Archithosia (Acanthosia) parva Durante & Potenza, 2025

Durante, Antonio, Potenza, Luigi & Pellegrino, Gabriele, 2025, Revision of the subgenus Acanthosia Krüger, 2015 in the genus Archithosia Birket-Smith, 1965, with a description of four new species (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Zootaxa 5659 (3), pp. 407-425 : 421

Archithosia (Acanthosia) parva Durante & Potenza sp. nov. ( Figs. 5F ; 9 )

Holotype: ♀, GABON, Ipassa (Makokou), 500 m, 0°30'43"N 12°48'13"E, 19-2/ 11-3-2011, Durante leg., gen. sl. n. 1218 MAD; in coll. MSNS.

Diagnosis. This species can easily be identified thanks to its small size. However, the capture of only one specimen does not allow us to consider this character as stable and certain. In any case, the forewings are more slender than those of other Archithosia species (length/width ratio 3.16, see Discussion for comments).

As usual in this genus, genital morphology represents the most concrete diagnostic feature: the broad cylindrical ductus and the pouch-like corpus are clearly diagnostic.

Description. ( Fig. 5F ). Wingspan ♀ 21 mm. Head with posterior region vertex beige, anterior region (between antennae) ochreous yellow; frontoclypeus darker beige than vertex; antennae ciliated, dorsally yellow, ventrally unpigmented; labial palpi porrect, not extending beyond frons, same colour as posterior region of vertex.

Patagia, tegulae and notum same colour as posterior region of vertex, patagia yellow bordered; thorax ventrally like the frontoclypeus. Legs same colour as thorax sternites, with distal end of femurs darkening; spurs formula 0- 2-4. Forewing upperside ground colour ochreous yellow, slightly dusted with beige, with one black dot at middle of costa and one smaller dot in middle of space between veins CuA2 and 1A+2A. Forewing underside unmarked, light ochreous yellow with costa and termen more intense. Hindwing upperside and underside unmarked, ground colour straw yellow with slightly darker margins. Fringes concolorous with margins.

Abdomen same colour as thorax sternites,with anal tuft slightly lighter.A2 sternum apodemes long(plesiomorphic character according to Bendib & Minet (1999: 243), but see also Holloway (2001: 281)). Seventh abdominal sternite as long as sixth, broadening slightly along the pleurae; seventh tergite twice as long as sixth. Eighth abdominal sternite coincident with lamella postvaginalis; eighth tergite about 1/3 as long as sixth tergite.

Genitalia. ♀ ( Fig. 9 ). Seventh sternite membranous with caudal margin (ca) swollen; lamella antevaginalis (la) slightly sclerotised, bar-like, laterally not well delimited, at least 1/3 as broad as seventh sternite caudal margin. Lamella postvaginalis (lp) well sclerotised, trapezoidal, almost as broad as whole eighth sternite, with caudal margin bearing U-shaped sclerotization (us) with incision in middle.

Papillae anales (pa) smoothly squarish; anterior apophyses quite stout, about 1/2 as long as sixth sternite; posterior apophyses slender, about as long as sixth sternite; dorsal pheromone glands (pg; Fig. 9B ) unpaired, with one caudal opening at intersegmental membrane between A8 and A9, anteriorly deeply bifurcated into two finger-like lobes, 2/3 as long as posterior apophyses.

Ductus bursae (db) quite sclerotised, roughly cylindrical, with surface wholly scobinate ( Figs. 9C, E ), slightly shorter than seventh sternite, caudally and cephalically narrower and more membranous, with ductus seminalis (ds; Fig. 9B ) arising from caudal end on right; corpus bursae (cb) membranous, pouch-like, with entire surface scobinate, forming fold at linkage to ductus; signum (si; Fig. 9D ) ventral, nearly in middle, concave, with scobination of tiny spines.

Etymology. The name of this species derives from the Latin “parvus”, meaning small, referring to its general size.

Figures

FIGURE 5. Archithosia (Acanthosia) species. A. A. flavifrontella, male, g. sl. n. 1251 MAD, Ipassa, Gabon. B. A. flavifrontella, female, g. sl. n. 1318 MAD, Ipassa, Gabon. C. A. oblonga sp. nov., holotype, female, g. sl. n. 1207 MAD, Ipassa, Gabon. D. A. brevis sp. nov., holotype, female, g. sl. n. 1280 MAD, Ipassa, Gabon. E. A. tryphosa, holotype, male, Arctiidae genitalia slide n. 44 BMNH, Ruwenzori Range, Bwamba Pass, Uganda. F. A. parva sp. nov., holotype, female, g. sl. n. 1218 MAD, Ipassa, Gabon.

FIGURE 9. A. parva sp. nov., holotype, female, g. sl. n. 1218 MAD, Ipassa, Gabon, genitalia. A. Abdomen from V segment backwards, ventral view. B. Dorsal pheromone glands, dorsal view. C. Ductus bursae, dorsal view, enlarged. D. signum, ventral view, enlarged. E. Ductus bursae, dorsal view, granicula, enlarged. ca caudal margin of VII sternite; db ductus bursae; ds ductus seminalis; cb corpus bursae; la lamella antevaginalis; lp lamella postvaginalis; pa papillae anales; pg dorsal pheromone glands; si signum; VII st seventh sternite; us U-shaped sclerotization of VIII sternite.