Spatial dynamics of teak defoliator (Hyblaea puera Cramer) - Cochin ...

6.3.4. Oviposition
Egg-laying was found to start at dusk (6.55 p.m. to 7.10 p.m.) on all the
three days observed. The females hover over the shoot for a while and settle on
the leaves. Eventhough some moths settled on the older leaves, they moved on to
the lower surface of nearby tender foliage. The female moth walks on the leaf
with the tip of the abdomen touching the leaf surface. The moth lays a single egg
at a time close to the veins of the leaf. Moths were found to oviposit on leaves
which was oviposited earlier.
On the first day of observation, there were 372 eggs in the 56 leaf pairs
tagged. On the second day, the number ofeggs increased to 619. On the third day,
a total of 750 eggs and 93 first instar larvae were found. There were no further
additions on subsequent days. It can be seen that the maximum number of eggs
was laid on the first day. On the second and third days, the numbers of eggs laid
were almost equal- 269 and 268 respectively. Observations on 56 leaf pairs
concluded that egg-laying can happen on the same leaf for at least three
consecutive days. The population ofmoths that laid eggs on all the three days can
either be the same group of moths arriving each day from a place of aggregation
or different groups ofmoths.
6.4. DISCUSSION
Cage observations confirmed the earlier known information on pre-mating
period. The characteristic calling behaviour of the moths could be observed in the
cage, which could notbe seen in the earlier laboratory studies. Observations made
outside the cage gave new information on one of the most mortality prone life
stage of the insect- the time immediately following adult emergence from the
pupa. Attraction of birds to the emergence site suggests that they are responding
to some cue, possibly scent emanating during adult eclosion.
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