Effects of pH on feeding responses in the apple maggot XXXX , Rhagoletis pomonella (Diptera: Tephritidae).

@entity969 @entity238
Phagostimulatory effects of pH values of @entity969 on Rhagoletis pomonella adults were studied in the laboratory. Flies were standardized for age, diet and food deprivation. Two presentation schemes were employed. The first varied pH value (3.0-10.0) with @entity969 concentration kept constant at 40%. The second varied both @entity969 concentration (8%, 24% and 40%) and pH value (5.0-8.0). @entity238 feeding propensity was evaluated by observation of @entity238 acceptance or rejection of @entity969 and duration of feeding. When tested on red wooden spheres treated with 40% @entity969 , @entity238 feeding acceptance was significantly greater when pH ranged from 5.0 to 8.0, and duration of feeding was significantly longer at pH 6.0-7.0. At pH </=4.0 or pH >/=8.0, feeding propensity was significantly reduced. Decrease in @entity969 concentration significantly increased @entity238 sensitivity to pH. Males were more responsive to varying pH than females. The @entity969 pH shown to stimulate maximal feeding response was 6.4. Such information is relevant to formulation improvement of a coating mixture of @entity969 and insecticide applied to red spheres as part of apple maggot @entity238 control programs.
