Stigmella confertae Diškus & Stonis, 2016

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 : 124-126

8. Stigmella confertae Diškus & Stonis , sp. nov.

( Figs. 3 , 97–104 )

Type material. Holotype: ♀ (see Remarks), ECUADOR: Napo Province, ca. 10 km W Papallacta (páramo), 0°21'45"S, 78°11'35"W, elevation 3700–3800 m a.s.l., mining larvae on Baccharis conferta Kunth , 13.i.2005, field card no. 4862, leg. A. Diškus, J. R. Stonis, genitalia slide nos AD638♀ ( ZMUC). Paratype: 1 ♀ (see Remarks), same label data as holotype, genitalia slide no. AD642♀ ( ZMUC).

Diagnosis. The new species differs from all other known Neotropical Stigmella in the female genitalia by the combination of a very large accessory sac, small corpus bursae with indictinctive comb-like pectinations, and large pointed anterior apophyses. The host-plant Baccharis conferta also makes this species highly distinctive.

Male. Unknown.

Female ( Fig. 103 ). Head: frontal tuft ochre; collar and scape cream; antenna longer than half the length of forewing; flagellum with 27–28 segments (n=2), fuscous. Thorax and tegula fuscous. Forewing unicolorous (fascia indistinct or absent; see Remarks), fuscous with purple iridescence. Abdomen fuscous.

Female genitalia ( Fig. 104 ). Total length about 675 µm. Abdominal apex broadly rounded, about 110–120 µm broad. Anterior and posterior apophyses almost equal in lenght; anterior apophyses very broad proximally, strongly narrowing (pointed) distally; posterior apophyses 110–145 µm long, very slender. Vestibulum very broad, without sclerites. Corpus bursae with folded distal part and with broader, oval-shaped, 260–265 µm long, 180–205 µm broad, basal part, without signa; pectinations comb-like, indistintive, hardly visible ( Fig. 104 ). Accessory sac very large, folded; ductus spermathecae slender, with one distinct, strongly chitinized plate-like structure.

Bionomics. Larvae mine in leaves ( Figs 100–102 ). Host-plant: Baccharis conferta Kunth (Asteraceae) ( Fig. 98 ). Larvae bright green with dark grey-green intestine and dark brown head; mine in early January (and judging on numerous vacant leaf-mines) also in December. Leaf-mine as a gallery strongly widening and contorted in distal third (therefore resembling a blotch) ( Figs 100, 101 ). Usually but not always the distal part of leaf-mine is in distal portion of the leaf-blade ( Fig. 102 ). Black frass ( Fig. 101 ) filling most of gallery except in the final part. Old leafmines appear brownish cream, distinctive ( Fig. 102 ). Larval exit slit on upper side of the leaf. Cocoon grey-ochre to ochre; length 3 mm, maximum width 1.5–1.6 mm.

Distribution ( Fig. 3 ). This species occurs high in the equatorial Andes ( Ecuador: Napo Province) at altitudes between 3700–3800 m, in páramo habitats ( Figs 97, 99 ).

Etymology. The species is named after the host-plant Baccharis conferta .

Remarks. This distinctive high altitude new species, associated with Baccharis conferta as a host-plant, is described from the genitalia slides dissected from adults still enclosed within the pupa shell. It seems, that this species is difficult to rear indoors (mortality rate is about 90–95%; the causes of the high mortality remains unknown).

Figures

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

FIGURES 97 – 103. Stigmella confertae Diškus & Stonis, sp. nov. 97, 99, habitat, páramo, 10 km W of Papallacta, Napo Province, Ecuador, the equatorial Andes, elevation 3700 – 3800 m; 98, host-plant Baccharis conferta Kunth; 100 – 102, leafmines; 103, forewing.

FIGURES 104 – 107. Stigmella confertae Diškus & Stonis, sp. nov. and leaf-mines on Baccharis salicifolia. 104, female genitalia of S. confertae Diškus & Stonis, sp. nov., holotype, genitalia slide no. AD 638 (ZMUC); 105, 106, Baccharis salicifolia (Ruiz & Pav.) Pers.; 107, leaf-mines of unknown Stigmella species on Baccharis salicifolia.