Sex pheromones are critical for reproductive success in most species o
f Lepidoptera and their production is regulated by the action of phero
mone biosynthesis activating neuropeptides (PBAN). These peptides, com
posed of 33-34 amino acids, have approximately 80% sequence homology a
nd share the C-terminal sequence FSPRL-NH2, which has been shown to be
the minimum sequence required for pheromonotropic activity. This pent
amer is structurally similar to the active core (FXPRL-NH2, X = V, T,
or G) of the insect myotropic pyrokinins. Structure-activity studies h
ave shown that all of the pyrokinins have various degrees of pheromono
tropic activity and that some have a superagonistic effect. Peptides t
hat only have sequence homology with PBAN in the C-terminal pentapepti
de region, but that are pheromonotropic, also have been identified fro
m moths. These findings suggest that induction of pheromone biosynthes
is may be regulated by more than one peptide, that PBAN may have a num
ber of physiological functions, and that these peptides regulate induc
tion of pheromone production in a variety of ways.