Skip to main content
ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #207682
Title: Solitary invasive orchid bee outperforms co-occurring native bees to promote fruit set in an invasive Solanum.

Author
item LIU, HONG - UNIVERSITY OF FLORIDA
item Pemberton, Robert

Submitted to: Oecologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2008
Publication Date: 12/9/2008
Citation: Liu, H., Pemberton, R.W. 2009. Invasive orchid bee outperforms co-occurring native bees to promote fruit set in an invasive Solanum.. Oecologia 159: 515-525.

Interpretive Summary: An orchid bee, Euglossa viridissima, has recently naturalized in Florida. Because orchid bees are known to be important pollinators in their native habitats in tropical America, this be could become an important pollinators of selected plants in Florida. Preliminary observations indicated that the bee visited the flowers of turkey berry (Solanum torvum) a Federal Noxious Weed which invades natural areas. Flowers of S. torvum have the specialized buzz pollination syndrome in which the pollen can be removed from terminal pores in the pollen sacks only when vibrated out by particular bees. Orchid bees and some native bees are buzz pollinators but honey bees are not. Through timed floral visitor watches and six pollination treatments: open, open with pollen supplement, single visits from native sweat bees (Halictidae), single visits from the orchid bee, and small and large mesh cages (to deny or allow the orchid bee access, respectively) at two sites, we found that the orchid bee outperformed the native bees. The orchid bee was superior in all measures of pollination processes of S. torvum. Moreover, when the orchid bee was excluded, the flowers set 1/4 as many fruits as when the bee was given the access. Where the orchid bee was abundant, its frequent and efficient visits completely eliminated pollen limitation in S. torvum plants. The overall importance of the orchid bee as a pollinator was 41 times higher than the sweat bees. This specialized invasive mutualism may promote populations of both the orchid bee and this noxious weed. The orchid bee may also promote other weeds employing this buzz pollination system, including other Solanum species and also Senna (Cassia) species.

Technical Abstract: Little is known about the potential effects of naturalized solitary or semi-social bees on the environment. We took advantage of the recent naturalization of an orchid bee, Euglossa viridissima, in southern Florida to study the effects of this semi-social bee on reproduction of Solanum torvum, an invasive shrub. Flowers of S. torvum have a specialized buzz pollination syndrome. Through timed floral visitor watches and six pollination treatments: open, open with pollen supplement, single visits from halictid bees, single visits from E. viridissima, and small and large mesh cages (to deny or allow E. viridissima access, respectively) at two sites, we found that the orchid bee outperformed the native bees. The orchid bee was superior in all measures of pollination processes of S. torvum. Moreover, when the orchid bee was excluded, the flowers set 1/4 as many fruits as when the bee was given the access. Where the orchid bee was abundant, its frequent and efficient visits completely eliminated pollen limitation in S. torvum plants. The overall importance of the orchid bee as a pollinator was 41 times higher than that of halictid bees. This specialized invasive mutualism may promote populations of both the orchid bee and this noxious weed.