SEXUAL SELECTION AND PHEROMONES: THEORY AND DATA.

Klaus Jaffe and Aivle Cabrera
Depto. Biologia de Organismos, Universidad Simon Bolivar, Apartado89000, Caracas 1080A, Venezuela

Complex simulation of biological evolution suggests that mate selectionis a basic component of natural selection and must be present in most sexualorganisms, influencing biological evolution. Mate selection criteriamust be very strict and tailored to detect "good genes" in order to beevolutionary stable. Sex pheromones are normally viewed as a meansfor species-, kin-recognition and sexual recognition. The theoretical studysuggests that sex pheromones could have a function in mate selection. Wereviewed the literature of the last 7 years, selecting information aboutthe biology and chemistry of insect sex and aggregation pheromones finding: In 100 % of the reports of aggregation pheromones found among Coleoptera,insects responded best to blends or mixes of various chemicals ; Sex pheromonesof Lepidoptera elicit maximal response if only one chemical is presentin 50 % of cases, and insects respond preferentially to mixes inonly 25 % of cases. In another 25 % of cases a few EAG active compoundselicit maximal attraction whereas other EAG active compounds inhibit thisattraction. These results suggest that the chemical composition of sexpheromones, but not of aggregation pheromones, are the product of sexualselection. Males select for females which are able to perform difficultbiosynthetic tasks, i.e., synthesize highly pure chemicals or specificblends of them. Unfortunately, only few of the data available gives accurateinformation on EAG, chemistry and behavior of pheromones. This way of lookingat sex pheromones may help in a better interpretation of experimental resultsand may be useful for improving the use of sex pheromones in insect pestmanagement.