Evidence of sexual attraction by pheromone in the cedar web-spinning sawfly

• Published in: Canadian entomologist 2007-10, Vol.139 (5), p.713-721
• Main Authors: Nemer, Nabil, Kawar, Nasri S., Kfoury, Linda, Frerot, Brigitte
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal reproduction; Animal, plant and microbial ecology; Animals; Autoecology; baits; Biological and medical sciences; biosynthesis; Cedrus libani; Cephalcia; Cephalcia tannourinensis; Control; diurnal variation; dose response; Entomology; Fundamental and applied biological sciences. Psychology; Hormones; Hymenoptera; Insect Management / Contrôle des insectes; Insects; Integrated pest control; mating behavior; olfactometry; Pamphiliidae; pheromone traps; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrata; Protozoa. Invertebrates; sawflies; sex attractants; sex pheromones; Studies; trapping
• ISSN: 0008-347X; 1918-3240
• DOI: 10.4039/n06-042

The cedar web-spinning sawfly, Cephalcia tannourinensis Chevin (Hymenoptera: Pamphiliidae), is a pest that has been causing serious damage to cedar (Cedrus libani) forests in Lebanon since 1990. The existence of a sex pheromone was shown in field experiments in a cedar forest in Lebanon and in laboratory tests in olfactometers with and without airflow. More males were caught in traps baited either with virgin females or with a hexane extract of the whole female body than in traps baited either with males alone or with mixed males and females. Male and female C. tannourinensis were active during the day. Mating and pheromone production were observed to occur during midday hours (1000–1400) in the field and under laboratory conditions. Olfactometer tests with extracts prepared from different body parts of the female indicated that the pheromone is produced in the abdominal region, and tests with different dilutions of female extract showed that the male response is dose-dependent. La thendrède du cèdre, Cephalcia tannourinensis Chevin (Hymenoptera : Pamphiliidae), cause de graves dommages dans les cédraies libanaises (Cedrus libani) depuis 1990. Des études menées sur le terrain par piégeage sexuel et au laboratoire par olfactométrie ont permis de mettre en évidence l'existence d'une phéromone sexuelle produite par les femelles et attractive pour les mâles. Les mêmes tests ont démontré que l'activité sexuelle est diurne et limitée à un moment de la journée qui se situe entre 1000 h et 1400 h; que la phéromone est extractible dans l'hexane et que l'abdomen serait le siège de la production. La réponse des mâles est dépendante de la dose.