Nectar Constituents of the Cactaceae

Abstract

The nectar constitution of 45 cactus species representing taxa serviced by numerous pollinator classes is reported with respect to sugar concentration, sugar composition, and caloric content per flower. Sugar concentration do not differ significantly among hawkmoth-, hummingbird, and bat-visited cactus flowers. A tendency to sucrose richness is present in nectars taken by moths and birds, whereas balanced and hexose-rich nectars occur in bat-visited cacti. Energy content per flower shows a difference between bat and other visitor types.