|
The
Eupterotidae are a small tropical family restricted to the Old World except for
two rare Neotropical taxa. They are most diverse in Africa and in the Oriental
Region. There are several rather divergent genera in Papua New Guinea, some of
which penetrate weakly into Australia; in Australia there is the subfamily
Panacelinae, consisting of a few very small species in the genus Panacela Walker.
The Australasian Anthelidae are somewhat similar in appearance and in having
hairy larvae; the relationship of this family to the Eupterotidae needs
investigation, as does the position of both families within the Bombycoidea.
Adults
The wings are large relative to the body size, the forewings deep,
triangular, with the tornus a rounded right-angle; the hindwings are
approximately circular, almost equalling the forewings in area. The scaling is
dense, usually rather coarse. The forewing venation may be diagnostic for the
family.
One radial vein has been lost, thus R1 arises from Rs within the cell, and the
latter has three branches, two arising posteriorly. Rs and R1 are closely
parallel. In the Anthelidae all radial veins are present and form a conspicuous
areole. The discal cell of Eupterotidae is usually short, perhaps only one third
the length of the wing.
The typical wing pattern is of multiple crenulate fasciation basal to a strong
double postmedial. This fasciation is often symmetrical about the disc on the
forewing but mainly distal to it on the hindwing. Modification of this pattern
is usually through reduction and simplification of fasciation. There is often
submarginal fasciation also.
The frenulum and retinaculum are weak, sometimes absent. The antennae are
broadly and evenly bipectinate in the male, more weakly so in the female.
The male genitalia in the Oriental fauna are typified by a broad, bifid uncus.
The gnathus is sometimes present. The valves are relatively simple, sometimes
divided apically. The aedeagus vesica is simple, globular, usually wholly or
partially invested with fine scobination.
The female genitalia show no strong family features. The eighth segment is
usually narrow, ring-like, and both pairs of apophyses are relatively long. The
bursa is simple, lacking a signum except in Ganisa (amongst the genera
studied). The ductus seminalis arises just subbasally on the ductus bursae.
Eggs
The eggs are dome-shaped on a flat base, the surface smooth, slightly glossy,
minutely punctate under the microscope; they are laid in clusters on the
underside of a leaf or on bark or a branch of an arboreal host-plant (Bell, MS).
Larvae
The larvae are densely invested with long secondary setae on a cylindrical body
without the lateral and sublateral protruberances and thoracic saddles that
characterise the Lasciocampidae. No definitive family characteristic has yet
been identified. That of a non-Bornean species is illustrated in Plate 19.
The larvae of Eupterote are gregarious at least during earlier instars,
whereas those of Ganisa appear to be solitary (Bell, MS). Activity is at
night.
Pupae
Pupation is in a cocoon on the soil surface, in litter or in crevices. The
cocoon is slight in Ganisa and Nisaga, dense, soft, sometimes
double in Eupterote (Bell, MS). The anterior portion of the ovoid pupa is
hemispherical, the posterior conical, terminating in a rounded cremaster with
four small, slender hooks (Ganisa), a dense tuft of hairs (Nisaga), or a
stout, short, semi-ellipsoid cremaster thickly clothed at the extremity with
hooked hairs (Eupterote) (Bell, MS).
Host-plant relationships and economic importance
Information is only available for Eupterote species and the genus Ganisa.
The former appear to have a wide range of larval diet. They defoliate a
number of plants of economic importance and thus have minor pest status. All
records for Ganisa have been on the family Oleaceae.
The Indian Nisaga simplex Walker has been reared from various grasses
(Bell, MS) and has been recorded as a pest of rice.
Habitat and behaviour
The majority of species in Borneo are encountered in lowland rainforest
where they appear to fly (or are drawn to light) mainly in the understorey
(Holloway, 1984). Eupterote muluana, E. niassana weberi and Melanothrix
latevittata have been recorded from upper montane forest, and Ganisa
plana has distinct lowland and montane races in Borneo.
Geography
The two Ganisa species are widespread in the Oriental tropics but the
rest of the Bornean fauna is either restricted to the Sunda Shelf (6 species) or
endemic (7 species). The genus Melanothrix has its centre of
species-richness in Borneo; the others are either widespread Oriental (Pseudojana,
Ganisa) or centred in the Indian Subregion (Eupterote).
The fauna of Sulawesi (three Eupterote, one Pseudojana) is wholly
Oriental, but in tropical Australia, particularly New Guinea, there is a diverse
fauna distributed
over a number of genera endemic to the region. The affinities of the fauna are
unclear, and there is considerable diversity of facies and wing-shape. The shape
of the valve and the presence of a saccus in the male genitalia may indicate a
relationship with Eupterote.
>>Forward
<<Return to Contents page
|
