Molecular Characterization and Management of Shoot and Fruit Borer Conogethes ... 221
could complete the life cycle on the three types of
castor and cardamom. The insect required longer
period (in days) of time to complete the life cycle
on cardamom than on castor, i.e., on an average
34.5 days on castor compared to 39 days on car-
damom (Doddabasappa 2012 ).
When Conogethes reared on cardamom were
implanted on castor, larvae suffered cent percent
mortality. Besides, larvae completed the period
early probably because of physiological stress
throughout by host plant shift (11–12 days).
When castor larvae were on castor itself, larvae
took 14–16 days. This is the normal larval period
and larvae did not suffer from any mortality.
When Conogethes reared on castor were im-
planted on cardamom, larvae suffered cent per-
cent mortality. Larvae completed the period early
probably because of physiological stress brought
out by host plant shift (13–14 days). When car-
damom larvae were implanted on cardamom,
larvae took 20–22 days. This is the normal larval
period and larvae did not suffer from mortality.
The drastic reduction in survival of the larvae,
pupae, and insect as a whole may be attributed
mainly to antibiotic factors. Antixenosis in com-
bination with antibiosis might play a role in re-
duced pest survival. The antibiotic factors in
terms of antimetabolites/antidigestible chemical
components and antixenosis in terms of presence
of trichome on castor types may impede larval
movement on the host, the spines inhibited con-
sumption of the host material. It is interesting to
record here that the mortality of neonate larvae
recorded was much higher compared with the
later instar larvae (Doddabasappa 2012 ). Davis
et al. (1989) too found reduced larval survival
and larval weight of southwestern corn borer,
Diatraea grandisella Dyar with increased devel-
opment time when larvae were fed on whorl leaf
tissue from resistant genotype. Resistance was
identified as a combination of larval nonprefer-
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WKDQFDSVXOHA flow chart showing pattern of Conogethes infestation on castor and cardamom (Doddabasappa 2012)