SUMMARY An unstable compound with an intense odor of “burnt pineapple” was isolated as a major component of a pineapple flavor concentrate. This compound was tentatively identified as 2,5‐dimethyl‐P‐hydroxy‐3(2H)‐furanone (I).

In the field, both sexes of the western pine beetle, Dendroctonus brevicomis, are attracted by the female-produced bicyclic ketal exo-brevicomin; this response is enhanced by myrcene (a constituent of the beetle's host, ponderosapine), which is not an attractant by itself. This synergism may be part of the phenomenon of the mass attack on its host. Temnochila virescens chlorodia, one of the principal insectan predators of this beetle, is attracted by exo-brevicomin alone.

No abstract