The role of host-plant odours in the attraction of Leptomastix dactylopii and Leptomastidea abnormis, parasitoids of the citrus mealybug, Planococcus citri.
Leptomastix dactylopii and Leptomastidea abnormis are used as biological control agents against Planococcus citri on ornamental plants in the greenhouse in the Netherlands. Olfactometer experiments showed that both parasitoids are attracted to P. citri. Leptomastix is attracted by a synomone produced by Stephanotis infested with the mealybug. Passiflora did not produce such a synomone, and Leptomastidea did not respond to the synomone produced by Stephanotis.