(3R(*),5S (*),6R (*))-3,5-dimethyl-6-(methylethyl)-3,4,5,6-tetrahydropyran-2-one, a third sex pheromone component forMacrocentrus grandii (goidanich) (Hymenoptera: Braconidae) and evidence for its utility at eclosion.

The compound (3R(),5S(),6R(*))-3,5-dimethyl-6-(methylethyl)-3, 4,5,6-tetrahydropyran-2-one was identified as a sex pheromone component ofM. grandii. Laboratory and field bioassays demonstrated that it elicits flight initiation, upwind anemotaxis, and casting in male wasps. The compound acts synergistically with (Z)-4-tridecenal, a previously identified sex pheromone component of femaleM. grandii, to increase male response to the aldehyde component. The source of the lactone was determined to be the mandibular glands of male and female wasps. At eclosion a majority of male-female and female-only cocoon masses released the lactone and attracted male wasps. Male-only cocoon masses were not attractive at eclosion and the lactone component was either not released or released at below-threshold concentration. Mating was observed to occur following eclosion in laboratory and field studies.