Fumigant Toxicity of Nutmeg Seed Essential Oil ( Myristica fragrans Houtt.) ... 131
This research showed that the essential oil of
nutmeg seeds is of good quality as it has ideal per-
centages of essential oil and active compounds.
The standard of Materia Medica Indonesia (MMI)
requires that the essential oil content in nutmeg
seeds be 5–10 %, and it was found to be 6.85 % in
this study. Additionally, the content of myristicin
and safrole measured in this study exceeded MMI
requirements of 5–10 %. M. fragrans oil showed
strong fumigant activity against C. maculates
adults at different concentrations and exposure
times. In all of the concentrations, the oil yielded
more than 90 % mortality after 12 h, so the effec-
tive time for mortality could be 12 h.
Concentration of 30 μL/L in air and exposure
time of 24 h were enough to obtain 100 % kill of
the insects. At the lowest concentration, the oil
yielded nearly more than 50 % after 9 h against
C. maculates. Probit analysis showed that for this
essential oil the LC 50 is 4.232 and LC 95 is 19.158
(Table 2 ).
This is the first report on the insecticidal activ-
ity of M. fragrans in the world. It has been rec-
ognized that plant-derived insect-control agents
could be developed into products suitable for
integrated pest management because they are
selective to pests, have no or little harmful ef-
fect against nontarget organisms or the environ-
ment (Arnason et al. 1989 ; Schmutterer 1992 ;
Hedin et al. 1997 ; Isman 2000 ). The essential oil
extracted from Myristaceae family has shown
strong effect on stored-product insects such as
C. maculates. In this study, the fumigant activity
of M. fragrans was attributed especially to sabi-
nene, 4-terpineol and myristicin as major con-
stituents of the oil.
In this study, M. fragrans was characterized
by a rapid knockdown effect, hyperactivity, con-
vulsion and paralysis and dead. These effects
show that this essential oil could act like tradi-
tional fumigants. M. fragrans naturally produce
many volatile compounds that are not only im-
portant for aromatic and flavor characteristics,
but also have the additional benefit of offering
for the management of stored-product pests.
Therefore, essential oil of M. fragrans could
have potential as an alternative to methyl bro-
mide for postharvest control of insect pests in
storage. Regardless of potent activity of essential
oils as fumigants, however, there are several bar-
riers to commercialization for botanical insecti-
cides including availability of sufficient quanti-
ties of plant material to produce the pesticides,
the standardization and refinement of pesticide
products. While some essential oils are currently
available in large quantities, essential oils from
rare plants may be difficult to obtain in sufficient
quantities (Isman et al. 2007 ).
It may be possible to produce botanical in-
secticides by phytopharming through genetic
engineering of an existing field crop to produce
high-value natural products. Due to rapid volatil-
ization and low persistence of the essential oils
in the environment, it is unlikely to use them in
field crops; however, this property is conductive
to use them in stored-product pest-controlled
conditions.
The insecticidal constituents of many plant
extracts and essential oils are monoterpenoids.
Due to their high volatility, they have fumigant
activity that might be of importance for control-
ling stored-product insects (Coats et al. 1991 ;
Konstantopoulou et al. 1992 ; Regnault-Roger
and Hamraoui 1995 ; Ahn et al. 1998 ).
In general, the longer insects are exposed to
a fumigant, the lower the dose that is required to
control insects. The rate of decline is described
by the concentration-time (CT) product; concen-
tration, usually the LD 50 or the LD 95 , multiplied
by time. For some fumigants, such as methylTable 2 Fumigant toxicity of M. fragrans essential oil against C. maculates
Insect species LC 50 LC 95 Slope ± SE Degrees of freedom
Chi-square
C. maculates 4.232 19.158 2.72 ± 0.26 6
6.502
(3.52–4.81) (13.09–32.28)
Units LC 50 and LC 95 = μL/L, applied for 24 h at 27 °C; 95 % lower and upper fiducial limits are shown in parenthesis