Monoalkenes as contact sex pheromone components of the woodwasp Sirex noctilio.

A pheromone on the cuticle of females of the woodwasp Sirex noctilio, a recently introduced pest of pines in North America, induces conspecific males to attempt copulation. Dead females washed with hexane did not elicit copulation attempts from males, whereas reapplication of a female hexane body wash onto the cuticle of dead females elicited copulation attempts by 65% of males tested. Analysis of the hexane extract revealed saturated and unsaturated hydrocarbons as major components of the female cuticle. Behavior-guided fractionation of the female body wash led to the identification of three components, (Z)-7-heptacosene, (Z)-7-nonacosene, and (Z)-9-nonacosene, of the sex pheromone of S. noctilio that elicited copulatory responses from males.

Venom alkaloid chemistry of Australian species of the Monomorium rothsteini complex, with particular reference to taxonomic implications.

A comparison of the morphology and of the venom alkaloids of the Australian Monomorium rothsteini complex was undertaken. These ants were collected in Australia from western New South Wales, northern Queensland, and northern Northern Territory. Additionally, samples from the M. sordidum complex and M. carinatum complex were examined. Thirteen previously described trans-2,5-dialkylpyrrolidines were detected in these ants, along with the novel trans-2-ethyl-5-[(Z)-tridec-4-enyl]pyrrolidine (6), whose structure was confirmed by synthesis. The extent of variation and the correlation observed in the morphology and venom chemistry in M. rothsteini samples is very strongly indicative of multiple species in this complex. The presence and location of the C==C bond in 6 reinforces the remarkable structural similarity of the 2-ethylpyrrolidines in these Monomorium species to the 2-methylpiperidines in the venoms of many Solenopsis species, and may represent convergent evolution of biosynthetic processes in different genera of solenopsidine ants.