Apisa (P.) subargentea Joicey and Talbot, 1921

Pasnik, Anna, Tarcz, Sebastian & Przybylowicz, Lukasz, 2023, A review of the subgenus Parapisa of Apisa (Lepidoptera: Erebidae: Arctiinae) with description of a remarkable species from Cameroonian Highlands, Arthropod Systematics & amp; Phylogeny 81, pp. 371-394 : 371

Apisa (P.) subargentea Joicey and Talbot, 1921

Figs 4A , 5C , 6B , 7A , 13A , 14B

Apisa subargentea Joicey & Talbot 1921, Bull. of the Hill. Mus., 1(1): 158 [ A. subargentea ] t. typica: Lake Tshohoa, Ruanda District.

Material examined.

Holotype: ♀ " Lake Tshohoa , Ruanda Dist., Cent. Afr. Aug. '19, T.A. Barns; Joicey Bequest. Brit. Mus. 1934-120"; g.s. ARCT 5795 [NHMUK]

Other material.

♂ Apisa grisescens subargentea , Joicey and Talbot; Coll. Mus. Congo, Kibali-Ituri Nioka , 7.VI.1953, J. Hecq; GS P373 ; ♂ Mus. Congo, Kibali-Ituri Nioka , 27.XI.1953, J. Hecq; GS P372 ; ♀ Burundi Gitega, 13.III.1967, Dr M. Fontaine; Coll Museum Tervuren; GS P671 ; ♀ Coll. Mus. Congo, Kibali-Ituri: Nioka , 31.V.1954, J. Hecq; GS P670; (RMCA)

Description of male (based on a specimen from Kibali-Ituri, Nioka collected 7.VI.1953).

- Head. Frons and vertex pale ochraceous; labial palpus darker, three segmented of which second is the longest and the third directed downwards, covered with short scales broader than those covering head; scapus pale ochraceous; flagellum bipectinate, concolorous with scapus; flagellomeres honey, ramii in medial part four times as long as antenna width; eye convex, indistinctly ovoid. -

Thorax.

Vestiture unicolorous pale ochraceous expressing darker or lighter tint depending on the illumination; legs of the same uniform coloration; epiphysis stout reaching 4/5 of the foretibia length; mid and hind tibia with a pair of short, terminal spurs. -

Abdomen.

Entirely pale ochraceous, concolorous with the rest of the body. Upperside similar to underside. -

Forewing.

Opaque, densely covered by flattened scales with distinct, clearly visible shine on the entire surface of the wing; scales suboval, moderately elongate, with rounded terminal margin, pale ochraceous, slightly darker along veins, with admixture of white-creamy ones in areas between them; subcostal zone up to DC indistinctly darker than remaining part of wing; veins covered by scales; cilia pale cream; R1 separated from R2-R5; M2-M3 narrowly separated; distances between M3- CuA1 and CuA1-CuA2 similar; 1A+2A almost straight, without distinct curve in one third of its length; coloration of underside similar to upperside, retinaculum present. -

Hindwing.

Coloration somewhat paler than in forewing; cilia almost white, Rs-M1 completely fused.

Male genitalia.

(Fig. 4A ) Tegumen rather narrow, slightly broadened laterally, provided with a few stout, elongate, protruding setae in dorsolateral zone. Vinculum much narrower, widely connected but not completely fused with lateral arms of tegumen. Uncus well developed, but basal margin not as broad as in Apisa cinereocostata and Apisa asipa ; distinctly narrowing until the 3/4 of its length then slightly widened forming forked termination; both tips of forks and bottom of concavity smoothly rounded; subbasal and dorsolateral portions with hairy setae. Valva subsquare, much shorter than uncus, terminal margin concave medially; outer portion of costa provided with several elongate, stiff setae; costa subbasally with a short, bulbous, sclerotized protrusion. Juxta in form of longitudinal, submedial plate fused in the subventral margin of valva. Transtilla lateral arms weakly sclerotized, almost invisible, submedian portion enlarged, fused with juxta, and forming sclerotized anellus. Saccus terminating into a lanceolate, sclerotized process about three times as long as broad. Phallus straight and short. Very similar to A. (P.) asipa sp. nov. Vesica membranous without cornuti and any sclerotization.

