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, switc hing on mating behaviour in contacting males. A biotest is described t o estimate quantitatively the exciting power of a subject (female, iso lated elytrae, glass dummy coated with extract) to males. The pheromon e is present only in fertile females, also in freshly killed ones. It can be extracted by organic solvents. A dummy imitating a beetle's abd omen and contaminated with the residue of a female s wash solution is exciting to males too. Suitable solvents are ethylalcohol, acetonet, h exane. 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 tem peratures >+5 degrees C their efficacy diminishes during 2 weeks. The exciting efficacy of the dry residue desreases to about 50% during nea rly 4 weeks (at +22 degrees C) or 9 weeks (at +5 degrees C). The phero mone resists heating to about +160 degrees C and is destroyed at highe r temperatures.