Acalyptris trigonijuxtus 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 : 83-84

Acalyptris trigonijuxtus Remeikis & Stonis , sp. nov.

( Figs 1 , 18–22 )

Type material. Holotype: ♂, BRITISH VIRGIN ISLANDS, Guana Island, elevation 60 m, at light (near Clubhouse), 9–15.vii.1985, S. E. & P. M. Miller, genitalia slide no. RA612 ( USNM).

Diagnosis. A. trigonijuxtus is a pale moth with no androconia on forewing or hindwing but with triangular juxta and long lateral lobes of vinculum in the male genitalia. It differs from Acalyptris tenuijuxtus (Davis, 1978) and A. unicornis Puplesis & Robinson, 2000 , which are probably most related to it, in the shape of apically pointed and strongly thickened juxta (see pictorial key in Fig. 34 ) as well as from A. tenuijuxtus , in the pale forewing and from A. unicornis , in the longer vinculum, shape of apical carinae and particularly in the shape of cornutus.

Male ( Fig. 18 ). Forewing length 1.7 mm, wingspan 3.6 mm. Head: palpi cream; frontal tuft brownish cream; collar cream, formed by piliform scales; eye-cap yellowish cream; antenna as long as half of forewing; flagellum with 28 segments, cream with some pale brown scales. Thorax, tegula and forewing glossy, golden cream, irregularly speckled with some brown scales; cilia and underside of forewing entirely cream with faint golden gloss, without androconia. Hindwing and its cilia cream, without androconia. Legs cream. Abdomen cream on both upper and underside; anal plates cream; anal tuft short, cream.

Female. Unknown.

Male genitalia ( Figs 19–22 ). Capsule longer (290 µm) than wide (170 µm). Vinculum with two large (long) lateral lobes ( Fig. 22 ). Pseuduncus slender (as in fig. 30), turned and therefore hardly visible in a permanent slide (see Fig. 22 ). Uncus with two short and two longer caudal projections and one ventral projection ( Fig. 19 ). Gnathos with pointed caudal process, tiny central element and broad lateral arms ( Fig. 19 ). Valva very simple ( Fig. 22 ), 170 µm long, 30 µm broad at the middle (the broadest part), with short basal processes ( Fig. 22 ); transtilla absent. Lateral apodeme very prominent ( Fig. 22 ). Phallus ( Fig. 20 ) 255 µm long, 80 µm wide, with two short straight apical carinae; vesica with single but very large sinuous cornutus and large cathrema ( Fig. 20 ).

Bionomics. Collected at light in July. Otherwise unknown.

Distribution. Known from single locality in British Virgin Islands ( Fig. 1 ).

Etymology. The species name is derived from Latin trigonium (a triangle) and juxta (a sclerite between valvae) in reference to the triangularly shaped juxta in the male genitalia.

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.

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

FIGURES 18 – 22. Acalyptris trigonijuxtus Remeikis & Stonis, sp. nov. 18, moth, holotype; 19, caudal part of male genital capsule, temporary mount in glycerol, holotype; 20, phallus, permanent genitalia slide no. RA 612, holotype; 21, same, juxta; 22, general view of genital capsule, permanent genitalia slide no. RA 612, holotype.