Stigmella

Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Davis, Donald R., Solis, M. Alma & Torres, Nixon Cumbicus, 2016, The first record of Baccharis L. (Asteraceae) as a host-plant genus for Nepticulidae (Lepidoptera), with description of new Stigmella species from South America, Zootaxa 4136 (1), pp. 101-128 : 111-115

4. Stigmella species 610

( Figs. 3 , 44–51 )

Material examined. ♀, ECUADOR: Loja Province, 45 km S Loja, western environments of Vilcabamba, 4°15'21"S, 79°13'8"W, elevation 1800 m a.s.l., mining larvae on Baccharis obtusifolia Kunth , 14.ii.2014, leg. A. Remeikis & J. R. Stonis, genitalia slide no. RA610♀ ( ZMUC).

Diagnosis. Externally, this golden irridescent moth resembles only the similarly colored Peruvian S. andina Meyrick (see illustrated in Puplesis & Robinson 2000: fig. 209) from which it differs in the distinctly broad abdominal apex and distally narrowing anterior apophyses in female genitalia; in contrast to S. andina , posterior apophyses are more or less straight (not outwardly bent as in S. andina ). From all newly described species in this paper, which are dark and with fascia, it clearly differs externally; also see female genitalia comparison provided in Figs 51–54 . Stigmella species 610 is recognisable by the very large accessory sac and shape of the apophyses ( Fig. 51 ); the host-plant, Baccharis obtusifolia , also makes this species distinctive.

Male. Unknown.

Female ( Figs 49, 50 ). Head: palpi golden cream; frontal tuft ochre-brown; collar and scape golden cream to yellowish cream; antenna longer than half the length of forewing; flagellum with approx. 30 segments (n=1), yellowish grey, glossy.Thorax and tegula golden cream. Forewing golden cream except small fuscous spot at base and fuscous apical ¼; cilia brownish cream to golden cream. Abdomen dark brown on upper side, golden cream on uderside (also see Remarks).

Female genitalia ( Fig. 51 ). Total length about 660 µm. Abdominal apex broad (130–135 µm), distinctly truncate. Broad apophyses anteriores slightly longer or equal to very narrow apophyses posteriores. Vestibulum relatively broad, without sclerites. Accessory sac very large and folded. Ductus spermathecae narrow, with 1.5 coils (chitinized convolution) (see Fig. 51 , enlarged). Corpus bursae round, covered with numerous comb-like pectinations but without signa (see Fig. 51 , enlarged).

Bionomics. Larvae mine in leaves ( Figs 47, 48 ). Host-plant: Baccharis obtusifolia Kunth (Asteraceae) ( Fig. 45 ). Egg on upper side of leaf. Larvae pale green with brownish green intestine and pale brown head; mine in February. Leaf-mine long, starting on underside (which is unusual for the most of Nepticulidae ), occasionally on upper side of leaf-blade as a long narrow gallery filled with dark brown frass; later mining continues on upper side of leaf-blade only; leaf-mine contorted and abruptly widening, with central line of black frass. Larval exit slit on upper side of the leaf. Cocoon pale grey-beige; length 2.6–3.2 mm, maximal width 1.3–1.8 mm. Adults emerged in March.

Distribution ( Fig. 3 ). This species occurs in the equatorial Andes ( Ecuador) on rocky slopes at altitudes about 1800 m ( Fig. 33 ), predominantly in dry tropical forest habitat ( Figs 44, 46 ).

Remarks. Description of external features are based on a single completely developed female pupa. This externally distinctive new species, associated with Baccharis obtusifolia as a host-plant is left unnamed until more material will be collected.

Figures

FIGURE 3. Current records of Stigmella species feeding on plants from the genus Baccharis L.

FIGURES 44 – 50. Stigmella species 610. 44, 46, habitat, Vilcabamba, S of Loja, Ecuador, the equatorial Andes, elevation 1800 m; 45, host-plant Baccharis obtusifolia Kunth; 47, 48, leaf-mines; 49, pupa, ventral view; 50, same, lateral view.

FIGURES 51 – 54. Female genitalia of Stigmella species feeding on Baccharis (ZMUC). 51, S. species 610; 52, S. latifoliae Remeikis, Diškus & Stonis, sp. nov., not belonging to the type-series; 53, S. baccharicola Diškus & Stonis, sp. nov., not belonging to the type-series; 54, S. species 609.

FIGURES 33 – 38. Stigmella tripartita Diškus & Stonis, sp. nov. 33, habitat, SW of Cajabamba, Chimborazo Province, Ecuador, the equatorial Andes, elevation 3870 m; 34, 36, host-plant Baccharis buxifolia (Lam.) Pers.; 35, usual habitat of the species occurrence along roadsides; 37, cocoon; 38, forewing (reconstructed).