The mass spectrometric data of the EAD active compounds suggest the compounds are a mixture of saturated and unsaturated aldehyde, acetate and hydrocarbon compounds. Comparison of the retention times of the EAD active compounds with synthetic compounds on a non-polar column enabled the tentative identification of six EAD active compounds as follows: (Z)-11-hexadecenal (Z11-16:Ald), hexadecanal (16:Ald), (Z)-11-hexadecenyl acetate (Z11-16:Ac), hexadecyl acetate (16:Ac), octadecanol (18:OH) and (3Z,6Z,9Z)-tricosatriene (Z3Z6Z9-23:Hy). GC/MS analysis of DMDS-derivatized extract showed an adduct with a molecular ion at m/z 332 (13%), the diagnostic ions at m/z 117 (63%, C6H13S + ) and m/z 215 (100% C12H23OS + ), indicating the addition of DMDS to a double bond at position 11 for Z11-16:Ald. In addition, the DMDS-derivatized extract showed another adduct with a molecular ion at m/z 376 (11%), and the diagnostic ions at m/z 117 (57%, C6H13S + ) and m/z 259 (100% C14H27OS + ), indicating the addition of DMDS to a double bond at position 11 for Z11-16:Ac. The geometry of the double bond in the two unsaturated compounds was confirmed by the chemical analysis of both E and Z isomers of both compounds. The mass spectrum data of compound 6 were very similar to the mass spectrum data provided in and . Further confirmation of the identity of the compounds present in the gland extracts was confirmed by comparing authentic standards with the gland extract on a polar capillary column. The chemical composition of the sex pheromone gland from females collected from Lincoln was similar to females collected from Little River.