PH EFFECT ON THE ATTRACTIVENESS OF A CORN HYDROLYSATE TO THE MEDITERRANEAN FRUIT-FLY AND SEVERAL ANASTREPHA-SPECIES (DIPTERA, TEPHRITIDAE)

Field trials were conducted to determine the attractiveness of aqueous formulations of a protein bait, NuLure, as compared with a standard b ait of pelletized torula yeast plus sodium borate for the Mediterranea n fruit fly, Ceratitis capitata (Weidemann); the Mexican fruit fly, An astrepha ludens (Loew); and other Anastrepha spp. addition of 1-10% bo rax to 10% NuLure solution increased bait pH, which corresponded direc tly with increase in number of female C. capitata trapped in field tri als. The percentage of female C. capitata trapped with NuLure at a pH of 8.6 was significantly greater than with traps baited with five toru la yeast plus borax pellets. NuLure + 1% borax attracted significantly fewer male C. capitata than either torula yeast plus borax pellets -o r NuLure + 5 or 10% borax. Significantly fewer female and male A. lude ns were attracted by the NuLure + 1% borax than most of the other bait s tested. Capture of female and male flies of other Anastrepha spp. ge nerally paralleled the preference in attraction of A. ludens to the va rious protein baits.