets. Antennae (Fig. 6 B ) slightly shorter than 1 / 2 the body length ( LAN = 1.44 mm; LAN / LB = 0.41), filiform; segments 1–2 thicker, segments 3–11 slightly and gradually flattened; LA = 100: 46: 37: 44: 40: 39: 41: 43: 43: 38: 75. Pronotum (Fig. 6 A ) clearly transverse ( LP = 0.96 mm; WP / LP = 2.17); lateral margins strongly convergent anteriorly, straight, weakly expanded, not visible in dorsal view; basal margin arcuate and distinctly sinuate; surface microreticulate and micropunctate, with dense, small punctation; surface weakly raised parallel to the lateral margins; a large setiferous pore at the anterior angles. Scutellum small, subtriangular. Elytra ( LE = 3.16 mm; LE / LP = 3.29) strongly curved laterally (Fig. 6 A ), approx. as long as wide ( WE / LE = 0.95), jointly rounded apically; lateral margins finely bordered, visible in dorsal view; surface smooth; punctation very small, dense, less impressed than on pronotum, mostly confused, but arranged in some more impressed, barely visible regular lines, laterally. 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. 6 B ); its central area bordered by ridges is quite narrow, and slightly narrower posteriorly. Anterior and middle legs without modifications. Posterior femora greatly swollen ( WF / LF = 0.69), 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, very elongate (Fig. 6 B ). Median lobe of the aedeagus ( LAED = 1.36 mm; LE / LAED = 2.32) (Fig. 6 C ) with smooth surface; in ventral view lanceolate; in lateral view median lobe thicker in the middle part, moderately curved in the basal part, with sinuate ventral outline and straight apex; dorsal ligula formed by a central lobe, medially incised apically, and two thinner lateral lobes; its base at approx. the middle.

Variability.

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

Etymology.

The specific epithet refers to the collector of the new species: André Seyrig (1897–1945) from France, an expert on Hymenoptera : Ichneumonidae , and a tireless collector of insects and plants in Madagascar.

Distribution.

Central-eastern Madagascar (Antananarivo 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 ‘ Afromontane Moist Forest’.

Figures

Figure 4. Argopistes keiseri sp. nov. A habitus in dorsal view, male from Moramanga B ibid, ventral view C spermatheca, from Ranomafana D median lobe of the aedeagus, from left to right in dorsal, ventral, and lateral view, from Ranomafana, and two additional lateral view from Manankazo, and Maromizama. Abbreviations: as: apical spur of hind tibia. Scale bars: 3 mm (A, B); 300 μm (C); 500 μm (D).

Figure 6. Argopistes seyrigi sp. nov. A holotype, habitus in dorsal view B ibid, ventral view C ibid, median lobe of the aedeagus. Abbreviations: as: apical spur of hind tibia. Scale bars: 3 mm (A, B); 500 μm (C).

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.