Spider cuticular hydrocarbons

It has been suggested that the ethers, compounds unique to spiders, may provide reliable signals for pattern recognition and species determination. In contrast, a pattern of hydrocarbons, as used in several insect species, might be susceptible to contamination from cuticular hydrocarbons from insect prey remnants, which might alter the blends produced by the spiders and deposited on the webs (Schulz, 1997a, 1999). 

Allan R. A., Capon R. J., Brown W. V. and Elgar M. A. (2002) Mimicry of host cuticular hydrocarbons by salticid spider Cosmophasis bitaeniata that preys on larvae of tree ants Oecophylla smaragdina. J. Chem. Ecol. 28, 835-848. 

For example the total pentane extracts of the web and cuticle from two European Agelenidae and Amaurobiidae comprised a complex mixture of fatty acids, alcohols and long-chain aliphatic hydrocarbons (Prouvost et al., 1999 Trabalon et al., 1996, 1997 Trabalon and Assi-Bessekon, 2008 Tables 16.1 and 16.2). The qualitative composition of cuticular extract obtained was similar to that reported for most insects and scorpions. Hydrocarbons in spiders form complex and varied mixtures with unsaturated hydrocarbons. In those species, the hydrocarbon fraction consists of n-, monomethyl- and... 

Quantitative changes in lipid compounds on the silk and cuticle of females correlate significantly with changes in female sexual receptivity in spiders. For example, female T. atrica attach a contact sex pheromone to their web (Trabalon et al., 1997,2005 Prouvost et al., 1999). This pheromone consists of a complex mixture of saturated hydrocarbons, methyl esters (methyl tetradecanoate, methyl pentadecanoate, methyl hexadecanoate, and methyl octadecanoate) and their fatty acids (tetradecanoic, pentadecanoic, hexadecanoic, and cis,cis-9,12-octadecadienoic acids). The female uses cuticular compounds, which are applied to the silk in substantial amounts during web construction. Modification of chemical profiles makes the female attractive to males (Trabalon et al., 2005). Receptive females are different to unreceptive ones with respect to three fatty acids (hexadecanoic, octadeca-dienoic and octadecenoic acids) and three methyl esters (linoleate, oleate, and stearate) present on both the web and the cuticle. Our combined results from chemical analyses and behavioral assays demonstrate clearly that these contact compounds are quantitatively correlated with the behavior of spiders. 

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