Biogeography of the yeasts of ephemeral flowers and their insects

Abstract

We studied specific yeast communities vectored by beetles, drosophilids, and bees that visit ephemeral flowers, mostly in the genus Hibiscus and in the families Convolvulaceae and Cactaceae, in the Neotropical, Nearctic, and Australian biogeographic regions. The communities consist mostly of yeasts in four clades centered around the genera Metschnikowia, Kodamaea, Wickerhamiella, and Starmerella. The largest geographic discontinuity occurs as a function of the nitidulid beetle species that dominate the non-pollinator insect visitors of the flowers. This partitions the New World, where the dominant beetle is in the genus Conotelus, from the Australian biogeographic region, dominated by species of Aethina. Distinct but sympatric insects may also carry radically different yeast communities.

Metschnikowia drakensbergensis sp. nov. and Metschnikowia caudata sp. nov., endemic yeasts associated with Protea flowers in South Africa

“…The genus Metschnikowia (and anamorphs in the genus Candida) is one of the dominant taxa found in these substrates (Lachance et al, 2001;Lachance, 2011). For example, the cosmopolitan Metschnikowia reukaufii, M. gruessii and M. koreensis have been isolated repeatedly from a wide diversity of flowers and associated bee, butterfly and bird pollinators in both the Old World and the New World (Hong et al, 2001;Pozo et al, 2011;Belisle et al, 2012).…”

“…Large-spored Metschnikowia species associated with beetles have distinct biogeographies, and their association with particular beetles and plants with restricted distributions may have favoured speciation by allopatry or peripatry (Lachance et al, 2001(Lachance et al, , 2003a(Lachance et al, , b, 2005(Lachance et al, , 2006aLachance & Fedor, 2014). The most striking example is the Metschnikowia hawaiiensis subclade, composed of six described and undescribed species associated with endemic nitidulid beetles of the genus Prosopeus and endemic plants of Hawaii (Lachance et al, 2005;Guzmán et al, 2013).…”

Starmerella meliponinorum sp. nov., a novel ascomycetous yeast species associated with stingless bees

“…collected on various flowers in Costa Rica were found to harbour several novel yeast species in the Starmerella clade, only two of which have been described (Lachance et al, 2001a). Another yeast, represented by a single strain, has been reported as 'Candida etchellsii sister 7?0 %' (Lachance et al, 2001b). During a study of yeasts associated with stingless bees in Brazil, an ascospore-forming species was frequently isolated from food resources and adults of these insects.…”

Metschnikowia orientalis sp. nov., an Australasian yeast from nitidulid beetles

“…These were the only representatives of that species in very large collections not only in Rarotonga, but also in New Caledonia, two localities in the Fiji islands and a wide array of sites in eastern and northern Australia (Lachance et al, 2001). In June 2005, we collected a small number of insects from roadside morning glory flowers in the Cameron Highlands, a relatively cool locality in peninsular Malaysia.…”