Adult predators and parasitoids generally require floral resource plants as part of their diet. The availability of such suitable plant foods to predators and parasitoids can promote sexual maturation, prolong longevity, improve reproductive capacity or parasitic rate and motivation to seek hosts, and increase the female sex ratio of offspring, all of which can significantly improve the ability of predators and parasitoids to act as biological control agents. The ability of adult predators and parasitoids to exploit floral foods are significantly affected by the floral architecture, the olfactory and visual signals emitted by the plant, and the gustatory response of predators and parasitoids to honey or pollen. Floral resource plants also can act as supplementary foods for pest species, thereby increasing their capacity to cause crop damage. In depth study of the effects of different floral resource plants on both pests and their natural enemies is required in order to determine how floral resources might be able to be used regulate the ratio of natural enemies to pests.