Citation: Chauhan, K.R., Zhang, Q.-H., Aldrich, J.R. 2004 Iridodials: Enantiospecific synthesis and stereochemical assignment of the pheromone for the Goldeneyed lacewing, Chrysopa oculata. Tetrahedron Letters. 45(17):3339-3340. Interpretive Summary: Green lacewings (Chrysopidae), are some of the most common predators of aphids and other soft-bodied insects and, because of their commercial availability and resistance to insecticides, chrysopids are among the most commonly released predators for augmentative biological control. While green lacewings are increasingly being released for biocontrol, methods are still needed to retain the predators near augmentation sites and/or to attract wild predators to target areas. In our efforts to search for pheromones of the goldeneyed lacewing Chrysopa oculata, one of the most common lacewings in the eastern United States, a single compound known as iridodial was discovered to be the key attractant (pheromone) produced by this insect for aggregation. The pheromone, the first identified and conveniently synthesized for this kind of insect, attracts other male lacewings, and may draw female lacewings to the vicinity. To establish absolute configuration, and to prepare sufficient quantities of pure iridodial, a convenient synthesis was accomplished from readily available starting materials. These findings should be of interest to scientists studying chemicals affecting predator behavior, and may be of practical utility in manipulating natural or artificially augmented populations of lacewings for enhanced biological control.
Technical Abstract: 1R,2S,5R,8R ; 1R,2S,5R,8S ; 1S,2S,5R,8R and 1S,2S,5R,8S-iridodials have been synthesized in 5 steps from 4aS,7S,7aR and 4aS,7S,7aR-nepetalactones, major components of catnip oil. 1R,2S,5R,8R-Iridodial is a male-produced male-aggregation pheromone for Chrysopa oculata, the first pheromone of any kind identified for lacewings.