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Nyctemera Hubner
Type species: lacticinia Cramer.
Synonyms (including subgenera): Deilemera Hübner (type species evergista
Cramer); Agagles White (type species amicus White); Leptosoma
Boisduval (type species annulatum Boisduval; praeocc., as is the
replacement name Amathes Gistl (Watson, Fletcher & Nye, 1980)); Trypheromera
Butler (type species plagifera Walker); Zonosoma Butler (type
species cenis Cramer; praeocc., as is the replacement name Tristania Kirby
(Watson, Fletcher & Nye, 1980)); Arctata Roepke (type species arctata
Walker); Coleta Roepke (type species coleta Cramer).
The taxonomy of this genus was reviewed in two papers by Roepke (1948,
1957) who concentrated particularly on the Sundanian fauna and made extensive
examinations of type material. Full synonymy for the species discussed below may
be found in his papers, as well as accounts of the various races of the species.
Nyctemera species are extremely diverse in the Indo-Australian tropics and are
also found at much lower diversity in Africa and Madagascar. They are mainly
day-flying and this is reflected in the dark sclerotisation of the abdomen when
macerated and dissected. Some are taken by day and at light at night; a few only
come to light at night (the arctata group).
All species have grey, brownish grey or blackish forewings and hindwing
borders. The rest of the hindwing is white and there are white markings on the
forewing, almost invariably a postmedial band. The antennae are narrowly to
broadly bipectinate in both sexes though pectinations are usually less developed
in the female. The thorax is spotted or striped with black. It and the abdomen
are pale grey or dark yellow, the apex in grey species often yellow also. The
abdomen is either ringed with black on each segment or has a weak longitudinal
dorsal stripe or row of spots; species with yellow abdomens tend to have
segmental rings.
In the male genitalia the uncus is often modified with humps, hooks or
flanges. The valves tend to have a broad, basal, saccular zone and a robust
hook- or paddle-like distal zone, and usually a process or flap from the base of
the valve costa. The aedeagus vesica is usually small, a single lobe, sometimes
narrow, curved, sometimes scobinate.
The female genitalia have the dorsal glands of the ovipositor lobes
long, slender, sometimes fused basally. The distal margin of the seventh
sternite is robust, often modified, with the ostium just distal to it. It is
often sclerotised at the junction with the tergite distally, forming a small
pocket or groove with which the male valve may articulate. The bursa is large, usually with a single scobinate signum.
Roepke (1949), though erecting two subgenera for Nyctemera, did
not provide any strong definitions of species groupings within the genus.
Bornean species fall within two main groupings within which there are
subgroupings. These are now discussed in the hope they may provide some guidance
for a future revision of the genus.
The first five species belong to a group where the hindwing dark border
has a projection from its inner margin at vein CuA2. The abdomen is pale grey
with black rings. The valve of the male genitalia is broadly bifid apically. The
trio of lacticinia, baulus and sonticum share the feature of an
ellipsoid uncus with a ventral flange. They have a flat rhomboidal signum in the
bursa of the female as in the tripunctaria group and a ribbon-like,
sigmoid, sclerotised ductus bursae. The other two species have a signum that
protrudes into the bursa convexly (umbonate) and is not conspicuously
rhomboidal. N. ludekingii has a signum as in the latter two species, a
bifid valve, but the abdomen is yellow rather than pale grey. The wing pattern
is markedly modified,. N. coleta has an umbonate signum and weakly bifid
valves; the ductus bursae is as in the lacticinia trio. But the abdomen
is not ringed black, having only a dorsal row of black spots.
The second group is characterised by a pale grey abdomen with a dorsal
row of black spots and a valve in the male genitalia with a strong flap at the
base of the costa and a strong, often hook-like distal portion of the valve. The
female signum is rhomboidal, flat. Within the group, tripunctaria, kiauensis and
tenompoka have the uncus with a bifid dorsal process (also seen in the
Sumatran and Peninsular Malaysian taxa clarior Roepke and corbeti Roepke).
N. tripunctaria (females of the other two are unknown) shares with N.
regularis (with an unmodified uncus) a ‘pinched up’ ridge on the female
lamella antevaginalis. Features of the uncus, tegumen, aedeagus and valve apex
delimit another species pair, kinibalina and calcicola, as
discussed in the description of the latter. N. adversata has characters
of the abdomen and male genitalia that also place it in this group.
These two groups have white wing markings that are convex in the spaces
relative to the grey or black and represent typical Nyctemera; the
intersegmental membrane between segment eight and the male genitalia is
expanded, crinkled and finely scobinate. The third group is characterised by
white markings that are concave in the spaces relative to the grey. The wings
tend to be diaphanous in many species. The abdomen is yellow with black rings.
Whilst the first two groups have longitudinal dark streaks on the pale grey
thorax, in this third group the dark markings tend to be punctate on yellow. The
male eighth tergite has prominent apodemes; those are weak if present in typical
Nyctemera. The female has a single signum in the bursa, or none. The name
Deilemera Hübner (=Arctata Roepke) is available for this group.
The Bornean taxon abraxoides Walker in the Pitasila Moore
group, usually referred to under Nyctemera, has been transferred to Utetheisa
(Utetheisa pulchelloides
Hampson).
Amongst the Arctiinae the female bursa commonly has two signa. Tyria Hübner
has a single signum. Roepke (1949) drew attention to the possibility that this
genus was close to Nyctemera, and to the fact that Tyria jacobaeae Linnaeus
is also recorded as specific to Senecio in the Compositae. Thus the two
genera could probably be associated together within the tribe Nyctemerini of the
Arctiinae (e.g. as in Freina & Witt (1987) at a subfamily level), but this
may be subordinate to the Callimorphini.
Most host-plant records for Nyctemera are from the Compositae: Cineraria,
Crassocephalum, Emilia, Erechtites, Erigeron, Gynura, Picris, Senecio (Roepke,
1949; McFarland, 1979; records in accounts of the species below). Such plants
tend to grow as weeds in open or disturbed habitats, and the moths are most
often encountered in such situations. They may sequester toxins from the plants
and advertise the fact through their aposematic coloration.
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