VINE WEEVIL LARVAE

It's a fact of life that a gardener's lot is to battle not only the elements but pests and diseases that invade our beloved gardens.  I wondered why my beautiful Japanese Maple, Acer palmatum 'Orange Dream', that cost me quite a few £s, had died over winter while the one right next to it, Acer palmatum dissectum 'Ornatum' had thrived (at least, so far).  I thought it was just too windy, or too cold, or too something over the months since I bought it and even in its first year its leaves began to wither.  It had no chance; inspecting the compost today before risking planting anything else in it, I discovered dozens of tiny white grubs.  They are, I gather from my research on the internet, the dreaded Vine Weevil larvae.

 

Vine Weevil pupa

The poor thing in the above image looks as if it's begging for mercy, but I had none I am afraid. I want to use the compost for growing other things or at least for putting it on my garden border but I couldn't risk spreading the vine weevil larvae which eat the roots of plants and kill them unseen.  There were so many that I couldn't pick them all out so I despatched them in a way which I know some will consider most cruel, but no more cruel and efficent than spraying chemicals all over them - I poured litres of boiling water into the infected container.   That killed them and ensured, to a great degree, that the compost was free of pests and diseases, at least for now.

 

Vine Weevil pupa

 

Vine Weevil pupa

More information here at the RHS webpage on the Vine Weevil where you can see an image of the mature insect. 



If you wonder why I, and many other gardeners, dread the Vine Weevil so much it is because, in my case, this insect, many years ago, before I knew they existed, cleared out the whole of my collection of wonderful fuchsias over one winter.  I had overwintered them indoors and found, at the time they should have been coming out of dormancy, that they had no roots whatsoever.  The plants were just sitting in their pots, looking dormant, as if there wasn't a thing wrong.  And that's the problem, the larvae can kill your plants and you won't even know it's happening.  Apparently, they also like begonias and heucheras, and, of course, my Japanese Maple!  I also think it is possible that the weevil despatched my lovely Clematis alpina 'Constance' as that died over one winter and was rootless. 



All you can do is keep a look out for the mature beetle and check the compost in your containers from time to time.  The larvae are very white/light in colour and can easily be seen.  The trouble is, there can be so many.




Update: 14 May 2016




I discovered that vine weevil larvae have destroyed a free-standing trough full of everfruiting strawberries.  I wondered why the plants weren't doing very well.  The strawberries aren't everfruiting now! In the above photographs you can see how the larvae pupate into the adult (evil) weevil. 



Vine weevil larvae before pupation 07052016

The adult vine weevil below:

(c) Royal Horticultural Society