Type species: astheniata Guenée.
In the shape and marking of the hindwing tail this genus resembles
microniines in the genera Pseudomicronia Moore and Strophidia Hübner,
also the white ground colour of the wings and buff-grey of the fasciae and
striae is similar. However, the fasciation is much simpler, consisting primarily
of three strong, straight fasciae on the forewing and two on the hindwing. There
is some resemblance to the ennomine geometrid genus Ourapteryx Leach.
The male abdomen has the seventh and eighth sternites narrowing to a
point, the latter almost vestigial: the eighth tergite is longer, rectangular,
but narrower than the seventh, with a square excavation in its anterior margin.
In the genitalia the uncus is short, triangular, with finely setose lateral
margins. There is no gnathus, but the subscaphium is sclerotised. There is a
prominent anellar ring, and the saccus (flexed upwards in the preparation
illustrated) is broadly triangular. The valves are large, ovate, with extensive
fine, angled pleating over the ventral part and a somewhat complex costa with
several interiorly directed processes. The aedeagus vesica has a large,
irregular terminal cornutus.
In the female the ovipositor lobes have oblique (produced dorsally)
margins. The ductus is sclerotised, with a colliculum. The corpus bursae expands
distally and is somewhat convoluted, with an irregular ring of scobinate
sclerotisation at one third.
Bigger (1988) described (as astheniata) the larva of the closely
related Solomon species, U. hyemalis Butler, as pale green with irregular
bands of red spots in longitudinal stripes. It feeds in the upper part of the
leaves beneath a web on the surface of the host foliage, with faecal pellets
plastered on the underside of the web, obscuring the larvae. Several ages of
larva can be found in one web, suggesting that females will lay preferentially
on established webs to ensure early protection for the larvae. Eggs are laid on
the outside of the webs. However, in Borneo (D.C. Lees, pers. comm.), later
instars of astheniata are extremely antagonistic to each other. If
another larva is introduced to a web, the occupant will thrash violently until
the other is expelled. Cyphura larvae also live in webs but are solitary.
The host-plants are always species of Endospermum
(Robinson, 1975; Bigger, 1988; Urapteroides
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