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LEPIDOPTERA, Cyclotorinidae -- <Images> & <Juveniles> The Australian Cyclotorna
monocetra Meyr. and other Cyclotorna spp. show a remarkable
adaptation for feeding. Young larvae
are parasitic or predaceous on Cicadellidae, while later stages feed entirely
on body fluids of ant larvae (Dodd 1912).
This obligatory change of food at an intermediate point in the larval
period was considered most unusual, especially as it seems to subject the
species to considerable hazard (Clausen 1940). The larvae are also dependent on the ants themselves in order
to gain access to the nest. Female moths lay their eggs in large numbers on the twigs in the
vicinity of leafhopper colonies. On
Hatching, young larvae move about until a prey is found, after which they attach
themselves and begin feeding. They
change position on the host body somewhat, but later are found primarily on
the abdomen. If wing pads are
developed on the host, feeding is usually beneath one, which is as a result
forced out of its normal position.
One to 8 larvae may be found on a single leafhopper, and a silken web,
extended at one side to form a delicate wall, is formed underneath the
host. A portion of hosts probably
dies without reaching the adult stage.
The cyclotorinid larvae sometimes move from one host to another, and
thus they are best considered predators with considerable advancement toward
obligate parasitism. The larvae leave their leafhopper hosts before completing the
first instar. They construct a light,
oval and flat cocoon within which the first molt occurs. Second instar larvae emerge from this
cocoon 3 days later to move a short distance away. Then they assume a peculiar attitude, with both ends of the
body raised so that they almost meet over the dorsum. When mound ants, Iriodomyrmex purpureus Smith, find these larvae they are quickly
seized and carried into the nest.
Here they feed on the body fluids of the ant larvae and at the same
time provide food for the ants through their secretions. When growth is complete, the larvae leave
the ant nest and ascend a tree nearby, where they spin cocoons in crevices of
bark, etc. At adult emergence, the
pupal skin remains partly extruded from the mouth of the cocoon, and the
pupal stage takes 19-20 days (Clausen 1940/1962). The oblong eggs are very tiny and bear pronounced longitudinal
striations. First instar larvae are
oval and quite flat, with a median longitudinal ridge. They are at first a dull yellow but later
become pink. There are no large
differences between early 2nd instar and mature larvae. They b ear a close resemblance to
woodlice. The body of the 2nd instar
larva is very flat and oval, with a distinct median dorsal ridge. Each segment has at its lateral margin a
fleshy pointed projection. Those on
the last segment are produced into a pair of tail-like processes about as
long as the body. The initial color
is orange-red dorsally and white ventrally, which changes to pink and
greenish-blue or blue, the coloration being due to the body contents showing
through the transparent integument.
Larvae of C. experta Meyr. do not have the lateral
and caudal processes (Clausen 1940/1962). References: Please refer
to <biology.ref.htm>, [Additional
references may be found at: MELVYL Library ] |