The MGS Forum

Gardening in mediterranean climates => Pests and diseases => Topic started by: MikeHardman on May 13, 2012, 08:50:02 AM

Title: European chafer (Rhizotrogus majalis) - evening swarming
Post by: MikeHardman on May 13, 2012, 08:50:02 AM
Just reporting an observation...

Yesterday evening, shortly before dusk, there was a steady humming from one of my belts of cypress (Cupressus sempervirens). It was similar to the buzzing from a large number of bees (eg. when you get a large number in a citrus grove), but a slightly deeper tone. As I approached the trees, I could see dozens of flying insects, bigger than bees. They were just flying around the branches, somewhat manically, I thought. They largely ignored me. It was frustrating trying to see what they were because they did not seem to be landing.

Then, by following one or two, I happened to find a female, who was sitting on a stem nearby (a Pelargonium stem as it happened). A few males were scrambling to mate with her. I presume similar goings-on were happening in the branches of the cypresses. I could see the insects were beetles, and from their shape and colour they looked like European chafers (Rhizotrogus majalis); about 15mm long - much smaller than the cock chafers many gardeners will be familiar with. The evening swarming behaviour (http://en.wikipedia.org/wiki/European_chafer) is also correct for this species.

These critters feed mainly on the roots of grasses (http://pest.ceris.purdue.edu/pest.php?code=INBPAGA). Since I cultivate no grasses, I do not consider them a pest. Obviously, other folks may have a different opinion!

If I manage to get a photo, I'll add it here....
update 20may12: success (a tad out of focus, mind)