Submitted to: Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2006
Publication Date: 8/7/2006
Citation: Pemberton, R.W., Wheeler, G.S. 2006. Orchid bees don’t need orchid mutualists, evidence from the naturalization of an orchid bee in florida. Ecology. 87:1995-2001.
Interpretive Summary: The orchid bee-perfume orchid mutualism has been considered to be a prime example of co-dependent mutualism. The male bees collect fragrance compounds from the flowers of orchids (which offer no food reward), pollinating the orchids in the process. The males store these chemicals in their hind legs and use them in their courtship. The naturalization of an orchid bee, Euglossa viridissima, from Central America, in southern Florida, where no perfume orchids occur, provided a unique opportunity to better understand this mutualism. The bee was observed to dissolve volatile oils from the leaves of basil and allspice. Analysis of chemicals collected in the bees tibiae identified 55 compounds including 27 known from 9 of the bee’s orchid mutualists in Central America. The bee managed to collect needed compounds, from the leaves of basil and other plants. This indicates that the mutualism is facultative for the bees even though it is known to be obligatory for the orchids. In addition, the bee, which is has become abundant in southern Florida, collects pollen and nectar from the flowers of diverse native, agricultural, horticultural and invasive plants. Orchid bees are important pollinators in their native region. Given the abundance of E. viridissima in southern Florida, and the many plants it visits, the bee may come to influence the abundance of selected species through its pollination activities.
Technical Abstract: Almost 200 species of orchid bees are the exclusive pollinators of nearly 700 specialized orchids in the Neotropics. This well-known mutualism involves orchids, called perfume orchids, which produce species specific blends of floral fragrances, and male orchid bees, which collect and use these fragrance compounds during their courtship. We report here the naturalization of an orchid bee, Euglossa viridissima, in southern Florida, where perfume orchids are absent. Chemical analysis of the contents of the fragrance storage organs in the hind tibias of 59 male bees collected in Florida identified 55 fragrance compounds, including 27 known from the perfumes of 9 species of E. viridissima’s orchid mutualists in MesoAmerica. Aromatic leaves, such as basil, were found to be important surrogate sources of needed fragrance compounds in Florida. The bee’s ability to live and become abundant in the absence of its orchid mutualists suggests that the orchid bee-perfume orchid mutualism may be facultative for the bees, even though it is obligatory for the orchids. This invasive bee visits and potentially pollinates the flowers of many plants in Florida, behavior that could promote the abundance of selected exotic and native species.