The MGS Forum

Gardening in mediterranean climates => Pests and diseases => Topic started by: JTh on July 02, 2014, 11:29:42 PM

Title: Is this locust eating the leaves on my roses?
Post by: JTh on July 02, 2014, 11:29:42 PM

I still haven't solved the problem of who is eating the leaves on my rose bushes, but a few days ago I found this giant locust, which seems to be a female Anacridium aegyptium (Egyptian tree locust, at least 7 cm long) sitting on a partly digested rose leaf. I wonder if this is the culprit? If so, is there any dererrent, would a spray with neem oil make the rose leaves less tempting?

(https://farm4.staticflickr.com/3923/14374781727_86f36420ac_n.jpg) (https://flic.kr/p/nUfvNg)
_6291714_Anacridium aegyptium.jpg (https://flic.kr/p/nUfvNg) by JorunT (https://www.flickr.com/people//), on Flickr

Title: Re: Is this locust eating the leaves on my roses?
Post by: David Bracey on July 03, 2014, 06:58:01 AM

Do you have a pic of the leaf damage...it may vine weevil , chafer etc ...?

Title: Re: Is this locust eating the leaves on my roses?
Post by: JTh on July 03, 2014, 08:47:34 AM

You are right, David. When I looked more closely, I did find leaves indicating that the damage is caused by larvae of chafers, and between two leaves stuck together with a fine web, I detected this larvae (top photo). It was about 7-8 mm long, pale, small head, very short legs. It didn’t like to be disturbed and was moving very rapidly, so it was difficult to get a proper photo of it. The next shows the leave where I found it, and the last one of a leaf in an advanced stage.  At the end only the nerves are left.

I don’t see the adult chafers on the roses now, but there are plenty of large, green metallic looking chafers having a feast in our pear tree.

(https://farm6.staticflickr.com/5560/14563520265_6268f6b97c_n.jpg) (https://flic.kr/p/obVRbZ)
_7031845_Offending larva.jpg (https://flic.kr/p/obVRbZ) by JorunT (https://www.flickr.com/people//), on Flickr

(https://farm4.staticflickr.com/3838/14560129831_64556b999f_n.jpg) (https://flic.kr/p/obCtke)
_7031859_Early leaf damage.jpg (https://flic.kr/p/obCtke) by JorunT (https://www.flickr.com/people//), on Flickr

(https://farm6.staticflickr.com/5570/14376891498_3e1c3e0cb3_n.jpg) (https://flic.kr/p/nUrjXC)
_7031860_Advanced leaf damage.jpg (https://flic.kr/p/nUrjXC) by JorunT (https://www.flickr.com/people//), on Flickr

Title: Re: Is this locust eating the leaves on my roses?
Post by: JTh on July 03, 2014, 10:24:13 AM

I’m afraid I was too quick in blaming the chafers alone, at some closer inspection I discovered lots of larger larvae with orange heads and black markings, around 1.5 cm long. As far as I can see, they must be larvae of the sawfly, Arge ochropus. They probably cause more damage than anything else, greedy creatures!

(https://farm3.staticflickr.com/2909/14563060592_5b32048aac_n.jpg) (https://flic.kr/p/obTuxA)
_7031864_Arge ochropus .jpg (https://flic.kr/p/obTuxA) by JorunT (https://www.flickr.com/people//), on Flickr

(https://farm4.staticflickr.com/3842/14377265188_786fc84b30_n.jpg) (https://flic.kr/p/nUtf3y)
_7031868_Arge ochropus .jpg (https://flic.kr/p/nUtf3y) by JorunT (https://www.flickr.com/people//), on Flickr

Title: Photos of sawfly larvae, Arge ochropus
Post by: Alisdair on July 04, 2014, 07:40:18 AM

Amazing photos, Jorun!