Acalyptris nigrisignum Remeikis & Stonis

Stonis, Jonas R. & Remeikis, Andrius, 2015, The first records on the genus Acalyptris from the Caribbean (Lepidoptera: Nepticulidae), Zootaxa 4057 (1), pp. 79-90 : 81-83

Acalyptris nigrisignum Remeikis & Stonis , sp. nov.

( Figs 1–17 )

Type material. Holotype: ♂, CURAÇAO (formerly the Netherlands Antilles), Coral Specht, 3 km E. Willem stad, Malaise trap in mesquite-acacia desert scrub near coast, 6–15.ii.1987, W. E. Steiner & J. M. Swearinger, genitalia slide no. RA 614♂ ( USNM). Paratypes: 7 ♂, 4 ♀, same label data, genitalia slide nos RA 615♂, RA616♀ ( USNM).

Diagnosis. In male genitalia, the new species is distinguished from all known Neotropical Acalyptris except A. bicornutus (Davis, 1978) by juxta with two spine-like processes. It differs from A. bicornutus by its distinctly asymmetrical juxta and the broadly triangular lobes of vinculum (not very slender and long as in A. bicornutus , see the pictorial key in Fig. 34 ). The male’s hindwing and underside of forewing are with peculiar androconia (see Figs 5 and 6 ) which, along with the genital characters, can be useful in the diagnostics of this new species.

Male ( Figs 3–6 ). Forewing length 1.8–1.9 mm, wingspan 4.2–4.9 mm. Head: palpi cream; frontal tuft dark grey-brown to fuscous comprising a few pale ochre piliform scale on frons; collar fuscous, formed by piliform scales; eye-cap cream; antenna as long as half of forewing; flagellum with ca. 34 segments, pale brown to grey on upper side (darker at basal part), brownish cream to cream on underside. Thorax, tegula and forewing glossy, golden cream, speckled with black to grey-brown scales (sometimes more dense on tegula and forewing base, sometime on apical part of forewing). Fascia absent; cilia golden cream; underside of forewing cream, with black to grey androconia covering large area in basal half (see Fig. 6 ). Hindwing with cilia glossy cream, with black androconia on both sides; on upper side androconia form a small irregular basal patch (see Fig. 5 ); on underside androconia mostly collected in two parallel lines along wing’s margins (see Fig. 6 ). Legs cream with grey to fuscous darkenings on upper side of foreleg, sometimes on midleg too. Abdomen greyish cream to pale brown on upper side, cream to yellowish cream on underside; anal tuft short, cream; anal plates large, triangular, cream.

Female ( Fig. 2 ). Forewing length 2.1–2.2 mm, wingspan 4.7–4.9 mm. Frontal tuft fuscous on vertex, beigeorange on frons or entirely beige-orange. Flagellum with ca. 30 segments, pale brown on upper side, brownish cream to cream on underside. Forewing more densely speckled with black to grey-brown scales than in males; no androconia. Apex of abdomen broad, truncate. Otherwise as male.

Male genitalia ( Figs 7–13 ). Capsule longer (320 µm) than wide (200 µm). Vinculum with two triangular lateral (anterior) lobes ( Figs 7, 8 ). Uncus large, slightly rounded, almost truncate ( Figs 10, 11 ). Gnathos with large caudal process and very small central plate ( Fig. 9 ). Valva very simple ( Fig. 7 ), ca. 215–220 µm long, 44 µm broad at basal third which is the broadest part, without processes except short basal ones ( Fig. 7 ); transverse bar of transtilla present (long and slender). Lateral apodeme very prominent ( Figs 7, 10, 11 ). Phallus ( Figs 12, 13 ) ca. 340–360 µm long, 90–100 µm wide, with five sinuous and straight spine-like apical carinae; vesica with four or five spine-like cornuti and large cathrema.

Female genitalia ( Figs 14–17 ). Total length ca. 640 µm. Apex of abdomen very broad, slightly rounded. Vestibulum very broad, with complex sclerite and two large and two small clusters of spines ( Fig. 15 ). Corpus bursae elongate, with two very large reticulate signa (ca. 300 and 365 µm long) ( Figs 16, 17 ). Ductus spermathecae with 4.5 unusually large coils ( Fig. 16 ).

Bionomics. All type series specimens were collected in February at Malaise trap in mesquite-acacia desert scrub near coast.

Distribution. Known from Curaçao (formerly the Netherlands Antilles), about 40 km from the coast of Venezuela ( Fig. 1 ).

Etymology. The species name is derived from Latin nigra (black) and signum (a sign/picture/trace) in reference to the small but distinctive and diagnostic basal spot of black androconia on the hindwing upper side.

Figures

FIGURE 1. Distribution of Acalyptris in the Caribbean (Map—courtesy of T. Patterson, U. S. A.); * — species belong to the bicornutus complex; ** — species belong to the tenuijuxtus complex.

FIGURES 2 – 13. Acalyptris nigrisignum Remeikis & Stonis, sp. nov. 2, moth, paratype; 3, 4, forewing, upper side; 5, hindwing, upper side; 6, forewing and hindwing, underside; 7, male genitalia, capsule, holotype, genitalia slide no. RA 614; 8, same, juxta; 9, same, uncus and gnathos in glycerol; 10, 11, caudal part of genital capsule, holotype, genitalia slide no. RA 614; 12, 13, same, phallus.

FIGURES 14 – 17. Female genitalia of Acalyptris nigrisignum Remeikis & Stonis, sp. nov., paratype, genitalia slide no. RA 616. 14, general view; 15, complex vaginal sclerite; 16, coils of ductus spermathecae and signa; 17, signa.

FIGURE 34. Pictorial key to the species of the bicornutus and tenuijuxtus complexes.