Something is eating the ivy that covers a wall of my house. Is it a disease or is there something hiding that eats the leaves? And what can I do to heal my ivy?
You can see an example of the damage to the ivy in the top row of pictures:
Click on all pictures for larger view.
Perhaps unrelated, but another plant is having the same 'symptoms', but with added yellow discolouration:
Well it looks like adult vine weevil damage. The adults cause these holes by eating on the plants at night, but its the grubs that cause the most damage. They particularly like pots, so assuming these two plants (looks like Euonymus in the last picture) aren't in pots, then you may have an infestation in pots elsewhere. They do also live in soil though.
Treatment is difficult - pots can be treated successfully with a nematode solution (ordered online, google Nemesys and select vine weevil nematodes) or a chemical drench, but nematode solutions do not work well on open ground which is heavy or dry, and must be applied when the temperature and time of year is right. Thiacloprid is a chemical which can be applied as a drench to soil in containers, but is not suitable for use in open ground. Two treatments which contain this and which are used as a drench are Scotts Bugclear Vine Weevil Killer, or there's a Bayer one too.
Note that the adults don't usually kill plants - the larvae in the soil, though, will eat through roots and kill pot plants particularly. The only 'organic' way of tackling the adult beetles is to go outside at night with a torch and a bucket of water, shake the stems and catch the beetles, or pick them off by hand. This assumes that you're not seeing slug or snail trails all over the ivy though - I don't see any in the pictures. If you are, slug/snail damage might be the problem, given the very wet weather we've all been having this year and the resulting explosion in the population of these creatures.
