Impact of - IDL-BNC @ IDRC - International Development Research ...

Africa and now East Africa. The success in West Africa is touted as one of the
untold stories of biocontrol.
Leucaena psyllid
Leucaena leucocephala, a tree much used in agroforestry for fodder, fuel, green
manure, and soil conservation in Asia has been decimated by the psyllid,
Heterapsyfla cubana, which moved from Latin America through Florida,
Hawaii, the Pacific Islands, Australia, Indonesia, and the Philippines, finally
reaching India and Sri Lanka through aircraft and high altitude currents from
1983 to 1988.
Two parasitoids and a generalized cochinellid are being evaluated for use
against this pest. Some have been introduced unofficially into Southeast Asia
without appropriate quarantine. There is some concern over the possibility of
introducing a damaging fungus and that the generalized predator may interfere
with a weed-control program on mimosa. This has raised the issue of
"prior informed consent" (PLC) and governments and quarantine authorities
are aware of risks and potential conflicts of interest.
Personnel on these projects work closely with the Commonwealth Institute of
Biological Control (CIBC). Its role has been to assist in the survey for potential
controls, taxonomy, determination of efficacy, rearing methods, and thirdcountry
quarantine.
Inundative releases
China has used Trichogramma wasps, which are egg parasites of many pests.
Tr-ichogramtna dendrolimi and T. chilonis have been used successfully to control
sugarcane borers in southern China. The estimated cost of biocontrol is
16.50 USD/ha, about 10% of the cost of the previously used chemical control.
Moreover, control is better and health problems are much reduced.
Trichogramma has also been used for control of Asian corn borer on 13 000 ha
of Beijing watershed that were formerly sprayed with DDT.
IDRC support in China has helped to develop rearing techniques for large and
small eggs and artificial rearing, to carry out ecological studies on other
species, and to expand the use of these methods to other crop pests. A book in
Chinese and English summarizing the Chinese experience is in preparation
and training is planned for 1992. This project involves the collaboration of
researchers at Guelph University, who are carrying out research on rearing,
storage, and pheromones and assisting in training.
Microbial control
In India, a survey of local microspodia (Nosema sp.) has been completed; the
organism has been cultured and shown to be effective against grasshopper
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