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CULTURAL PEST
CONTROL METHODS Cultural control
may be important in many pest control strategies. The section on
"Environmental Management" treats of this in some detail. For
example, the effective environment of an organism has been characterized by
Rabb et al (1976) as weather, food, habitat (shelter, nests) and other
organisms. Environmental management for biological control is concerned with
the functional environment, i.e., the physical and biotic elements that
directly or indirectly impact survival, migration, reproduction, feeding and
the behaviors associated with these life processes. Although pest populations
can be controlled directly through cultural control methods that modify the
habitat, the main thrust of this section is conservation (maintenance of
natural enemy abundance and diversity) and enhancement (increased
immigration, tenure time, longevity, fertility and efficiency) strategies
that can be used to manipulate natural enemies in agroecosystems. Habitat
management is directed at (1) enhancing habitat suitability for immigration
and host finding, (2) providing alternative prey/hosts during times when
pests are scarce, (3) providing supplementary food (food sprays, nectar and
pollen for predators/parasitoids), (4) maintenance of non economic levels of
the pest or alternative hosts over long periods to ensure continued survival
of natural enemies and (5) providing refugia for mating or overwintering.
Cropping Techniques that enhance parasitoids through these five processes have
been reviewed by Powell (1986) and shown in table form by Altieri &
Letourneau (1996). Approaches to
manipulating natural enemies include several levels, from agroecosystem
processes to eco-physiological features of individual organisms. The number
of elements that can be manipulated and their degree of flexibility depend on
characteristics of the agroecosystem. The role, methods and future directions
of environmental management as a preventative control strategy are detailed
after Vandermeer & Andow (1986) in the following sections. A notable case
is the successful cultural control of houseflies that breed in decaying
melons in the American Southwest (Legner & Olton 1975, Olton
& Legner 1973). The
simple procedure of breaking-open culled melons at harvest accelerated decay
of the breeding source and greatly reduced fly breeding. Another example is the elimination of
breeding sites for the Australian bush fly, Musca sorbens, in the
Marshall Islands by reducing the number of unleashed dogs on the islands as
well as the institution of an effective adult fly baiting procedure (Legner
et al 1974. ) REFERENCES Please see <bc-58.htm> for greater
detail) [Additional references
may be found at MELVYL
Library ] |