Pheromone extract of the female orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (SM) (Diptera: Cecidomyiidae), was analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry (MS), employing fused silica columns coated with DB-5, DB-210, DB-23 or SP-1000. These analyses revealed a single, EAD-active candidate pheromone which was identified as 2,7-nonanediyl dibutyrate. In experiments in wheat fields in Saskatchewan, traps baited with (2S,7S)-2,7-nonanediyl dibutyrate attracted significant numbers of male SM. The presence of other stereoisomers did not adversely affect trap captures. Facile synthesis of stereoisomeric 2,7-nonanediyl dibutyrate will facilitate the development of pheromone-based monitoring or even control of SM populations.

No abstract

This study investigated pheromone communication and mating behaviour of the coffee white stem borer (CWSB), Xylotrechus quadripes (Coleoptera: Cerambycidae), in South Yunan, China. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of volatiles released by male and female CWSB identified 2-hydroxy-3-decanone and 2,3-decanedione as male-specific candidate pheromones. Further GC-EAD and GC-MS analyses confirmed that only (S)-2-hydroxy-3-decanone is produced by male CWSB and elicits antennal responses by male and female CWSB. In field experiments, 2-hydroxy-3-decanone as a trap bait afforded capture of one female CWSB, and in laboratory experiments it weakly attracted female but not male CWSB. Complex mating behaviour in CWSB includes: 1) attraction of potential mates by both sexes; 2) repeated landings (with ever decreasing distance) of a female next to a male; 3) males dashing to a nearby female; 4) rejection of mating attempts by females; 5) post-mating female guarding by males; and 6) size-dependent mating success of males. Considering this complex mating behaviour, lack of direct flight towards pheromone sources, mating near pheromone-baited traps, and only moderate attractiveness of (synthetic) pheromone, pheromone-based trapping of females does not seem to be a viable strategy for managing CWSB populations in China.

No abstract

No abstract