Many readers of my blog or twitter will know of my ongoing battle with vine weevils. Their population seems to have soared in recent years, and with the hugely devastating consequences that they can have upon plants, I’ve made them a number one enemy. However, whilst battling these foes, it is important to remember that our friends the bees need as much help as possible. And therefore, the use of compost containing vine weevil pesticide should be strictly avoided. (Honey, Bumble and Mason bee’s are all at risk – picture above).
It’s at this time of year that I start preparing the borders of my own garden, and clients, for that splash of winter colour. Cyclamen, ready to burst into flower during the bleak, cold months of the year are a particularly tasty morsel for vine weevil grubs. As are primulas and polyanthus which are so commonly used in the late winter and early spring season to provide some vital garden cheer. And with such plants providing an important palette of colour during grey and dismal weather, the importance of saving them is high. However, with fat, white vine weevil grubs chewing their way through root, after root, after root, the stunning winter display can quickly wither and fade to nothing and once the effects are seen above the surface, there is little that can be done to save plants.
But, far higher above the priority of a few plants, is the importance of bees. Without them, the entire human population is doomed, for pollination of our cereal crops, fruits, animal feeds, would all but halt. And I for one enjoy the blissful sound of a bustling worker drone on a quiet summer’s day as it gathers nectar for its hive. However, the use of neonicotinoid pesticide in vine weevil composts has been raised as a possible reason for ‘Colony Collapse Disorder’ in bees, and therefore should be avoided at all costs. Though not proven, several European countries including Germany and France have already prohibited its use in compost. Largely due to concerns over its role in the horrifyingly quick decline of honey bee populations. And as much as despise the wandering weevil, my friend the bustling bee is far more important.
So rather than opt for a pesticide, I’m afraid it’s back to basics. Destroy all compost and plants that have come into contact with the weevils. Place ‘trap’ plants, such as the ones mentioned above, between other vulnerable plants to entice greedy mouths away. Squish all adults you see. And whilst carrying out this labour intensive exercise, remember that bee queens and their colonies will be eternally grateful for one less hazard in their lives.
*UPDATE* Please do NOT use Levington Plant Protection Compost, as it contains a pesticide which could be a contributing factor to Colony Collapse Disorder in bee’s*
At this time of year I’m largely busy creating winter planting schemes and hanging baskets/window boxes for clients. Its not hard to create a bit of colour through the bleak winters (see my top ten plants for winter) but over the past couple of years a growing prevalence of vine weevil’s has caused complete destruction to multitudes of Cyclamen and I’m afraid it’s fallen to chemical control. Much as I hate to use chemicals within the garden unless it’s completely necessary, creeping around clients gardens at night in search of beetles might lead to an arrest or two. In addition, the lack of natural predators to this weevil plague means that, unless you’re willing to lose a few ‘sacrificial plants’, the chemical’s have to come out.
You have to admire these beasts in some way. There are no males, yes, that’s right, its a fully female world for the vine weevil. Reproduction is through producing eggs without the need to fertilise, and some 1600 eggs can be laid over a two month period by ONE female. Additionally, the adults feed at night, are quick witted and hard to spot. The larve spend their entire life underground, stripping plants completely bare of all roots until it’s too late to save most. And with very few naturally occuring predators, vine weevils are having a ball!
One sex only, Female’s rule the weevil world
Eradication can be difficult. The normal nocturnal pest collection regime is particularly hard as they are difficult to spot and drop to the ground at the slightest disturbance. ‘Sacrificial plants’ can be used, i.e. those that are more preferable to the little darlings, which entice them away from favourites. Polyanthus, Primula’s and Cyclamen are particularly tasty, but if, as I am, you’re actually trying to grow these species then you have to take further action. ALL compost the plant was in MUST be thrown away, with the roots being thoroughly washed and all grubs removed. Levington Plant Protection Compost can be used to kill grubs as they hatch and begin to feed. Alternatively use Provado, a chemical insecticide which will kill the grub army in their tracks.
Grubs have all but destroyed this Cyclamen’s root system
I’m afraid I’m now truly at war with these critters, I can’t even tolerate them in small doses. However, it does remind me of a funny story from a friend about pest control of aphids. Having a very bad infestation of the sap sucking insects, my friend’s husband got terribly excited when he ordered, from eBay, pest control. £20 spent and a few days later, the mysterious parcel turned up which was going to prove to be the turning of the tides in the aphid battle. Intrigued, my friend opened the packet, shook out the ‘biological control’ only to find that her husband had spent £20 on, wait, LADYBIRDS! I could have died laughing. For that price, I might start selling Harlequin’s and become a multi-millionaire!