Biological activity of synthetic hydrocarbon mixtures of cuticular components of the female housefly (Musca domestica L.).

Mixtures of (Z)-9-alkenes (C21-C33),n-alkanes (C21-C33), and mono- and dimethylalkanes (C27, C29), as components of the cuticular lipids washed from the female housefly (Musca domestica L.), were synthesized and assayed for their biological activity on male houseflies. The (Z)-9-alkenes and their hydrogenatedn-alkanes were synthesized from jojoba wax components by the appropriate chain elongation. The methylalkanes were prepared by Grignard coupling reaction of the appropriate alkyl halides, catalyzed by Li2CuCl4. Six- to 7-day-old virgin male houseflies exhibited the highest mating strike activity toward 6- to 7-day-old virgin females. The mating strike activity of the synthetic hydrocarbons was studied by exposing 6- to 7-day old virgin males to petrol-ether-rinsed 1 to 2-day-old dead females treated with these chemicals. (Z)-9-Tricosene was the most active hydrocarbon tested when it was applied in amounts of 10 μg to a washed dead female. Amounts of 5 μg of (Z)-9-tricosene did not cause sexual activity in the males. Mixture of (Z)-9-alkenes showed low activity when applied at 10-μg amounts. However, when mixtures were made of 5 μg of (Z)-9-tricosene with 5 fig of each of certain mixtures of (Z)-9-alkenes, the striking activity became as high as that of 10 μg of (Z)-9-tricosene. This might be a synergism effect. The mixtures ofn-alkanes, as well as the mono- and dimethylalkanes, showed moderate activity. When (Z)-9-tricosene was added to these materials no increase in male activity was observed.