Leafcutter Bees for Summer Pollination

leafcutter beeAdvice from Darren Morgan –
Now summer is here, and you’re sitting back enjoying the fruits – literally – of the labor your mason bees did for you this spring: cherries, and blueberries, and fresh plums and peaches.  It’s a great time to watch the garden develop, and ponder those inevitable western Oregon veggie questions:  is the first cucumber going to set before my lettuce bolts? and am I really going to get any melons this year?

While you can’t do anything about the inconsistencies of our summer weather, you can improve your odds of successful pollination and fruit set in your squash, melon, and cucumber plants by encouraging and hosting leafcutter bees.  These solitary native bees are late emerging pollinators, waiting until temperatures settle into the 80 degree range to finish incubating – perfect timing for your vining veggies.

Here are a few tips to encourage a good population of these gentle and beneficial insects:

*Leafcutter bees need holes to nest in, and they usually don’t make their own.  You can host them in tubes, just like your mason bees, but they prefer a smaller diameter (around 6mm).  You can use your existing mason bee house – remove your filled and capped tubes to the shade and protection of a garage or storage shed, and replace them with smaller tubes.  If  your mason bee house is not near the vegetable garden, get or make another shelter to install there to put your tubes in – like mason bees, leafcutters don’t like to travel too far.
*Leafcutters also need nest building material.  Unlike mason bees, leafcutters use cut up leaf material to seperate the egg chambers.  They prefer leaves that are not too coarse, fibrous, or thick, often using rose, ash, or lilac leaves. The damage from their activity is only cosmetic on otherwise healthy plants, but you might want to cap any freshly cut rose canes (they will sometimes bore away the inner pith to a depth of several inches and nest in there, leaving brown cane tips throughout your rose garden).

*Be careful about pesticide use.  Use less toxic and shorter duration insecticides when necessary, and spray in the evening after bees have gone home for the night.

See us for all your pollinator needs – honey bee supplies, native bee nesting tubes, butterfly host plants, and more!

Photo:  www.crownbees.com