What is eating our aruncus leaves?

[Eric Hardy]

What is eating our aruncus leaves? It only occurs low down and the upper leaves are fine and healthy. Could it be earwigs again? There is no sign of any ceature on the leaves.



Eric H

[ideasguy]

Thought perhaps Vine weevil
Heres a few links:
http://books.google.co.uk/books?id=pax_eOq8Q0oC&pg=PA156&lpg=PA156&dq=vineweevil+aruncus&source=bl&ots=dnwP9sObUC&sig=yfHuCTMFiTvTRulBm052Z5hQIxc&hl=en&ei=-tooSqSQOIfUjAfM4v3mCg&sa=X&oi=book_result&ct=result&resnum=1
Says the vine weevil Grubs Like munching the roots of astilbe and Aruncus
Doesnt say about the leaves though.


http://www.gapphotos.com/imagedetails.asp?imageno=135094
(you guys could do much better than that!)

http://www.hortsource.com/Insectpagesbk/InsectsPerennials.htm

Heres another suggestion:
http://www.gardenerscorner.co.uk/forum/showthread.php/caterpillar-butterfly-14929.html?s=b436c3b277be0dacdef6585e155c3c5d&
Into the thread I read:

Last night, I had to squash a number of sawfly larvae (like very small green caterpillars) that were making a meal of my aruncus sylvestris. Now they're the ones which need a "zero tolerance" policy!

[NightHawk]

What variety of Aruncus is it Eric?

I'm asking because I've been having a surf about and some reports I've found state that certain varieties of Aruncus deter specific pests.  For example: Aruncus aethusifolius 'Dwarf Goat's Beard' deters slugs.  Although slug damage hasn't been determined in your case, it indicates there could be a specific insect that is affecting yours.

Laurie.

[Eric Hardy]

Thanks Laurie.

We have had this plant for years and I think it is Aruncus dioicus (goat's beard). It is about 4 ft 6 ins high with a spread of about 6 feet. The spikes are about 5 ft 6 ins to 6 feet tall but aren't fully out yet. It fits the description in the RHS A - Z. Here are two pictures I took in July 2002 with a little 2 mega pixel Olympus.





I went out to have another look while composing this reply. I missed them the first time I looked (I didn't have my reading glasses on  ) but this time I discovered the little pests and have taken a picture for you. They are tiny and only about 1/4 inch long. Nice, aren't they?  Are these saw fly larvae and if so have you any idea of what to do about them?



Eric H

[Eric Hardy]

Heres another suggestion:
http://www.gardenerscorner.co.uk/forum/showthread.php/caterpillar-butterfly-14929.html?s=b436c3b277be0dacdef6585e155c3c5d&
Into the thread I read:

Last night, I had to squash a number of sawfly larvae (like very small green caterpillars) that were making a meal of my aruncus sylvestris. Now they're the ones which need a "zero tolerance" policy!

Sorry George, I missed your earlier reply.  I think they are probably saw fly larvae. I wonder what "zero tolerance" means? Squashing? Spraying?.

Edit: 3:30 pm. I have just been outside and taken off a few leaves. The plant can stand it. Can't do any more - flaming June has gone and it has just started to rain. At least no watering needed tonight

Eric H

[NightHawk]

Are these saw fly larvae and if so have you any idea of what to do about them?
Eric H

I think you're correct there Eric.

The skeletal pattern that's being left on your leaves with just the veins remaining is a characteristic feeding pattern of the sawflies larvae.

I've found a link on the BBC Gardening Website which gives more info on them.  The solution to get rid of them, as you will see, is chemical.

I hope this helps.

Laurie.

[Eric Hardy]

Thank you Laurie. I have looked at the website. I am not keen on using chemicals but that may be the only way in the long run. For the moment  I have removed as many of the affected leaves that I can see and I will keep an eye on it. The plant is large with lots of foliage and you hardly notice that I have removed any. Luckily most of the affected leaves were lower down.

Eric H

[NightHawk]

We're not keen on using chemicals either Eric.

You've always got the option of doing the job manually though.  Regular visual inspections and rub any larvae off by hand.

Of course, if you have many large shrubs that are being affected then that would be a mammoth task.

It comes down to personal choice on how you want to tackle this problem.

Good luck anyway. 

Laurie.

[Eric Hardy]

I am pleased to report that the aruncus seems to have recovered from its sawfly lava infestation. I caught it just in time.







Eric H

[ideasguy]

What a magnificent combination.
I REALLY like that Eric.

In my garden, Aruncus is as tough as old boots, but I have trouble with the slugs at my delphiniums. They tend to be short lived.
Do you have much trouble growing them? From the looks of those photos it seems not 

Is that Hydrangea petiolaris in the background?

[Eric Hardy]

Thank you very much George.

That particular delphinium is quite old and has survived the slugs. We have several growing at the moment but occasionally a slug decides to nibble a tender stalk when they are young  . That of course is fatal for the plant, I would prefer it if they nibbled the leaves. Anthea usually grows four or five plants from seed each year to replace ones that disappear.

Yes indeed, that Hydrangea petiolaris grows over and conceals our old stable. Here it is a bit closer to.





Eric H

[ideasguy]

Nice photos, Eric. I can use those in the Master Database if its OK by you.

Anthea is quite a gal, isnt she!
I raised Delphiniums from seed way back when I started gardening.
I sowed the seed outdoors.
I really do believe in beginners luck, particularly in gardening. I marked the area with a ring of sticks.
Up in the chosen area came a very good hit of Buttercups (and fortunately, some delphiniums).
I have also wryly observed that when you grow some seed in the open, nature will throw up weedlings which are very similar to the seedlings, only much more vigorous of course.
In this case it was Buttercups. Needless to say, as a beginner, I didnt know what delphinium seedlings looked like until they reached a more distinctive stage. As I recall, the buttercups looked rather similar to the Delphiniums. By that time I had a heck of a job removing the deep rooted Buttercups!
The beginners luck helped the seedlings survive!

I've 3 packets of seed sown in the greenhouse this year. So far only two seedlings - I pricked them out and potted them up last night. (No buttercups  )

How quick does the ones Anthea grows germinate? Does she get a good hit rate?

[Eric Hardy]

Nice photos, Eric. I can use those in the Master Database if its OK by you.

As I said before, George, you are welcome to use any of my photos any time you like. If you need them larger let me know and I can email them to you.

How quick does the ones Anthea grows germinate? Does she get a good hit rate?

Anthea gets a pretty good hit rate with her delphinium seeds. I have consulted her and she says they sometimes take a long time to germinate, possibly four or five weeks and sometimes more. so perhaps more will appear for you. She normally collects the seed for use the following year. The interesting thing is that over the years they seem to revert and instead of the tight clusters of flowerlets the flowerlets seem to be more dispersed on individual short stalks. We like the effect but they would not win prizes at a flower show.

Apart from scattering a few shirley poppy seed we never plant seeds in the open soil these days. With our reduced gardening hours (and lack of stamina) we would have difficulty in preventing the seedlings getting choked. I can see why in your early days the buttercup/delphinium mix was a bit confusing 

Eric H

[ideasguy]

Thanks for Antheas info on length of time for the Delph's to germinate. When I potted up the two seedlings I also found a new seedling nestling under one of them, so they are still germinating. I potted it as well, even though it was at cotyledon leaf stage.

We shall see
if there be three
(Anon - wishes to remain as)

As for lookalke weedlings and seedlings, I think that would make a good topic for discussion!
I sowed seeds of Californain poppies in the greenhouse this year. When I planted them out I noticed some very similar little seedlings in the garden.
Unless of course they ARE poppies, self seeded from the last batch I had