Temporal distribution of PBAN-like immunoreactivity in the hemolymph of Mamestra brassicae females in relation to sex pheromone production and calling behavior

A direct enzyme-linked immunosorbent assay has been developed and applied t o the analysis of PBAN immunoreactivity in female hemolymph of the cabbage armyworm, Mamestra brassicae, PBAN-IR determinations have been carried out with third scotophase insects at different times of the photoperiod. The rh ythm of calling and the pattern of pheromone production by third scotophase females at different times of the photoperiod have also been determined. P BAN-IR and calling are well correlated. However, whereas pheromone titers d ecrease, both PBAN-IR levels and percentage of calling females remain high in the last hours of the scotophase, These results are discussed in the con text of the regulation of sex pheromone biosynthesis in M. brassicae. (C) 1 999 Wiley-Liss, Inc.