Ozola Walker
Type species: microniaria Walker, Sri Lanka.
Synonyms: Carima Walker (type species basisparsata
Walker); Desmobathra Meyrick (type species niphoplaca Meyrick,
Solomons); Tosaura Swinhoe (type species falcipennis Moore); Zarmigethusa
Walker (type species macariata Walker, Seram).
Species of Ozola are generally small with narrow, acute, often
falcate or even bifalcate forewings. The facies is brown with finely lineate
fasciation, or white with grey to dark grey suffusion or patches. In the eastern
Australasian subgenus Desmobathra the wings are yellow.
In the male genitalia the uncus is usually simple, digitate, the saccus
broad, shallow, rounded. The valve costa has angled, spine-like or digitate
processes, often at its distal end. Many species have a pair of processes
arising from the base of each valve. A tuft or greater concentration of
hair-setae is often present at the centre of the ventral margin of the valve.
The female genitalia provide what is probably the most reliable
diagnostic character of the genus: between one and three rows of slender spines
that arc or spiral longitudinally in the bursa.
Bell (MS) described the larvae of two S. Indian Ozola. They are
cylindrical, tapering slightly towards the head, rounded in one species,
squarish in the other. The surface of the body is dull with transverse folds,
the setae short, erect, on minute tubercles. The colour is marbled grey in both
species. See also O. minor Moore below.
The pupa is cylindrical, slender. The appendages do not extend beyond
the end of the wings, though the portion from the front of the pupa to this
point is exceptionally long. The cremaster in one species, O. extersaria Walker,
is disc-like, bearing a fan of four fine, hair-like, hooked shafts.
The larva of extersaria rests at 45 degrees from the
substrate surface (usually the edge of a leaf), the thorax slightly kinked in
the vertical plane. It will fall suspended on a silken thread when disturbed,
sometimes twisting like a snake. The other species (identified as O.
leptogonia Hampson, a synonym of O. minor Moore, but no vouchers have
been located to confirm this), lives on the underside of the tender leaves of
the host-plant, sitting mostly highly looped or sometimes stretched out
straight, the thoracic legs held clear of the substrate.
Pupation is in a silken cell, sometimes incorporating particles, on the
ground, in a dead leaf or a dark crevice. The adult has a weak flight, tending
to rest on tree trunks or the underside of leaves.
The host-plant of O. extersaria is Premna and that of O.
leptogonia is Gmelina, both Verbenaceae. Singh (1953) recorded
O. microniaria Walker from Premna, and O. minor Moore has
also been recorded from this host in the Andamans and from Gmelina in
Borneo (see below). Therefore the genus would appear to be specialist on
arboreal Verbenaceae.
Bornean species fall into two or more groups. The first five listed have
simple valves with a slender apical or subapical spine to the valve costa. The
remainder have a pair of processes at the base of each valve and include a
subgroup of five dark grey and white montane species. The genus is diverse
throughout the Indo-Australian tropics and is represented by a single species on
New Caledonia. It also occurs in Africa and the Arabian Peninsula.
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