Control of the Mexican Fruit Fly by Bait Sprays Concentrated at Discrete Locations

when a bait spray (a 1:4 mixture of 95% technical malathion and an acid hydrolysate of corn protein) was repealedly applied to small portions of navel orange trees in an orchard in Coatepec, Veracruz, Mexico, the number of adult Anastrepha ludens (Loew) trapped in the treated area was 85-98% less than the number trapped in the check area, even though reinfestation from surrounding untreated groves was probably constant. Also, the number of larvae-per-kilo was reduced as much as 84% in tree fruit and slightly more in fallen fruit. The fruit produced in the treated areas was of local market quality except at the spring peak of the population of the flies and probably could have been exported after fumigation. The increase in the numbers of whiteflies, probably cloudy-winged whiteflies, Dialeurodes citrifolii (Morgan), in the treated area may be attributable to the increased mortality of green lacewings, chrysopa sp.