Nygmia Hübner Gen. rev.
Type species: icilia Stoll, India.
Synonyms: Adlullia Walker (type species lunifera Walker, Sulawesi)
syn. n.; Miccotrogia Toxopeus (type species tamsi Collenette,
Peninsular Malaysia, Sumatra) syn. n.
Undoubtedly, the concept of Nygmia presented here will require
further revision in future, as there are obviously many distinct subgroups
within it, and its monophyly is not clearly supported. However, it is probably a
better placement for the larger more robust Indo-Australian species than is Euproctis
(see also Toxopeus (1948)).
The facies differs from that of the genera treated up to this point in
that the forewing usually has a black discal dot. The forewing venation is
similar to that of most Nygmiini genera, with R5 branching off more basally from
the Rs system than R2. Rs and M1 are usually stalked in the hindwing, and M3 and
CuA1 vary from being moderately stalked to arising independently; M2 is present.
The most consistent feature is in the uncus, which tends to be slender,
digitate, and separated in a rather posterior position from the tegumen by a
more membranous sclerite. The valves tend to be slender, divided, or spiny,
often rather reduced. The aedeagus vesica is usually massive, elongate, with the
distal zone densely and evenly spined, or with a band of spines (possibly
homologous with the distal appendix of Toxoproctis). The base of the
vesica and/or apex of the aedeagus may have a further field of spines. The
aedeagus may also have a prominent hook or spur arising from anywhere between
the centre to the apex.
Females usually have complex lamellae vaginales and ostium, with a very
long, usually corrugated or fluted ductus that expands into a pyriform bursa.
The signum is often present and is frequently a longitudinal (rather than
transverse) flange arising from a sclerotised plate in the wall of the bursa.
The biology of some of the species is described below. T.R.D. Bell (MS)
reared N. icilia in India. The larva is dull blackish, banded
longitudinally with yellow and marbled with brown, and the ventral surface is
jet black. The verrucae are surrounded narrowly by yellow. Those above the
spiracles have a carpet-like pile of hairs, deep fawn in colour. The longer
setae are a mixture of moderate plumose brown and long white ones.
The larvae spend most of their life gregariously, separating only when
nearly fully grown. Pupation is in a well woven, silken cocoon, concealed in
leaves or a bark crevice.
The host-plant was Loranthus (Loranthaceae). The mistletoe family
has been recorded for a few other species also.
The genus also appears to be well represented in Sulawesi and the
Australasian tropics, and dissection indicates it should probably include the
following species (and their close relatives, though these are not formally
transferred): N. discophora Snellen comb. n. (Sulawesi); N.
ochreata Walker comb. n. (Ambon); N. aeruginosa Collenette comb.
n. (New Guinea); N. araucaria Collenette comb. n. (New
Guinea); N. panselena Collenette comb. n. (New Guinea); N.
rubida Bethune-Baker comb. n. (New Guinea); N. rubroradiata Bethune-Baker
comb. n. (New Guinea); N. sublutea Bethune-Baker comb. n.
(New Guinea); N. arrogans Lucas comb. n. (Australia); N.
habrostola Turner comb. n. (Australia).
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