English, Carol T , Sommers Saunders, James , Adams, Rogan , Bruederle, Leo .
Annual Variation for Effective Pollination in Pentemon degeneri Crosswhite (Plataginaceae), a Rare Colorado Endemic.
Field research addressing pollination biology in Penstemon degeneri Crosswhite (Plantaginaceae), a rare Colorado endemic, was conducted at three sites over two field seasons characterized by extreme variation for precipitation. Although overall species diversity was similar each year, the visitor guild differed dramatically over this period, as did effective pollination. Two bumblebee species (Apidae) were determined to be highly effective pollinators in 2007, yet few bumblebees were observed in 2008 and these carried little body pollen and no scopal pollen. Mason bees (Megachilidae) were also determined to be effective pollinators in 2007, yet they occurred in relatively low numbers in 2007 and only at the high elevation site. Mason bees were most abundant at all three sites in 2008 and were 80% faithful to P. degeneri pollen, carrying copious amounts of body pollen. Pseudomasaris vespoides, a pollen wasp that has been described as being oligolectic for Penstemon, was encountered infrequently in 2007, yet it was one of the most frequent visitors in 2008. Furthermore, nine of the ten individuals captured in 2008 carried copious amounts of body pollen. These results suggest that seasonal precipitation can influence strongly the visitor guild, as well as effective pollination in P. degeneri.
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1 - University of Colorado Denver, Biology, 1200 Larimer St Suite 5014, Denver, CO, 80217, USA
2 - University of Colorado at Denver and Health Sciences Center, Biology, Campus Box 171, P.O. Box 173364, Denver, Colorado, 80217, USA
Presentation Type: Poster:Posters for Topics
Location: Event Tent/Cliff Lodge
Date: Monday, July 27th, 2009
Time: 5:30 PM