The first record of Baccharis L. (Asteraceae) as a host-plant genus for Nepticulidae (Lepidoptera), with description of new Stigmella species from South America
Author
Stonis, Jonas R.
Author
Diškus, Arūnas
Author
Remeikis, Andrius
Author
Davis, Donald R.
Author
Solis, M. Alma
Author
Torres, Nixon Cumbicus
text
Zootaxa
2016
4136
1
101
128
journal article
38648
10.11646/zootaxa.4136.1.4
d620461c-f45a-4ea5-800c-ed6298e631bd
1175-5326
261786
BBC55637-6919-43B3-BB85-83E2AFFE2CED
3.
Stigmella tripartita
Diškus & Stonis
,
sp. nov.
(
Figs. 3
,
33–43
)
Type
material
.
Holotype
: ♂ (see Remarks),
ECUADOR
:
15 km
SW Cajabamba (Chimborazo Province),
1°45'41"S
,
78°48'51"W
, elevation
3870 m
a.s.l., mining larvae on
Baccharis buxifolia
(Lam.)
Pers
.
19.ii.2007
, field card no. 4874, leg. A. Diškus, J. R. Stonis, genitalia slide nos AD
622♂
(
ZMUC
).
Paratype
: ♂ (see Remarks), same label data as
holotype
, genitalia slide no. AD
624♂
(
ZMUC
).
Diagnosis.
In the male genitalia, the set of three very large cornuti distinguishes
S. tripartita
sp. nov.
from all other
Stigmella
species; the host-plant (
Baccharis buxifolia
) also makes this species distinctive.
Male
(
Fig. 38
). Forewing length about 3.0 mm; wingspan about 6.5 mm (n=2). Head: palpi cream; frontal tuft brown to brown cream; scape cream to yellowish cream; antenna longer than half the length of forewing; flagellum with approx. 26 segments, grey.Thorax and tegula dark grey-brown to fuscous. Forewing dark brown-grey to fuscous, with slightly postmedian fascia; fascia broad to narrow, whitish grey or grey cream; terminal and tornal cilia pale grey-brown. Abdomen dark grey to fuscous (also see Remarks).
Female.
Unknown.
Male genitalia
(
Figs 39–43
). Capsule short (230–295 µm) but broad (235–240 µm). Vinculum with very small (25–30 µm), triangularly shaped lateral (anterior) lobes; ventral plate of vinculum short. Uncus 85–90 µm broad, with two small lobes, each bearing one (
Fig. 41
) or two papillae. Gnathos stout, with two caudal processes broadening basally (
Fig. 41
); central plate of gnathos large to very large, 85 µm broad, in the form of a trapezium (
Fig. 41
). Valva (
Fig. 39
) 180 µm long, 80–85 µm broad, with two apical processes (ventral process short and pointed); inner lobe almost straight or slightly bulged; transtilla with rounded sublateral processes or without processes, rounded at corners (
Figs 41, 43
). Juxta membranous, distinctly triangular, broadening caudally (
Fig. 39
). Phallus (
Figs 40, 42, 43
) very short (145–200 µm) but broad (120 µm); vesica with a set of three very large (up to 100 µm long) cornuti (
Fig. 40
); no small spinose cornuti developed.
Bionomics.
Larvae mine in leaves. Host-plant:
Baccharis buxifolia
(Lam.)
Pers
. (Asteraceae)
(
Figs 34, 36
). Larvae yellow to pale yellow, and mine in February. Contorted gallery of mine with central line of dark brown to black frass (approximately resembling the mines of the European
S. myrtilella
(Stt.))
. Larval exit slit on upper side of the leaf. Cocoon grey-beige to grey-ochre; length 2.6–3.2 mm, maximal width 1.3–1.8 mm (
Fig. 37
). Adults emerged in March.
Distribution
(
Fig. 3
). This species occurs high in the equatorial Andes (
Ecuador
) at altitudes between
3800– 3870 m
(
Fig. 33
), mostly along roadsides (
Fig. 35
).
Etymology.
The species name is derived from the Latin
tripartitus
(divided in three parts; triple) in reference to the unusual set of three very large cornuti of the male genitalia.
Remarks
. This distinctive new species, associated with
Baccharis buxifolia
as a host-plant and possessing three large cornuti in the male genitalia, is described from the genitalia slides dissected from adults still enclosed within the pupa shell.