Macrocneme immanis Hampson, 1898

Hampson, G. F. (1898). Catalogue of the Lepidoptera Phalaenae in the British
Museum, vol. 1, Catalogue of the Syntomidae in the collection of the British
Museum. London: pp. 320-321, pl. XII, fig. 1 (as Macrocneme immanis, n. sp.).

♂. Black; antennae white at tips; frons with lateral white points; tegulae
with lateral and dorsal white points; pectus, stripes on coxae and femora, and
the fringe of hind tarsi white; abdomen with subdorsal and lateral white
points on 1st segment, the other segments suffused with dark green, the
ventral surface white on basal half, reduced to bands on terminal. Fore wing
suffused with dark metallic green to end of cell. Hind wing with dark green
patch in, below, and beyond lower end of cell.

♀. Base of palpi, coxae, and base of femora with white points; abdomen with
white ventral band at base, the other segments with ventral series of points,
and the 2nd and 3rd segments with lateral points.

Hab. Bolivia, Chaco, 1 ♂ 1 ♀, type. Exp. 52 millim.

Dietz, R. E. IV (1994). Systematics and biology of the genus Macrocneme Hübner
(Lepidoptera: Ctenuchidae). University of California Publications in
Entomology 113: pp. 49-50 (Figs. 35-38, 169-170, 210; Map 12).

Macrocneme immanis Hampson
Macrocneme immanis Hampson, 1898: 320-321, pl. XII, fig. 1

A comparatively large Macrocneme with a characteristic dull iridescent sheen
of the wings. This is the most commonly collected member of a species complex
that includes two new sympatric species, M. habroceladon and tarsispecca. The
appearance and distribution of the three are so similar that only the male
genitalia will separate them. M. immanis males differ slightly externally by
having more extensively white hind tarsi and prominent white scaling on the
underside, especially basad on the abdominal venter. The identification of
females is difficult due to the lack of characters for properly associating
the sexes within the complex. The structure of sternite VII is sufficiently
different to distinguish tarsispecca from immanis. The female of habroceladon
is unknown.

MALE. Head: blackish brown, occiput with iridescent green spots; labial palpi
reaching base of antenna, segment II slightly porrect. Thorax: blackish brown,
iridescence dull green; metallic scales on disc obscured by overlying
hair-like scales; metallic spots on patagia small; tegulae with scattered
metallic scales along anterior and mesal margins, white absent from underside;
pectus brown interspersed with white, white spots on pleura above coxae and on
metepimeron; legs blackish brown, inner margins of coxae, femora, and tibiae
streaked with white, hind coxae and fringe of entire tarsi prominently white.
Forewing: brown, basal half suffused with dark metallic green to end of cell,
distal margin of iridescence not sharply delineated, basal black scales absent
or scarce; underside similar, except iridescence greenish blue, depending on
angle of light, tip of retinaculum white. Hindwing: brown with dark green
iridescent patch in discal area; underside entirely suffused with blue-green
iridescence, except narrowly at apex. Abdomen: dorsum suffused with dark green
iridescence, shiny longitudinal striae absent; basal two segments of venter
mostly white, remaining segments with small mesal spot, pleura with two white
spots basally. Genitalia: as in Figs. 35-38 (drawn from RED prep. 39223, SMM,
5n); dorsal arms (claspers) of valvae symmetrical, inner margins without
indentations; uncus skewed slightly to left when viewed above, dorsum round,
lateral margins horizontally flanged; apex of juxta quadrate, extending
slightly beyond base of ventral processes, spines absent; aedeagus with two
spines, longest on left with surface prominently spinose, short stubby spine
on right with apex occasionally blunt.

FEMALE. Essentially identical to male except: Thorax: less white on underside
of pectus and legs; inner margins of coxae, femora, and tibiae dark brown with
scattering of white scales along mesal margin of forecoxae and in hindcoxal
grooves. Abdomen: white on venter restricted to mesal series of small spots,
with larger pair laterally on basal segment; pleura white spotted on basal two
segments, smaller spots on remaining distal segments. Genitalia: as in Figs.
169-170 (drawn from RED prep. 268, SMM, 2n); sternite VII of sterigma
shield-shaped, apex cephalad, broad, skewed to left; caudal margin slightly
convex mesad, with small independent pocket in intersegmental membrane;
sclerotized band from margin of encircling pleurite at right; fold of lamella
antevaginalis half as wide as overlying sternite VII; sub-ovoid sclerite of
lamella postvaginalis decurved slightly along ostial opening; sternite VII
with two prominent plicae, one unattached at left, the other appended from
mesal prominence; ductus bursae and stalk of accessory bursa with concentric
plicae; thickened plicae in dorsal wall of ductus bursae; opposing,
scallop-shaped signa with recumbent spines in bursa copulatrix.

VARIATION. Length of forewing: males, 21.7-23.7 mm; females, 21.5-23.2 mm.
Wings are normally brown suffused with a muted green iridescence, but
occasionally the ground color is a brownish black (Rio Pampas, Peru) or the
iridescence is a muted blue (San Pedro, Argentina; Rio Pampas, Peru). In
males, the white scaling on the underside is variable, occasionally sparse or
entirely lacking along the inner margins of the femora and tibiae of the
forelegs, tibiae of the hindlegs, or as thin, transverse bands on abdominal
venter (Chaco, Bolivia; Yungas de Incachaca, Bolivia).