Flowering phenology of Mouriri guianensis (Melastomataceae) and its interaction with the crepuscular bee Megalopta amoena (Halictidae) in the restinga of Lençóis Maranhenses National Park, Brazil

Abstract

Mouriri guianensis is a Brazilian endemic plant species distributed throughout the Amazon forest, Caatinga, Mata Atlântica and Cerrado domains, extending northward into Venezuela. The aim of this study was to describe the flowering phenology, floral biology and visitors associated with M. guianensis, highlighting the crepuscular bee species Megalopta amoena. Mouriri guianensis flowers from September to March. The flowering, the details of floral biology and the activities of floral visitors were observed for ten individual plants in December 2013, January-March 2014, September-December 2014 and JanuaryMarch 2015. The flowering peaks occurred in December 2013 and in November-December 2014. Bees were collected in January and February 2015. A total of 86 individuals belonging to six bee species were recorded visiting the flowers, with Xylocopa cearensis making more than one-half of the visits (60%), followed by Melipona subnitida and Megalopta amoena with 21.17% and 9.41% of the visits, respectively. The visitors showed activity peaks between 5:00 and 6:00 AM (66.27%). Buzz pollination was their predominant behavior. Megalopta amoena used its jaws to open the pore and the anther gland. Melipona subnitida used parts of the glands to seal the entrance to the colony. The visitors, except for Augochlopsis sp. and Trigona sp., are pollinators of M. guianensis. Plants having an extended anthesis can attract visitors both day and night. In this study, we present an example of a crepuscular pollination system. We suggest that blooming at twilight is a strategy used by the plant to escape unsuitable visitors. KEYWORDS: Pollination, insect-plant interaction, floral oil, crepuscular foraging. Um total de 86 indivíduos de seis espécies de abelhas foi registrado visitando as flores com Xylocopa cearensis realizando a maioria das visitas (60%), seguida por Melipona subnitida e Megalopta amoena com 21,17% e 9,41%, respectivamente. Os visitantes mostraram picos de atividade entre 5:00 -6:00 h (66,27%). O comportamento predominante foi o de vibração. Megalopta amoena utilizou suas mandíbulas para romper os poros da antera e glândula. Melipona subnitida utilizou partes das glândulas para a vedação da entrada da colônia. Os visitantes, a exceção de Augochlopsis sp. e Trigona sp., são polinizadores de M. guianensis. Plantas com longos períodos de antese podem atrair visitantes diurnos e noturnos. Aqui demonstramos um exemplo de sistema de polinização crepuscular, sugerindo que o fato florir durante o crepúsculo é uma estratégia da planta para escapar de visitantes inoportunos. PALAVRAS-CHAVE: Polinização, interação inseto-planta, óleo floral, forrageamento crepuscular. Flowering phenology of Mouriri guianensis (Melastomataceae) and its interaction with the crepuscular bee Megalopta amoena (Halictidae) in the restinga of Lençóis Maranhenses National Park, Brazil ACTA Fenologia da floração de

Is Nocturnal Foraging in a Tropical Bee an Escape From Interference Competition?

“…Ours is the first study of Megalopta to analyze data minute by minute and separate observations by flower to explicitly test for overlap, although studies of other Megalopta species show results similar to our Fig. 2 ( Franco and Gimenes 2011 , Krug et al 2015 , Oliveria et al 2016 , Cordeiro et al 2016 ).…”

“…Because flowers produced little nectar after midnight ( Kays et al 2012 ), it is unsurprising that overall visitation rates were low in the morning. Other species of flowers that open late at night are visited by Megalopta more frequently in the pre-dawn foraging period ( Roulston 1997 , Franco and Gimenes 2011 , Smith et al 2012 , Krug et al 2015 , Oliveria et al 2016 , Cordeiro et al 2016 ).…”

“…We used observations of the Neotropical, night-flying bees Megalopta genalis and M. centralis on flowers of the balsa tree, Ochroma pyrmalidae , to test if escaping interference competition structures nocturnal foraging . Megalopta (Halictidae) are solitary or weakly social (typically 2–3 colony members) bees that forage from both diurnal flowers that remain open past sunset or open before sunrise, and flowers with nocturnal anthesis ( Janzen 1968 , Roulston 1997 , Hopkins et al 2000 , Wcislo et al 2004 , Kelber et al 2005 , Franco and Gimenes 2011 , Smith et al 2012 , Krug et al 2015 , Oliveria et al 2016 , Cordeiro et al 2016 ). Megalopta are generalist foragers, with 64 species of pollen recorded from nests at a single site, an active nesting season of ∼9 months and opportunistic shifts among pollen sources based on availability ( Smith et al 2012 ).…”

Light intensity regulates flower visitation in Neotropical nocturnal bees

“…As far as we know, only four studies [46][47][48][49] have evaluated the effects of temperature on the activities of nocturnal bees. Two of these studies 46,49 found no effect of temperature, while one study suggests that temperature positively affects bee activity, but only above 25 °C and combined with lower light intensity 47 . The fourth study found that higher temperatures have a moderately negative effect on activity 48 .…”

Visual ecology of nocturnal bees: how light intensity affects foraging activity in cambuci, a neotropical Myrtaceae

“…As far as we know, only four studies (Shelly et al 1993, Gottlieb et al 2005, Franco and Gimenes 2011, Oliveira et al 2016 have evaluated in some way how temperature determine nocturnal bees activity. Two of them (Shelly et al 1993, Oliveira et al 2016 have found no effect of temperature, one has implicated that temperature affects positively bee activity over a range of 30°C (Gottlieb et al 2005) and another has found that temperature has a moderate negative effect over activity (Franco and Gimenes 2011). Three of them have also suggested light intensity as a factor affecting bees activity (Shelly et al 1993, Gottlieb et al 2005, Franco and Gimenes 2011).…”