Plants with Pest Control Properties Against Urban Pests - Urban Insect Pests: Sustainable Management Strategies - page 229

A second factor against the popularity of
natural products is the expectation that
plant-based chemicals will behave and
possess properties in line with synthetic
ones. Properties such as availability, affect-
ing multiple pests and persistence in the
site of application are lacking with natural
compounds. Additionally, natural extracts
need purifi cation before being approved for
use because they contain a cocktail of many
compounds that could present unknown
hazards. As an example, cedar leaf oil (CLO)
from Juniperus virginiana has excellent
anti-termite properties but it is also known
to contain significant amounts of saffrole, a
suspected carcinogen (Comer et al ., 1982).
Thus the presence of saffrole in the leaf oil
may limit the potential uses or require its
removal prior to use, making the oil either
unusable or expensive if it is to be used in
purifi ed form.
It is notable that traditionally known
natural products are in decline and existing
ones are being phased out by regulatory
authorities (Arnason et al. , 2012). In 2008,
US EPA received a request to cancel the
registration of the last nicotine pesticide
registered in the USA owing to issues
related to toxicity (US EPA, 2012). This
request was granted and in 2014 nicotine
will not be available for sale (US EPA,
2012). Also in the USA and Canada, all uses
of rotenone except as a piscicide are being
phased out (US EPA, 2012). On the other
hand, the use of pyrethrum and pyrethrins
is increasing in global surveys. In addition,
essential-oil-based products have recently
emerged as the most important botanical

insecticides. Recent research has also
demonstrated the potential of a number of
plant-based compounds including piper-
amides, acetogenins, thiophenes and limo-
noids (Arnason, et al. , 2012). Thus the
future of natural products will depend on
the identifi cation of newer compounds
from plants and designing synthetic
techniques to produce them for commercial
usage.
The potential for the use of natural
products in urban pest management is
slowly being realized and it could gain
signifi cance in future. Indeed, the practice
of integrated pest management (IPM) pro-
vides more scope for its inclusion. Though
it is known that plant-based products could
not serve as a stand-alone systems, they can,
however, supplement and at times substitute
conventional pesticides in pest control
programmes, such as on maintenance jobs.
Overall the success of these products would
largely depend on the success of IPM.
Natural products could also play a role
away from conventional uses as a pesticide,
such as in wood preservation. Wood
preservation is a large industry and there is
great potential for using natural products as
wood preservatives. Research has found
that extracts from eastern red cedar heart-
wood as well as from needles can be
impregnated into wood to impart resistance
against termites and wood-rot fungi. Cedars
are an abundant under-utilized resource
that could provide a renewable source of
natural wood preservative materials and
meet consumer demand for safe products
(Eller et al. , 2010).

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