Hi all.  I have a dilemma on my hands.  My dahlias are being savaged by a mysterious pest. It is not slugs, I've checked for caterpillars and cannot find any, does anyone know what it could be?  Holes are being left in the leaves, some even savaged, the holes look like the wings of a lacewing.  Thanks


  • sotongeoffsotongeoff Posts: 9,806

    A guess -not slugs or caterpillars you say, bit early for earwigs they usually go for flowers-have you any pigeons that visit the garden?-they do go for brassicas-is the damage overnight or in the daytime?

  • mdw84mdw84 Posts: 105

    I have the occasional pigeon that visits the garden, but not where the dahlias are, they tend to stay at the bottom of the garden where the feeders are and that way they are a safe distance from the cat and English BullMastiff.  I'm not really sure when the damage happens, I've just noticed it over the last couple of weeks, if it's any help the same is happening to the delphiniums nearby.

  • BobTheGardenerBobTheGardener LeicsPosts: 6,357

    Delphiniums and dahlias are probably slugs and snails favourite snacks, so double-check for them.  They don't always leave obvious trails.  When you say the holes are like the wings of a lacewing, do you mean the structure is intact, but the green material between the veins is being eaten?  If so, it could be a sever leaf miner attack.  A photo would really help.

    A trowel in the hand is worth a thousand lost under a bush.
  • kate1123kate1123 Posts: 2,815

    I have just been out and done a slug/snail run, one of my dahlias had 3 snails on it munching away, but not any longerimage

    Have you checked for cutworms?

  • mdw84mdw84 Posts: 105

    Leaf miner sounds more like it, never heard of cutworms (I must research them)

    BOB - yes the structure is intact but green material is being eaten,that is some of the damage, the other damage looks like caterpillar but no signs.

    It's definitely not slugs or snails, there have been signs but I do checks am and pm, and use slug bait and traps.

  • BobTheGardenerBobTheGardener LeicsPosts: 6,357

    If it is insect damage ike leaf miners or cutworms/caterpillars and you are not averse to non-organic controls, give them a spray with a systemic insecticide which will be absorbed and spread throughout the plants.  Provado ultimate bug killer is a good one.  Systemics are the only things that will work against miners, which eat the leaves from the inside, so contact insecticides are useless againt those.

    A trowel in the hand is worth a thousand lost under a bush.
  • mdw84mdw84 Posts: 105

    Thanks all, one final thing, would it be worth removing the damaged leaves?

  • mdw84mdw84 Posts: 105

    Latest update.

    I've been out this morning and found out what the problem is, "earwigs".  I shouldn have thought more about it really, as at the weekend I found a nest of them in a solar light near the affected plants.  I have removed the leaves and the solar lights as they all had earwigs in them.  Any ideas of how to keep these pests away?

  • sotongeoffsotongeoff Posts: 9,806

    So one of the things I discounted might be the culprit-the classic remedy is an upturned flower pot filled with straw atop a cane-they hide in there during the day as they are nocturnal-so just empty them out and do with them what you will-they are not all bad and do some good in the garden

    It wont get rid of them but at least it gives you some control

  • mdw84mdw84 Posts: 105

    They seem to be in abundance this year, I was digging over ther garden yesterday and there was a nest under my pieris.  In the two solar lights near the dahlias, both had nests in so they been moved into the wildlife garden.  Also the amount of red ant nests in my garden in unbelievable, a total of 6 so far this year.


  • Hi all

    I am a new member so if the blog below has been said before I apologise 

    i have the same problem with snails and slugs but I advice you all ,if you have any fauna growing in pots you need to check actually under the pot !!!,as slugs and snails will crawl under them ,also a great hiding place is under any rims around the top of the pots ,I regularly find several snails and slugs residing there over the day just run your fingers around the underside of the rim and you will easily locate them ,wear rubber surgical cloves if you are a bit Squamish lol.

    one last note,you need to look very carefully as most people tend to look for rather large slugs and snails but on very close inspection you will find juinior slugs/snails no bigger than a couple of millimetres and they will be the ones munching away without you even seeing them,then you will claim you have no slugs or snails but you have !!!

    happy days 

  • B3B3 Posts: 4,993

    I would leave the solar lights. At least you will know where to find them! Sounds like they are working the same as a straw trap.

    In London. Keen but lazy.
  • Grait1976Grait1976 Posts: 1

    imageI found this Beatle eating my dahlia leaves

  • I am having the same problem as mdw84 with my dahlias in pots & a nearby fuschia it is a real mystery two weeks ago they were all looking really good and now they look devastated I have looked at verticullium wilt and have found a green shield bug on one of the plants but I'm not sure this is the culprit I have just sprayed with with washing up liquid mixed with tea tree oill which works effectively on greenflys etc but the plants look so poor now they don't look like the will survive any more help please!!!

  • I had some problems with earwigs and after doing some research I found that a beer trap filled with cooking oil and soy sauce mixed instead of beer has worked well with the trap having loads of the little blighters in every morning. My dahlias have been virtually untouched since using this method.



  • Mark56Mark56 Berkshire, UKPosts: 1,395

    Definitely works here too Jay, just make sure to take it up in the morning before the bees & butterflies are attracted image

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