and Integrated Pest Management - part - usaid

208 PESTICIDE MANAGI-2.MENT AND HPM IN SOU111EAST ASIA
impossible to Choose other alternatives. The decision makers relied on broadspectrum
insecticides and thought that pest control was just another short-term
and straight lorward problem. So they searched for a simple answer, i.e., total
reliance on broad-spectrum and persistent insecticides.
The results obtained were similar to those throughout the world where
broad-spectruin insecticides were used. Outbreaks occurred inmany places. The
pesLs resurged in shorter time. Many secondary pesLs appeared and caused serious
losses. To make matters worse, no one bothered to ask whether complete
reliance on broad-spcctwum insecticides was an intelligent policy.
Indonesia stopped the use of*broad-spectrnm and contact organochlorines in
1970, while Malaysia did so eight years earlier (Wood 1971). Organochlorines
were replaced by other insecticides, like orgaliophosphates, carbamates and
synthetic pyrethroids. Outbreaks or small population explosions still occurred,
but less frequently. The breathing spell allowed time to study ways to improve
the use of insecticides and to find other alternative measures.
Spraying Tcchnique
In the past, entire infested areas were spraycd thoroughly whenever spraying
was done, regardless of the extent of damage, pest distribution, or environmental
condition. Naturally this kind of spraying consumes a large amount of
insecticide, little of which is deposited on pkilns or target insects. Spot spraying
is now suggested. Blanket spraying is reserved only for treatment of outbreaks,
or if the inl'estation in an area is very high.
Early Warning and Critical Levels
As much as possible, pest attack must be detected at the inception stage.
An Early Warning System is developed through improvement in the population
cCnsus system. Mapping the attack is a good practice, since it is a very useful
factor for deciding whether or not to make an insecticidal treatment (Djamin &
Sipayung 1986).
Often, a critical level of pest population is used as the sole factor in deciding
whether a chemical treatment is necessary or not. In reality, it should be viewed
as just one of the factors in decision making, besides information on pest
biology, presence of natural enemies and environmental factors (Djamin &
Sipayung 1986). In practice, there are many problems faced by the crew during
census work, e.g., entomological knowledge of the census crew, height of the
trees, determination of the sample frond, etc. These problems greatly influence
tie accuracy of data collected.
Seleclivity of Insecticides
Selectivity is one important factor to consider when using an insecticide.
For example, trichlorfon is a selective insecticide in the oil paim ecosystem. It
is an effective insecticide against bagworms, is safe for their natural enemies, and
has been used many times with satisfactory results. Wood (1971) reported that