Aerial baiting to control leaf-cutting ants (Formicidae, Attini) in Trinidad. III. Economic implications

Abstract

AbstractThe losses caused by leaf-cutting ants (Acromyrmex octospinosus (Reich) and Atta cephalotes (L.)) to citrus and cocoa crops in Trinidad were assessed as about $40 000 TT per annum in each of these crops. Losses to other crops were unassessable on a national scale but often important to individual farmers. Aerial baiting, using a locally produced bait of aldrin, soyabean oil and citrus meal, would be at least as, and probably more, effective than current on-farm control methods. The cost was $6.18/ha, approximately four times cheaper than current methods and twice as cheap as searching for nests and applying the same bait to them by hand. Hand baiting with the local bait would be almost twice as cheap as using the imported alternative available. At the dosages and frequency of application recommended (2.2 kg of bait containing 0.4% technical aldrin/ha/annum) the total amount of organochlorine insecticide currently used against leaf-cutting ants in Trinidad would decrease between two- and ten-fold, depending on the area treated. Serious long term residual effects are most unlikely to develop, and if bait were applied carefully no harmful effects to man or stock would occur. Farms larger than four hectares would benefit proportionately more than smaller farms, unless charges were manipulated. Fewer men would be needed to control ants than at present. Losses to traders caused by a decrease in the sales of alternative insecticides would be trivial. A national dry-season baiting scheme would utilize more fully aircraft already available in Trinidad, and would help export crops and the production of home-grown foods.