Abstract
Using proboscis extension (unconditioned response) to sucrose (unconditioned stimulus), individual blowflies (Phormia regina) were classically conditioned to saline and to water (conditioned stimuli) with sensitization controls, thus providing unique, independently replicated evidence both of learning in Diptera and of reliably measured individual differences. Directional and stabilizing selection have bred high and low performance lines markedly different from an unselected control line as a step in the analysis of behavior-genetic correlates. This replicates and extends previous selection analysis with improved conditioning technique. Also, some unwarranted claims of learning in Diptera are discussed.