Pumpkin Pollination – Which Bees?

It was because of my vegies that I made my initial and very tentative enquiries into bees. Five years of planting pumpkins and zucchini and not a single fruit on any of my plants. No bees in sight, ever! It was a no brainer as to what I needed.

Ray Berkelmans, Gold Coast

Having done some reading I was dead keen on starting with native bees. If I had to have bees, it may as well be native bees, not honey bees. The idea of getting stung did not appeal to me at all! Unfortunately for me, the call to the honey bee club poured cold water on my idea of native bees for this job. I was told then, and many times since then, European veggies need European honey bees to pollinate them. The flowers, especially in the cucurbit family (which include the pumpkins, melons, zucchinis etc.), are too big for native bees. They are better suited to native, smaller flowers. I duly joined the club and found honey bees so interesting and stimulating that I soon forgot about pumpkins and zucchini: bees were now the main game! And now, quite a few years later, things have not changed… except for one small detail….

Pumpkins, like most cucurbits, seem to go for quality over quantity in their pollen. Their pollen has a very high protein content, is low in number (relative to wind pollinated plants) and is sticky. Wind plays NO role in their pollination. That means 100% of their pollination is up to insects. A report by the Australian Rural Industries Research and Development Corporation (RIRDC), “Pollination Aware: The Real Value of Pollination in Australia” (August 2010), quantifies the pollination services of honey bees for the first time. According to this report 100% of all commercial pumpkin, melon and squash crops in Australia are pollinated by honey bees. It would be easy to conclude that no other insects, let alone native bees, play any role whatsoever in cucurbit pollination, right? Wrong! As is so often the case, the truth is always more complex than the science would suggest. These days I keep honey bees as well as native bees in my back yard. And what do I find in my pumpkins? Native bees! Honey bees too, but by number, way more native bees than honey bees. Not just once, most days. Not a few, I mean lots of native bees. Not just female flowers, male flowers too. So, who’s doing the job here? Let’s hear it for the natives, our unsung heroes!