Some Alternative Pest Control Methods
Integrated Pest Management (IPM) considers both crops and pests as part of an
ecological system and combines natural factors that limit pest outbreaks while using
insecticides as a last resort. In most situations where insects are a problem, some form
of IPM is now considered to be the most appropriate approach to their control.
Rotenone, a natural product extracted from the roots, seeds and leaves of certain
tropical legumes such as Derris, is commonly used as a safe form of insect control.
Another example of biocontrol is the Trichogramma—the larvae of which eat insect pest
eggs. Further information on biological control of pests is available on the Wikipedia
website and elsewhere.
When it has been decided that insects are causing economic damage, or they are
liable to do so, there are a number of solutions which can be adopted on a small scale
which avoid the need to use expensive and potentially lethal insecticides:
Biological Ladybirds, chalcid flies and fungi can be encouraged to combat
aphids and others.
Nicotine Either in the form of home-grown tobacco or cigarette ends nicotine
can be an effective remedy for insects such as aphids, scale insects,
weevils, caterpillars and leaf miners. The nicotine mixture is made by
soaking tobacco leaves and/or butts of cigarettes in water for some
days. Unfortunately this is a powerful insecticide which may also kill
harmless or useful insects (and do no favours to the gardener).
Trap Crops Crops such as onions can be useful in deterring insects from
damaging other crops. This method of insect control is discussed in
and also “green bridge volunteers” should be eliminated.
Neem Tree This large tropical tree, Azadirachta indica, also known as Nim, or
Margosa, can be used as a safe, natural and free insecticide,
especially when mosquitoes and malaria are prevalent. Sometimes the
dried leaves are burned inside storage containers and buildings to
deter insect infestation. Details are available online from “One Tree’s
Arsenal Against Pests”.
Pyrethrum This is a botanical insecticide, mainly produced in the flowers of a
perennial herb, Chrysanthemum cinerariaefolium, which contain
pyrethrins, used as a safe and effective insecticide.
Soap & Water On a small scale this can be used to deter insects such as aphids, and
also to give some protection to the plants that have been sprayed,
until the next rain.
Timing A minimum interval of time between ploughing and planting reduces
the risk of pest survival (eg. six weeks for Frit fly).
Insect Resurgence
When persistent organophosphate insecticides are used against a certain insect pest very
often the natural enemies, the predators, of that insect are also killed. Subsequently the
80 TONY WINCH
1Ge. “Companion Crops”, page 63. Alternate hosts for the insects,