Aggregation pheromones ofDrosophila immigrans, D. phalerata, andD. subobscura

Aggregation pheromones ofDrosophila immigrans, D. phalerata andD. subobscura were demonstrated by testing attraction of adult flies to hexane extracts of the flies in a windtunnel bioassay. Extracts of adult males of all species attracted conspecific males and females. However,D. subobscura flies were attracted only when the extract (cVA) in the extracts of adult maleD. immigrans andD. phalerata. Both species were attracted to synthetic cVA. Male and femaleD. phalerata. Both species were attracted to synthetic cVA. Male and femaleD. subobscura produced 5,9-pentacosadiene, 5-pentacosene, 2-methylhexacosene and 5,9-heptacosadiene, while only maleD. subobscura produced (Z)-5-tricosene and minor amounts of cVA.