Behavioral manipulation of insects with spice-based
deterrents may provide an alternative control strategy.
Microencapsulation technology could lead to more effective
use of spice essential oils and oleoresins in the field by
extending their residual activity. The feeding and oviposition
deterrent potential of the microencapsulated cardamom
(
Elettaria cardamomum
[L.] Maton) oleoresin (MEC-C)
and eucalyptol (MEC-E) were evaluated against codling
moth,
Cydia pomonella
Linnaeus, 1758. MEC-C capsules
contained both 1,8-cineole and α-terpinyl acetate, whereas
MEC-E capsules contained only 1,8-cineole. In larval
feeding bioassays, MEC-E exhibited the lowest feeding
deterrent activity (33%) while MEC-C at 100 mg mL
-1
had the highest (91%). The highest oviposition deterrence
activity against gravid females was also shown by MEC-C
at 100 mg mL
-1 with 84% effective repellency. In 2010
and 2011, two apple orchards were divided into four 1 ha
blocks and sprayed with the following treatments in ultralow
volume sprays: (a) MEC-E at 100 g L
-1, (b) MEC-C at
50 g L
-1, (c) MEC-C at 100 g L
-1, and (d) MEC-pyrethrin
at 15 mL L
-1. Water-treated abandoned orchards were used
as negative controls. Moth catches were monitored weekly
using Ajar traps baited with the combination of codlemone,
pear ester, and terpinyl acetate. Based on pooled data, mean
cumulative moth catch per trap per week was significantly
higher in the MEC-E blocks (26.3 male and 13.5 female
moths) than those in other treatments except the abandoned
blocks. At mid-season and pre-harvest damage assessment,
the percentage of infested fruits with live larvae in the high
dose MEC-C-treated blocks was reduced to 1.9% and 2.3%
in 2010 and to 1.1% and 1.8% in 2011, respectively. Since
fruit damage exceeded the economic damage threshold
of 1%, high-dose MEC-C treatment may only offer
supplementary protection against codling moth in integrated
pest management programs.
