A braconid parasitoid, Diachasmimorpha tryoni (Cameron), was released from the air into Guatemalan coffee plantations that contained Mediterranean fruit flies, Ceratitis capitata (Weidemann). Parasitoid adults were chilled, placed in paper bags, and dropped from an altitude of 100 m and at an airspeed of ~ 130 km/h. Releases were made at four different densities over a period of two years. At the higher release rates parasitism levels reached as high as 84%. The feasibility of using a more technically sophisticated aerial release technique, the auger sterile-insect release machine utilized in C. capitata sterile-fly aerial eradication projects in California and Florida, was also examined. Chilled D. tryoni either alone or in combination with chilled, sterile C. capitata , were dropped over target areas and the released parasitoids examined for mortality and damage. Samples of released parasitoids were taken and tested for 'flight ability'; i.e. flight response after an opportunity to recover from chilling. There was no evidence of significant mortality due to aerial release, and the flight-ability of insects released at various rates and altitudes did not significantly differ from chilled controls that were not released from an airplane.

Field trials were conducted in Guatemala to determine the effect of addition of methyl-substituted ammonia derivatives (methylamine, dimethylamine or trimethylamine) to a food-based synthetic attractant for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). and the Mexican fruit fly, Anastrepha ludens (Loew). Addition of trimethylamine to traps baited with ammonium acetate anti putrescine increased capture of C. capitata, but not A. ludens, over traps baited with ammonium acetate and putrescine alone, in all tests. Addition of methylamine or dimethylamine had no effect on either species, More C. capitata were captured in adhesive paper cylindrical traps baited with tested combinations of synthetic lures than in McPhail traps baited with liquid protein bait (torula yeast solution). In tests conducted during the dry season in Guatemala, more female A. ludens were captured in liquid protein-baited McPhail traps than in adhesive paper cylindrical traps baited with ammonium acetate. putrescine, and trimethylamine. However during the rainy season, adhesive paper cylindrical traps baited with ammonium acetate. putrescine, and trimethylamine captured significantly more female A. ludens than liquid protein-baited McPhail traps. No C. capitata were captured in traps baited with trimethylamine alone, indicating that trimethylamine is a potent synergist to ammonium acetate and putrescine for the capture of C. capitata.

A membrane-based formulation method that provided a constant release rate of synthetic pheromone for the papaya fruit fly, Toxotrypana curvicauda Gerstaecker, was developed. Release rate measurements over 23 days indicated that lures loaded with 5, 15, 25, and 50 mu l of synthetic pheromone released an average of 120, 360, 580 and 1120 ng per hr and the half-life of the lures was estimated to be 67, 184, 300 and 48 days, respectively. Field tests conducted in Mexico compared efficacy of blank and pheromone-baited sticky green spheres, cylindrical traps made from green opaque plastic that either contained a toxicant or were coated with sticky material, and cylindrical traps prepared from green sticky paper. Green opaque traps containing a toxicant and sticky paper traps captured approximately five times more papaya fruit flies than either the sticky-coated green opaque traps or the sticky-coated green spheres, and the presence of pheromone did not affect numbers of flies captured. Thus, the combination of the green color and the cylindrical shape provided a visual cue sufficient for papaya fruit fly capture. The pheromone lure significantly increased trap capture in similar tests conducted in Guatemala. Capture was highest in the sticky paper traps and in sticky-coated spheres. Use of the membrane-based synthetic pheromone in a cylindrical trap may provide an effective tool for monitoring papaya fruit flies.

Tests of the capture of wild Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were made using a commercially produced adhesive paper available in several different colors as an insert in trimedlure-baited Jackson traps. Colors tested included fluorescent orange, fluorescent yellow fluorescent light green, dark green, black, and White. These inserts were compared with the standard white inserts, which use sticky material that is manually applied. Tests were conducted in both citrus groves and coffee fields in Guatemala, and in a coffee field in Hawaii. Generally, inserts made with the fluorescent colors captured more flies than those with nonfluorescent colors. Traps with light green inserts captured a higher percentage of total flies than did traps with the standard white inserts in 3 of the 4 trials. Traps containing either yellow or orange inserts captured significantly more flies than the standard white insert in 2 of the 4 trials. Traps containing black inserts tended to catch a relatively low percentage of flies. There were differences in host species, host fruit availability, and fruit fly population levels among the various trials. These factors may influence the role of color cues in the capture of male flies by trimedlure-baited traps.