376 A. D. N. T. Kumara et al.
The augmentative releases of parasitiods,
Trichogramma minimum Riley, Goniozus ne-
phantidis Muesebeck and Bracon brevicornis
Wesmeal, are all known parasitoids of the spe-
cies, and work by parasitizing larvae at different
instars (Venkatesan et al. 2009 ). G. nephantidis
and B. brevicornis both parasitoid wasps, parasit-
ize third to seventh instar larvae, leading to the
eventual shriveling and death of the organism.
Wasps have been observed parasitizing up to
57 % of the resident larvae, which would reduce
the population of the BHC significantly. While
G. nephantidis proves to be the dominant parasit-
izing species over B. brevicornis due to more de-
veloped parental care in B. brevicornis and there-
fore reduced number of parasitization, they both
act as effective species in controlling the coconut
BHC (Venkatesan et al. 2009 ).
Use of Pheromone
The presence of female sex pheromone in the
BHC has been revealed from studies in Sri Lanka
and India (Murthy et al. 1995 ). Studies were
conducted to ascertain the attraction of virgin
females of the BHC to conspecific males. One-
to two-day-old virgin females were individu-
ally confined in net cages and fixed to the sticky
traps. The traps were placed horizontally in the
canopy of the infested palms for two consecu-
tive nights. The results indicated that the number
of male moths trapped in baited traps was sig-
nificantly higher than in unbaited traps. Hence,
the results revealed the attractiveness of virgin
females to conspecific males of O. arenosella
due female sex pheromone released from caged
virgin females (Fernando and Chandrasir 1997 ).
Work conducted in the 1980s by the Natural
Resource Institute using insects from Sri Lanka
demonstrated the presence of four electro-physi-
ologically active compounds in extracts from fe-
male moths (Cork and Hall, 1998 ). The putative
pheromone components were identified and field
tested in Sri Lanka but high catches in unbaited
traps hampered the field work (Cork and Hall
1998 ).
Srinivasa and Muralimohan (2009) expressed
the scope for utilizing sex pheromones for the
management of O. arenosella. The behavioral
attributes like that the adults emerge restricted
to 10–15 days over 30 successive days in a gen-
eration, that populations are protandrous, and
the reproductive biology of O. arenosella shows
less probability of trapping an unmated male in
mass trapping. Further, they suggested that the
sex pheromones can directly contribute toward
downsizing populations of O. arenosella if they
are used for disrupting natural mating.
Female-produced sex pheromone (Z, Z,Z)
3,6,9-Tricosatriene released by the female was
identified, artificially synthesized, and field-
tested in India (Bhanu et al. 2009 ). Bhanu et al.
( 2011 ) made an attempt of GC-MS analyses of
volatiles collected from virgin females. O. are-
nosella confirmed the structure of the O. areno-
sella pheromone as (Z, Z,Z)-3,6,9-tricosatriene
(Z3Z6Z9–23Hy). Further, field trials indicated
that using wing traps PVC vial dispensers with
100 μg, the pheromone loading was significantly
superior in attracting the male moths. The trap
catches of the BHC male moths in ten phero-
mone traps were able to indicate moth emergence
peaks.