and Integrated Pest Management - part - usaid

274 PESICDE MANAG-MENT AND 11M IN SOUTILEAST ASIA
1984); c) by using selective pesticides with relatively short persistency; d) by
using novel chemicals (Tan 1976, Tan & Loke 1984), or non-chemical methods
where possible as supplementary methods when they are cost-effective; and e) by
using sub-lethal doses of pesticides which have known antifeeding (Tan 198 1b),
or irritancy effects (Tan 1982).
Alternative Pesticides and Control Methods
When pesticide resistance affects operational economics, the search for an
alternative pesticide or control method is inevitable. In the search for an
alternative pesticide, the mechanism of resistance of the target species should be
studied. Reference to experience gained by studies of different types of
resistances, patterns of cross or multiple resistance and interaction of resistance
mechanisms in other species should be taken into account for selecting the
prospective pesticides. Then field selection trials should be conducted to select
suitable alternative pesticides. In the case of P. xylostella, in which multiple
resistance has probably developed, a good alternative pesticide would be a
microbial insecticide (Sivaprasagam 1983, Sivaprasagam et al. 1984), or an
insect growth regulator, especially one that inhibits chitin synthesis (Tan 1981a,
Tan & Loke 1984). The use of natural enemies (Ooi 1981) may be considered as
an alternative control method.
In view of possible resistance problems, hazardous effects and environmental
contaminatior, that may arise through widespread application of pesticides, plus
the inevitable use of certain pesticides for animal and plant protection in the
foreseeable future (Lim & Heong 1984), an ecological approach to pest control,
particularly for insect pests, is probably the soundest and safest approach and
should be encouraged (Tan et al. 1982). There is, however, an important role for
pesticides when used judiciously within the context of an integrated pest control
(IPC) program. Nevertheless, the implementation of an IPC program in
Malaysia has its constraints (Lim et al. 1981, Lim & Ooi 1984), which can be
overcome by careful studies and planning by researchers together with proper
coordination and cooperation of tie agencies involved.
RECOMMENDATIONS AND CONCLUDING REMARKS
The problems related to pesticide resistance in Malaysia are many. Some
problems may be dealt with at the institutional or national level, and others
through international cooperation especially at the regional level within
Southeast Asia with assistance and funding from international organizations. It
is therefore recommended that:
1. In view of the importance of accurate and reliable data on pest resistance,
susceptibility tests should be conducted by trained staff. Results of these
studies should then be forwarded promptly to a central coordinating national
agency or institution.
2. Information on all aspects of resistance for any species and any country
should be compiied and distributed.
3. A national insecticide reference laboratory should be established to