The prey of 132 species of Bembicini (Hymenoptera) that have been studied is reviewed. About three quarters of the species prey on Diptera, and it is believed that fly predation is ancestral in the group. Eleven species make occasional or regular use of other insects as prey in addition to Diptera (Lepidoptera, Hymenoptera, Neuroptera, Odonata, and/or Homoptera), while 21 species of five genera prey on insects of these same five groups with no use of Diptera. It is hypothesized that this represents an evolutionary progression, whereby populations have experienced shortages of dipterous prey in the past and have broadened their sensory focusing to include other groups of flying insects. Behavior initially learned has, over time, been reinforced genetically to produce the currently observed radiation in prey choice within the group.
Insecta; Bembicini; prey choice; behavioral evolution
