The sex attractant pheromone blend of Hemileuca maia (Lepidoptera: Saturmid
ae) from the vicinity of Baton Rouge, Louisiana, has been identified. The m
ajor component of the blend is (E10,Z12)-hexadeca-10, 12-dienal (E10,Z12-16
:Ald), in combination with the minor components (E10,Z12)-hexadeca- 10,12-d
ien-1-ol (E10,Z12-16:OH), and (E10,Z12)-hexadeca- 10, 12-dien-1-yl acetate
(E10,Z12-16:Ac). Ratios of the compounds in extracts of female pheromone gl
ands varied around a mean of 100:7.4:6,3. None of the three components were
attractive to male moths when tested as single components. Several other c
ompounds were tentatively identified from female pheromone gland extracts,
including E10,E12-16:Ald, E10,E12-16:OH. and E10,E12-16:Ac, but addition of
these components, either alone or in combination, at biologically relevant
rates, did not significantly increase the attractiveness of lures. The sat
urated analogs, hexadecanal, hexadecanol, and hexadecyl acetate, also were
identified in gland extracts, but had no apparent effect as pheromone compo
nents.