A team of entomologists has captured Australian blue-banded bees’ unique approach to pollination – headbanging flowers up to 350 times a second.
The blue-banded bee Amegilla murrayensis. Image credit: Callin Switzer.
The team, headed by Harvard University scientist Callin Switzer, compared the pollination techniques of Australian blue banded bees with North American eastern bumblebees, which are commonly used overseas to commercially pollinate tomato plants.
“We compare buzz-pollination on Solanum lycopersicum (cherry tomatoes) by two bees that fill similar niches on different continents – in Australia, Amegilla murrayensis (blue-banded bee), and in North America, Bombus impatiens (common eastern bumblebee),” Mr Switzer and his colleagues wrote in a paper in the journal Arthropod-Plant Interactions.
While bumblebees grabbed the anther of the tomato plant flower with their mandibles before tensing their wing muscles to shake the pollen out, super slow motion footage revealed the blue banded bee from down under prefers a ‘hands-free’ approach.
The scientists found that by recording the audio frequency and duration of the bees’ buzz, they were able to prove the bee vibrates the flower at a higher frequency than North American bumblebees and spend less time per flower.
“We found that Amegilla murrayensis buzzes at significantly higher frequencies (350 Hz) than Bombus impatiens (240 Hz) and flaps its wings at higher frequencies during flight,” they wrote in the paper. “There was no difference in the length of a single buzz, but A. murrayensis spent less time on each flower, as B. impatiens buzzed the flower several times before departing, whereas A. murrayensis typically buzzed the flower only once.”
“High-speed videos of A. murrayensis during buzz-pollination revealed that its physical interaction with the flower differs markedly from the mechanism described for Bombus and other bees previously examined.”
“It was the first time the phenomenon had been observed,” said Dr Sridhar Ravi of RMIT University, co-author on the study.
With bumblebees not found on the Australian mainland, local greenhouse tomatoes are pollinated mechanically.
“Our earlier research has shown that blue-banded bees are effective pollinators of greenhouse tomatoes. This new finding suggests that blue-banded bees could also be very efficient pollinators – needing fewer bees per hectare,” said co-author Dr Katja Hogendoorn, of the University of Adelaide.
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Callin M. Switzer et al. Shakers and head bangers: differences in sonication behavior between Australian Amegilla murrayensis (blue-banded bees) and North American Bombus impatiens (bumblebees). Arthropod-Plant Interactions, published online December 1, 2015; doi: 10.1007/s11829-015-9407-7
