Some properties of the female sex pheromone of the Colorado potato beetle Leptinotarsa decemlineata Say (Col Chrysomelidae)

The female sex pheromone of L. decemlineata is an aphrodisiacum, switching on mating behaviour in contacting males. A biotest is described to estimate quantitatively the exciting power of a subject (female, isolated elytrae, glass dummy coated with extract) to males. The pheromone is present only in fertile females, also in freshly killed ones. It can be extracted by organic solvents. A dummy imitating a beetle's abdomen and contaminated with the residue of a female s wash solution is exciting to males too. Suitable solvents are ethylalcohol, acetonet, hexane. By this, the pheromone of 0,1 female is detectable. The residue can be taken up again with the same or an other solvent. The solution can be stored at -18 degrees C without significant losses, but at temperatures >+5 degrees C their efficacy diminishes during 2 weeks. The exciting efficacy of the dry residue desreases to about 50% during nearly 4 weeks (at +22 degrees C) or 9 weeks (at +5 degrees C). The pheromone resists heating to about +160 degrees C and is destroyed at higher temperatures.