3.5 Electrophysiological responses of male Ostrinia
nubilalis
We studied electrophysiological responses of male O. nubilalisinsect antennas to pure chemical pheromone components, BioPhe product,
and several blends. As expected, EAG responses of ECB Z-race male moths
were higher for 100 ng Z 11-14:OAc than for E 11-14:OAc
(Figure 5A). Also, the 97:3 (Z 11-14:OAc/E 11-14:OAc)
mixture at 100 ng dose elicited the same magnitude of response as the
major pheromone component (Z 11-14:OAc). The biologically-derived
pheromone BioPhe at 100 ng elicited a significantly lower response, as
expected, because Z 11-14:OAc is present just at 7.2% ergoand only about 7 ng of Z 11-14:OAc were directed to the antenna.
When the quantity of BioPhe was increased ten-fold, the EAG response was
also increased. In this treatment, the amount of Z 11-14:OAc
present in the biologically-derived mixture was of the same order of
magnitude as the reference (i.e ., ~70 ng).
However, it should be noted, that some of the other BioPhe components
may also contribute to the augmented response recorded. In this context,
we tested the effect of 14:OAc, given the fact that it comprises about
50% of BioPhe. At 50 ng dose, analogous to that contained in 100 ng
BioPhe, it was clearly detected by the antenna but to a much lesser
degree than the reference compound.