Two encyrtid species, Acerophagus coccois and Aenasius vexans, parasitoids of the cassava mealybug Phenacoccus herreni use a contact kairomone from the body surface of their host as a host-location stimulant. The kairomone was synthesized and identified as O-caffeoylserine based on a combination of chromatographic methods. The synthetic compound was determined to be active.
Shinoda; Sato, Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan, 1929, vol. 49, p. 71; dtsch. Ref. S. 7