222 P. R. Shashank et al.
Consideration of the sequential behavioral steps
in host selection raises a number of issues that
have consequences for host specificity testing.
Much of the progress in applying the concepts
of insect behavior to host specificity testing has
been made by examining this process (Wapshere
1989 ; Marohasy 1998 ). Possibly, the most im-
portant consequences are those that stem from
the absence of early steps in the host selection
sequence in experimental arenas. To find wheth-
er Conogethes populations sustaining on castor
and cardamom are genetically homogenous,
studies on the host shift involving two afore-
said plants were conducted. Results showed that
the Conogethes originating from castor could
not survive on cardamom and vice versa. Lar-
vae suffered 100 % mortality when fed on cas-
tor and cardamom after host shift. The reduced
plant consumption and subsequent reduced lar-
val survival may also be due to Hopkins’ host-
selection principle (HHSP). HHSP refers to the
observation that many adult insects demonstrate
a preference for the host species on which they
themselves developed as larvae. Although the
practicality of HHSP has been debated signifi-
cantly since its first proposal in 1916, in the case
of Conogethes a cent percent mortality of insects
was recorded and not even a single insect com-
pleted the life cycle normally (Hopkins 1917 ).
This suggest that, although there is an effect of
host shift, but the entire impact on the life his-
tory of insect is not due to the HHSP but in a
major way due to the unsuitability of the plant as
a food source for the candidate species (Dodda-
basappa 2012 ).
When nonhost plant like Ocimum was offered
to these Conogethes larvae, none of the larvae
orientated and none of them showed initial bit-
ing responses. This observation suggested that on
the same host higher number of larvae oriented
toward and moderate number of larvae orientated
toward plants related to Conogethes species to the
host plant and none of the larvae showed orien-
tation and biting responses on the nonhost plant
(Table 4 ).Host selection is influenced primarily
by moth oviposition, but neonate ballooning and
larval movement also are important (Ross and
Ostlie 1990 ). Learning about feeding preferenc-
es of the neonates for different plant hosts will
help decipher complex plant–insect interactions
in different cultivated ecosystems and may help
predict the degree of Conogethes infestations in
natural and cultivated ecosystems.Quarantine importance
The distribution of C. punctiferalis extend from
Asia to Australia (CABI 2011), representing a
complex species (Robinson et al. 1994). Accord-
ing to the unpublished reports of the Food and
Environment Research Agency (FERA, UK) lar-
vae of C. punctiferalis have been detected inside
tropical fruits 18 times in the last 5 years at three
points (in England and Wales) between 2007 and- Due to report of damage to apples in North
China (CABI 2011), interceptions of the pest in
fruits from Pakistan, and a pest concern to many
countries like New Zealand, South Africa, Cana-
da, and the USA, a Rapid Pest Risk Analysis on
Conogethes was conducted.
Since the members of species within the com-
plex are unknown and their biology cannot be
distinguished, Conogethes represent all the more
important species from quarantine point of view.
So the Pest Risk Analysis (PRA) assessment has
Table 4 Behavioural responses of Conogethes to host and shifted host plants. (Doddabasappa 2012 )
Attribute Host plant Shifted plant
Movement Direct (taxis) Random (Kinesis)
Time budgeting Less for movements, more for feeding Negligible or Very less for feeding
Energetics Normal growth and development Abnormal, highly reduced
Establishment on plant Occured Does not occur
As food source Suitable Unsuitable
Feeding behavior of larvae Normal Deviate from the normal
Ovipositional behavior of moths Normal Deviate from the normal