Journal of Chemical Ecology, Vol. 16, No. 10, 1990 SEDUCIN, MALE SEX PHEROMONE OF THE COCKROACH Nauphoeta cinerea: ISOLATION, IDENTIFICATION, AND BIOASSAY LEAM SRENG 1 Laboratoire de Zoologie Universit~ de Bourgogne 6, Bd Gabriel, 21100 Dijon, France (Received February 6, 1990; accepted May 25, 1990) Abstract--The male sex pheromone of the cockroach Nauphoeta cinerea was isolated from adult sternal glands and identified by gas chromatography-mass spectrometry. This pheromone, which attracts females from a distance, is a multicomponent blend. It is composed principally of three compounds: 3-hydroxy-2-butanone (acetoin), 2-methylthiazolidine, and 4-ethyl-2-meth- oxyphenol. A mixture of synthetic compounds in a ratio of 4:4:1 (2700 ng) elicits maximal response and short latency of response by receptive females, similar to that induced by male sternal gland extracts. Tested separately, each compound induces a positive response, but the moving times spent by females are generally longer than with the mixture or extracts. These three volatile compounds also are found in small amounts (about ~-of sternal glands) in tergal gland secretions licked by females. Acetoin also is found in the sternal and tergal glands of two closely related species Leucophaea maderae and Henschoutedeniaflexivitta. The biological relationship of each compound and pheromone blend to behavioral response is discussed. Key Worfls--Acetoin, 3-hydroxy-2-butanone, 2-methylthiazolidine, 4-ethyl- 2-methoxyphenol, 4-ethylguaiacol, male sex pheromone, pheromone blend, cockroach, Nauphoeta, Blattaria, Dictyoptera. INTRODUCTION Among cockroaches, chemical signals (pheromones) were shown to play an important role, especially in the regulation of sexual behavior (Roth and Willis, 1952, 1954; Roth and Barth, 1967; Barth, 1968), but so far only a few sex 'Present address: Laboratoire de Neurobiologie UPR27 CNRS (E8) 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 09, France. 2899 0098-0331/90/1000 2899506.00/0 9 1990 Plenum Publishing Corporation