Rodriguezia bahiensis Rchb. f. : biologia floral, polinizadores e primeiro registro de polinização por moscas Acroceridae em Orchidaceae

Abstract

-(Rodriguezia bahiensis Rchb. f.: floral biology, pollinators, and first record of Acroceridae fly pollination in Orchidaceae). Rodriguezia is distributed throughout Tropical America, comprising nearly 40 species, most of them little known regarding floral biology and pollination. Rodriguezia bahiensis is endemic to northeastern region of Brazil, it bears flower features that suggest pollination by butterflies and bees. However, the population studied is associated to a large array of visitors, including bees, butterflies, moths, hummingbirds and Acroceridae flies, the last group being for the first time recorded as pollinators in Orchidaceae. Flowers offer low quantities of nectar as reward that together with the nectar guides imitating pollen suggests the occurrence of a combined system of reward and deceit of pollinators. Though population studied is associated with a high number of visitors, natural fruit set is low (6.57%) may be due to high frequency of pillagers and possible self-incompatibility in the studied species.Key words -fly pollination, generalist Orchidaceae, Rodriguezia, Philopota RESUMO -(Rodriguezia bahiensis Rchb. f.: biologia floral, polinizadores e primeiro registro de polinização por moscas Acroceridae em Orchidaceae). O gênero Rodriguezia distribui-se pela América Tropical, com cerca de 40 espécies, pouco conhecidas quanto à biologia floral e polinização. Rodriguezia bahiensis é endêmica ao Nordeste do Brasil e apresenta flores com atributos associados às síndromes de psicofilia e melitofilia. No entanto, a população estudada está associada a uma ampla guilda de visitantes florais incluindo borboletas, abelhas, mariposas, beija-flores e moscas Acroceridae, este último grupo registrado pela primeira vez atuando como polinizadores em representantes de Orchidaceae. As flores apresentam néctar como recurso, encontrado em baixa quantidade, o que em conjunto com a presença de guias de néctar imitando pólen sugere a ocorrência de um mecanismo de polinização combinando recompensa e engano. Embora a população estudada esteja associada a uma larga guilda de visitantes, a formação natural de frutos da população é baixa (6,57%), o que pode estar associado à alta frequência de pilhadores e possível auto-incompatibilidade na espécie estudada.Palavras-chave -Orchidaceae generalista, polinização por moscas, Rodriguezia, Philopota

Pollination ecology of Rodriguezia granadensis (Orchidaceae)

“…Thirty six percent of the R. granadensis flowers possessed nectar, at a high sugar concentration (33%). Nectar volumes were greater than those observed in Rodriguezia bahiensis with only 0.4µl and 16.5 % of sugar (Carvalho & Machado 2006). R. bahiensis is known to be pollinated by flies and visited by bees.…”

Evolution of Philopotinae, with a revision and phylogeny of the New World spider fly genusPhilopota Wiedemann (Diptera, Acroceridae)

“…Adults of ∼ 20 genera have long, modified mouthparts used for nectar feeding, whereas the remaining ∼ 35 genera probably do not feed as they have reduced or even absent mouthparts (Schlinger, ). Many species are specialized pollinators and are usually collected on or near flowers (Schlinger, ; Goldblatt, Manning & Bernhardt, ; Gilbert & Jervis, ; Potgieter et al ., ; Pujol‐Luz, ; Barbola et al ., ; Carvalho & Machado, ; Borkent & Schlinger, , b).…”

“…Wing venation, for instance, is strikingly more variable within Philopota than within any other acrocerid genus, with multiple reductions and deviations from the plesiomorphic, complete wing venation of Acroceridae. Moreover, species of Philopota are ecologically very important as flower visitors and even as pollinators (Pujol‐Luz, ; Carvalho & Machado, ), and some species are amongst the most abundant spider flies in the Neotropics. Nonetheless, the genus has never been revised, and its most recently described species is Philopota flavolateralis Brunetti, .…”

Pollen loads and pollen diversity on bodies of Eulonchus tristis (Diptera: Acroceridae): implications for pollination and flower visitation

“…Two undetermined species of Philopota Wiedemann carry pollinia and are important pollinators of the Brazilian orchid Rodriguezia bahiensis Rchb. f. (Orchidaceae) (Carvalho and Machado 2006). No studies have been made of pollen carried by acrocerids in North America, although some genera (e.g., Eulonchus Gerstaecker) are locally abundant on flowers (Cole 1919;Schlinger 1960) and exhibit behaviours that show constancy to particular plant species (Borkent and Schlinger 2008).…”