Biology Reference
In-Depth Information
lantana under fi eld conditions has not yet been
measured, and a community-based trial to
measure the infl uence of lantana on the
mosquitoes and clinical outcomes would be
necessary to measure such a potential ef ect.
promising insecticide, especially now that it has
been synthesized and can be commercially
produced at consistent quality at lower prices.
The neem tree continues to provide
solutions to development not only as a form of
pest control, but also with added values such as
soil protection and shade. It is these multiple
uses of plants along with their sustainability, on
top of the increasing cost of production of
petroleum-based compounds such as DEET, that
may see an increase in the reliance of botanical
means of insect control and insect bite
prevention in the future. It is important that the
production of pest control and other health
products becomes decentralized and focused
where they are needed. The abundance of
phytochemicals found in tropical plants may
mean that in the future, production and
manufacture of plant-based means of disease
control can become a real feature of sustainable
development, providing a means of income to
rural farmers in the tropics and solutions to
current insect-borne diseases. It is important
that research into phytochemicals moves with
the times and the recent publications using
novel techniques and robust testing
methodologies are certainly a cause for
optimism. Furthermore, novel strategies such as
environmental management of mosquito sugar
resources have great promise.
All environmental control methods of
disease vectors utilizing plants are highly
dependent on the species- and site-specifi c
ecological requirements of dif erent insects,
which are still mainly under-researched. There
is large scope to investigate the natural
behaviours and environmental habitats of
disease vectors, not just to improve knowledge of
disease ecology but also to design more ef ective
control programmes. Manipulating the natural
habitat can have unforeseen side-ef ects, and
great care must be taken to minimize the impact
on non-target species as well as the local
communities. Also, before new control practices
are implemented, the secondary economic and
social benefi ts and incentives for the local
community must be considered; without their
support, no successful, self-sustaining vector
control project will be able to function.
4.3 Conclusions
Plants have been used in traditional practices,
including hanging bruised plants outside the
house or burning plant material, for thousands
of years to kill and deter insects that cause
nuisance, disease and threaten crops. They have
been used very successfully and synthetic
pyrethroids, derived from the pyrethrins, have
saved millions of lives through their use in
vector-borne disease control. However, natural
does not necessarily equate to safe (e.g. Section
4.1.2), and toxicity tests must be performed and
environmental care must be taken when
considering plant-based control agents. Modern
plant-derived products available on the market
today that are approved by WHO and EPA have
been through rigorous safety and ei cacy testing
and it is important that consumers are aware of
the need for such endorsements to dif erentiate
those products documented as safe and ef ective
for disease prevention from untested natural
products. The demand for plant-derived
repellents and insecticides is increasing as
consumers want sustainable products that are
pleasant to use. Careful sourcing of tropical
plant-based products such as citronella or PMD
that are ethically produced with care for the
environment and the producers are undoubtedly
a positive consumer choice and should be
encouraged.
In the past 20 years, a novel insect repellent,
piperadine, has been developed based upon a
molecular framework found in the pepper family
and now other chemicals isolated from this
family may provide the means of ef ective larval
control to combat globally important diseases
such as dengue. The identifi cation of plant-based
molecules that target cholesterol metabolism
provides a new avenue of research into
insecticides with very low non-target toxicity.
Azidirachtin from the neem tree is another
Search WWH ::
Custom Search