Black beetle on irises

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Alice

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Black beetle on irises
« on: May 21, 2015, 08:43:32 AM »
These beetles has been decimating our lovely Iris germanica flowers. They also affect other flowers but seem to love irises; I have picked off 16 from a single flower in one go but then others are back to take their place! I think they eat the pollen but they devastate the whole flower. Id please and how do I deal with the problem.
Amateur gardener who has gardened in north London and now gardens part of the year on the Cycladic island of Paros. Conditions: coastal, windy, annual rainfall 350mm, temp 0-35 degrees C.

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JTh

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Re: Black beetle on irises
« Reply #1 on: May 22, 2015, 12:31:06 PM »
John J showed a black beetle on his irises a short while ago, it was identified by Miriam as Oxythyrea funesta, which seems to be very much like yours, Alice. There were many beetles looking identical in Halkidiki at the same time, I took a couple of photos, one on a wild pear flower, the other on a Cistus salvifolius, but they were everywhere. I have never seen this many before, I wonder if this was the result of a very wet winter?

The hairs are quite prominent in young beetle, easily seen in the first picture. I have no idea how to get rid of them or if it is at all possibe, but I found a link to a Hungarian company selling traps. http://www.csalomontraps.com/4listbylatinname/pdffajonkentik/oxythyreafunestaang08.pdf


_Z130246 Scarab beetle attack.jpg
by Jorun Tharaldsen, on Flickr


_Z130229 Cistus salvifolius with Oxythyrea funesta.jpg
by Jorun Tharaldsen, on Flickr
Retired veterinary surgeon by training with a PhD in parasitology,  but worked as a virologist since 1992.
Member of the MGS  since 2004. Gardening in Oslo and to a limited extent in Halkidiki, Greece.

Alice

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Re: Black beetle on irises
« Reply #2 on: May 23, 2015, 07:10:22 AM »
Thanks, Jorun. They do look like yours and the ones in the link. I had missed John's post. I have seen them in the past, mainly on roses but, like you, have never seen them in such numbers. They seem to bore into the heart of flowers and completely ruin them. I noticed today that they are also having a go at our Scabiosa cretica. At the moment I am picking them off by hand, which doesn't seem to be very effective. Next year I will try the trap. I wondered if, in the short term, I could spray the irises with something to protect them.
Amateur gardener who has gardened in north London and now gardens part of the year on the Cycladic island of Paros. Conditions: coastal, windy, annual rainfall 350mm, temp 0-35 degrees C.