Anarsioses, Davis Introduction, 2019

Davis Introduction, Donald R., 2019, Anarsioses, a new generic name for Phyllonorycter aberrans (Braun) (Lepidoptera Gracillariidae), Zootaxa 4701 (6), pp. 574-580 : 574-575

Anarsioses , new genus

Type species: Lithocolletis aberrans Braun, 1930 , by original designation and monotypy.

Description. Adult. Head ( Fig. 3 ). Vertex covered with long, erect, dense tuft of piliform scales; frons with broad, smoothly appressed scales extending down to bases of labial palpi; eyes enlarged, interocular index (= maximum vertical eye diameter/interocular distance at tentorial pits) ca. 1.45. Antenna ca. equal to length of forewing, smooth scaled, with a single row of slender scales per segment; scape with relatively short, dense pectin ventrally. Proboscis well developed, naked, ca. 2.9x length of labial palpus. Maxillary palpus very reduced, ca. 0.5x length of labial palpomere II, and directed laterally, consisting of 2 articulated segments. Labial palpus drooping, with 3 slender segments of almost equal length.

Thorax ( Fig. 4 ). Forewing slender, maximum length/width ratio ca. 5.2, extremely narrow at apex, reduced to an elongate lobe. Venation consisting of 7 veins extending to wing margin and a very rudimentary CuP vein ending short of wing margin near CuA; Sc extending to slightly less than basal third of costal margin; R and Rs 1 absent; Rs 2–4 present with Rs 4 arising from terminal end of cell; 1A fused with 2A and extending to distal 0.7 of hindmargin. Hindwing lanceolate, maximum width ca. 0.14 that of length; venation reduced, similar to Phyllonorycter .

Abdomen. Male genitalia ( Figs. 5‒6 ). Tegumen relatively short, triangular in ventral view. Vinculum a broadly rounded, slender, U-shaped, ventral ring. Transtilla slender. Valvae strongly asymmetrical, with right valva relatively broad and terminating in a mostly rounded, slightly clefted apex; left valva very slender, terminating in a prominently divided apex with two slender, digitate lobes. Gnathos terminating in a relatively elongate, slender lobe. Phallus ( Fig. 6 ) slender, strongly curved, with a small triangular, ventral process arising near base. Female genitalia ( Figs. 8‒9 ). Papillae anales laterally flattened, densely setose. Posterior apophyses slender, elongate. Os- tium bursae opening along caudal margin of abdominal segment 7, slightly left of median. Ductus bursae elongate, strongly curved. Accessory bursae membranous, nearly the size of corpus bursae and arising about midlength of ductus bursae. Corpus bursae with a small, U-shaped, sclerotized signum with a minutely serrated anterior margin; interior wall of corpus bursae densely covered with numerous rows of minute spines encircling signum.

Diagnosis. Morphologically, Anarsioses differs from Phyllonorycter and other Lithocolletine genera in the asymmetry of the male genitalia and eighth abdominal sternite. The right valva in Anarsioses ( Fig. 5 ) is broad with a rounded apex, and the left valva is extremely narrow with a bifurcated apex ( Fig. 5 ). The phallus is strongly curved ( Fig. 6 ), and the male eighth sternum terminates in a slender, curved lobe ( Fig. 7 ). The males of several species of Phyllonorycter also have asymmetrical valvae, but in most of these species the left valva is broad and the right slenderer. The phallus in Phyllonorycter is typically straight. The male eighth sternum also is typically symmetrical in Phyllonorycter , although in at least one North American species (i.e., P. occitanica (Frey & Boll)) the caudal apex of sternum eight is attenuated and slightly curved. In the Japanese species “ Lithocolletis ” issikii Kumata, the valvae are also asymmetrical with the left valva slenderer ( Kumata 1963). However, in this species the phallus is straight and the eighth sternum is symmetrical.

The larvae of A. aberrans differ from those of all Phyllonorycter in exiting the leaf mine to pupate ( Fig. 10 ), and from most Phyllonorycter in creating a flat, upper-surface mine. In a recent molecular phylogeny utilizing 22 genes for 96 species of Gracillariidae and representing all previously recognized subfamilies and genus groups, Anarsioses aberrans was found to comprise a clade distinct from the other members of Phyllonorycter and the other genera sampled ( Kawahara et al. 2017: fig. 2).

Etymology. The generic name is derived from the Greek anarsios (strange) and ses (moth), in reference to the strongly asymmetrical male genitalia and eighth abdominal sternite.

Figures

FIGURE 10. Larval blotch mines on Apios americana Medikus; note pupal hibernaculum in folded edge of upper middle leaf.

FIGURES 3‒4. Adult. 3. Head. 4. Wing venation.

FIGURES 5‒9. Genitalia. 5. Male genitalia, ventral view. 6. Phallus, lateral view. 7. Male sternum 8. 7. Female genitalia, lateral view. 9. Female genitalia, ventral view.