Chemical analysis of oxygenated homosesquiterpenes: a putative sex pheromone from Lutzomyia lichyi (Diptera: Psychodidae)

Abstract

Lutzomyia lichyi (Floch & Abbonenc) is a suggested secondary vector ofLeishmania in Colombia. Taxonomically, L. lichyi is very closely related to the L. longipalpis (Lutz & Neiva) species complex. Male members of the complex can be distinguished by their sex pheromones which are produced in papules found grouped together in pale patches on tergites 3 or tergites 3 and 4. Male L. lichyi also have papules, very similar in appearance to those of the L. longipalpis species complex but distributed on tergites 4, 5, 6 and 7. Chemical analysis of male L. lichyi hexane extracts has revealed the presence of two novel oxygenated methylsesquiterpenes. The two major oxygenated terpenes found in the extract of L. lichyi males are tentatively characterized as a primary and tertiary alcohol. The mass spectrum of the proposed primary alcohol is very similar to the published mass spectrum of 3-methyl-␣-himachalene, the sex pheromone produced by the Jacobina chemotype of the L. longipalpis complex. The mass spectrum of the proposed tertiary alcohol also has similarities to the 3-methyl-␣-himachalene sex pheromone.

Olfaction in vector-host interactions

“…However, the Lu. longipalpis compounds are unusual in that the compounds found in two of the members of the species complex have an additional methyl group probably added in the early biosynthesis of the molecule (Hamilton et al 1999c) i.e. they have 16 carbons (C16, mw 218).…”

Correlation of male genital filaments and female spermathecal ducts in New World sand flies of the Lutzomyia intermedia species complex (Diptera: Psychodidae, Phlebotominae)

“…There would be a considerable risk of interspecific couplings in a situation of this type if the insects did not have some method of recognising members of the same species. Although sex pheromones have been described for a few species (Hamilton et al 1999) such isolating mechanisms are unknown for most sand flies. Nevertheless it is unlikely that the morphological diversity of the genitalia in Lutzomyia spp.…”

Sandfly pheromones: Their biology and potential for use in control programs

“…The sex pheromone of one member of the complex has been shown to be the novel C16 (3 × C5) monocyclic terpene (S)-9-methylgermacrene-B (Hamilton et al, 1996a(Hamilton et al, , 1999a and another the novel C16 bicyclic terpene, 3 methyl-α-himachalene (Hamilton et al, 1996b(Hamilton et al, , 1999b. These two L. longipalpis methyl sesequiterpenes are unusual in that they have an additional -CH 3 (methyl) group, probably added in the early biosynthesis of the molecule (Hamilton et al, 1999c). A further two members of the L. longipalpis species complex have different cembrene isomers i.e.…”