Recent Topics Posters
Sipes, Sedonia .
The host plant relationships of Diadasia chilensis, an eclectic specialist bee (Hymenoptera: Apoidea).
Diadasia chilensis (Spinola) is a solitary bee native to Chile. Previously published accounts of its host preferences were limited to a single mention of Sphaeralcea (Malvaceae) and Cynara (Asteraceae) as hosts. Most Diadasia species for which host preferences are known are pollen specialists on members of Malvaceae or Cactaceae. Of these, most of the South American Diadasia species have been tentatively characterized as Malvaceae specialists. I analyzed the scopal pollen loads of 38 D. chilensis females from ten localities in Chile. Asteraceous pollen types from at least three tribes (Cardueae, Astereae, and Lactuceae) were the most abundant taxa. Pollen loads averaged 85% asteraceous pollen by volume, but only 3% malvaceous pollen. However, D. chilensis is not a strict specialist, because only 63% of females carried pure loads (>90%) of asteraceous pollen. The rest carried either mixtures of asteraceous and other pollen types, or pure loads of other pollen types. Only three bees carried mixtures that included significant amounts of malvaceous pollen, and only two of these carried Sphaeralcea pollen. Although only one other Diadasia species (D. enavata) is known to specialize on an asteraceous host, some ofthe mallow- and cactus-feeding species use members of Asteraceae as minor hosts,possibly when their preferred host is in short supply. Unlike D. enavata, which limits its pollen collection quite strictly to Helianthus pollen, D. chilensis collects pollen from at least three asteraceous tribes (Cardueae, Astereae, and Lactuceae) plus non-asteraceous taxa. The known phylogenetic relationships within this bee genus suggest that the ancestor of Diadasia fed on malvaceous pollen, and that D. chilensis and D. enavata derived their preferences for Asteraceae from independent host switches.
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1 - Southern Illinois University, Department Of Plant Biology, 1125 Lincoln Drive, CARBONDALE, IL, 62901-6509, USA
Presentation Type: Recent Topics Poster
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM