The tomatoes are flowering. That’s a good start, but pollination has to occur to convert those flowers to fruit. Many plants use food in the form of nectar to lure pollinators to the flowers, which then pick up and distribute pollen on the way in and out of the dining room. Tomatoes are one of the 20,000 or so plant species that evolved a different arrangement. They offer pollen itself as food and to get it insects need special skills. They must vibrate tubes inside the flower so violently that pollen explodes out – onto the bee and the female flower parts. It’s called buzz pollination and big fat furry bumblebees are experts. Honeybees can’t do it at all.
Our local specialists in buzz pollination are native bees. There are some 2,500 species of bees that call Australia home, though that figure is a bit rubbery as only 1600 have been described and named. Dr Katja Hogendoorn, from the University of Adelaide, who has named four of them herself, says the Sydney region is home to “some quite spectacular species of buzz pollinating bees, including quite a few of the blue-banded bees, the teddy bear bee, and the gold and green nomia bee.”
Buzz pollination captured on video and played at normal speed sounds like a usual bee buzz, interspersed with a turbo-charged buzz like a bee-world jackhammer. When the video is super-slowed it shows that the sound is made when a bee head-bangs the flower at a speed of 350 times a second.
In commercial tomato glasshouses buzz pollination is faked using a kind of re-purposed electric toothbrush called a vibrating wand. In research by Melissa Bell, conducted at the University of Western Sydney-Hawkesbury, blue-banded bees were found to be just as effective pollinators as the laboriously applied vibrating wand, and both methods produced fruit that was rounder, heavier and larger than the controls, and more of it.
Invite bee headbangers around to your place to improve the quality and quantity of harvests of not just tomatoes, but also eggplant, zucchini, pumpkin and blueberries, which are all buzz pollinated. Native bees are solitary and around half of the known species, including blue-banded bees, build their nests in the earth. A single hole in the ground might lead to a subterranean apartment block housing up to 100 single-dwelling bees. So leave some bare soil unmulched, especially by paths or between stepping stones. Alternatively build a bee brick house from powdery clay (details at www.aussiebee.com.au). Other local bees live in holes of various diameters in sticks, and these bee hotels can be made or purchased.
Buzz pollinating native bees don’t produce honey, but gardeners find that the rewards of having them visit are sweet.
One more thing:
Katja Hogendoorn’s latest research is in using honeybees as ‘flying doctors’, delivering biological controls to blossom to prevent fungal attack. The method has been proven effective in strawberries and offers an alternative to commercial strawberry growers’ weekly antifungal sprays. Next up – cherries, summer fruit, pear and apple. To find out more: facebook.com/Beesasflyingdoctors