Clerodendrins: Feeding stimulants for the adult turnip sawfly, Athalia rosae ruficornis, from Clerodendron trichotomum (verbenaceae).

Larvae of the turnip saw fly, Athalia rosae ruficornis, feed exclusively on plants of the family Cruciferae.However, the adult insects are attracted to a Verbenaceae plant, Clerodendron trichotomum, and feed voraciously on its leaf surfaces.Twokairomonal substances that stimulate this feeding behavior were isolated from the leaves of C. trichotomum and identified.They are called clerodendrin B and D. Another substance called clerodendrin A is a major component in the leaves of C. trichotomum, but it did not elicit a feeding response in the saw fly in spite of its structural similarity to clerodendrin B and D. The ecological functions of these kairomonal substances for the turnip saw fly are suggested here.Three closely related turnip saw fly species namely, Athalia rosae ruficornis (Jakovlev), A. lugens infumata (Marlat)and A. japonica