Female genitalia.

(Figs 5C , 6B ) Papillae anales longer than broad, sparsely covered with protruding setae slightly denser towards terminal portion; apophyses posteriores at least as long as papillae anales, narrow, needle-like; apophyses anteriores shorter than papillae anales, narrow dully ended; dorsal pheromone glands in form of two separate, elongate, membraneous, irregular shape pouches; ventral pheromone glands with single, broad, shallow opening then separated into finger-like, irregular pouches much narrower than dorsal pheromone glands; ostium small, rounder, antevaginal plate membranous; postvaginal plate well developed, sclerotized, with a pair of anterolateral extensions towards antevaginal zone; ductus bursae membranous, straight, subbasal portion narrower than widened in one third of the length; ductus seminalis slender originating from the widening; corpus bursae subsquare, delicate; signum distinctly sclerotized, granulate, in form of small, irregular plate at most twice as long as broad; sternite VII subtriangular, gradually narrowed towards distal portion, terminal zone more sclerotized, Y-shaped.

Variation.

The limited number of specimens does not allow for a proper detection of individual variation. Among the examined females it is expressed by differences in forewing length and intensity of ochraceous coloration, which may be more or less pale. Additionally, in some specimens, both males and females, the fused Rs-M1 can be forked before the termination.

Sexual dimorphism.

The female differs from the male by much shorter rami of antenna which are twice as long as the width of antenna and by shorter epiphysis reaching at most 2/3 of the foretibia length.

Distribution.

(Fig. 11 ) Known from west DRC, Rwanda, Burundi and Kenya.

Comments.

The detailed description of A. (P.) subargentea was never published. The original, very short and superficial description refers to the female ( Joicey and Talbot 1921). Already in 1960 the taxon was regarded as a synonym of A. grisescens , albeit with a question mark and no argumentation for such an action. The discovery of the male resulted in revision of the taxonomic status of the taxon and ascription to the proper subgenus ( Przybyłowicz and Kuhne 2008). Male and female genitalia were illustrated in Przybyłowicz (2009), however with only a short summary of the diagnostic characters. Given the unusual homogeneity of all members of Apisa , it is reasonable to provide a detailed redescription of both sexes amended with illustrations of the newly discovered key characters.

Figures

Figure 4. Overview of the genital apparatus of males A. (P.) subargentea (A), A. (P.) asipa sp. nov. (B) and Apisa (P.) cinereocostata (C).

Figure 5. Compilation of female genital organs A. (P.) asipa sp. nov. (A), A. (P.) cinereocostata (B), A. (P.) subargentea (C).

Figure 6. Details of female genitalia with both a marked antrum and a sclerotization of VII sternite. The arrow marks the location and sclerotization of the sternite. From left A. (P.) asipa sp. nov. (A), A. (P.) subargentea (B), A. (P.) cinereocostata (C).

Figure 7. Differences in the scale morphology of wing region between CuA 1 and CuA 2 near DC of A. subargentea (A) (tightly fitting), Apisa cinereocostata (B) (loosely fitting) and A. asipa sp. nov. (C) (sparse).

Figure 11. Distribution of Apisa (P.) cinereocostata and Apisa (P.) asipa sp. nov. Orange dots represent the localities of A. (P.) cinereocostata, purple dots A. (P.) asipa sp. nov., blue dots A. (P.) subargentea. The blue triangles indicate the literature location of A. (P.) subargentea.

Figure 13. SEM image showing the differences between scale shape of Apisa (P.) subargentea (A) (flattened, convex termination), A. (P.) cinereocostata (B) (flattened, concave termination) and A. (P.) asipa sp. nov. (C) (narrow, needle-like).

Figure 14. Differences in the forewing transparency. Apisa (P.) asipa sp. nov. (A), wing transparent; A. (P.) subargentea (B), wing opaque; A. (P.) cinereocostata (C, D), wing semitransparent.