Hartley Magazine

All the latest news, hints, tips and advice from our experts

Wasp Worries

With summer in mid flow there’s one garden pest that is taking the starring role, the wonderful wasp.

While most people consider the wasp to be a huge pest, and it can be, in gardening terms the wasp is actually a very beneficial insect. It is a predator of many garden pests and will devour a range of pest problems including aphids and caterpillars, which also abound in midsummer.

By midsummer the wasp is mid lifecycle and the numbers of workers in its nest are multiplying. An average healthy wasp nest could have in the region of 40 thousand wasps in it. The majority of them are worker wasps collecting food for the developing larvae.  That means thousands of worker wasps collecting aphids, bugs and caterpillars for up to 2-miles around each nest. That’s an amazing natural weapon in the war on garden pests.

Now I’m not suggesting that wasps aren’t a bit of a nuisance, especially in the summer when garden owners try and make the most of a sunny weekend for a barbecue, picnic or afternoon tea. But if you spend a little time understanding the lifecycle of the wasp then you may be a little more forgiving. Wasps are part of the food chain and a valuable pollinator species too.

Royal residence

The Queen wasp hibernates over winter and emerges in spring as the weather warms. I often have two or three Queen wasps appearing in my greenhouse in spring. It’s a perfect place for them to hibernate, as it’s dry and much warmer in there. It is a bit disconcerting when you are sowing seeds and potting up to find a huge wasp flying straight at you at great speed. But if you don’t swat at them and actually watch what they do, invariably they will find some soft sappy plant that has a greenfly coating and start to devour every last one of them. It’s great greenhouse pest control and since they don’t stick around in one place and I won’t be spraying them either, a winter’s shelter is a good exchange for some early spring pest control. Yes I do worry that they will make a proper nest in there, but so far they have all been released to the garden to take their chances and have made their nest elsewhere.

Sugar Snacks

The reason wasps are so aggressive in summer is because they are addicted to sugar. I can sort of understand that. I get a bit grumpy if my blood sugar is low and someone’s eaten everything sweet in the cupboard. For wasps it’s a very interesting process. The worker wasps collect food for the developing larvae and when they feed them they receive a sort of sweet reward in return. That goes on until the Queen stops laying and the larvae are all mature. Then when there are no more grubs to feed, the workers go in search of sweetness elsewhere, which is why you will find them in your cans of fizzy drinks, jam pots and all over the garden fruit. They are seeking that sweet reward that is now lacking in their lives. And when they find it, they return to the nest, in a similar way to bees and communicate the location of the sweet treat to their buddies. This usually starts in July and August, which of course coincides with school holidays and sometimes, nice sunny weather.

Live and let live

July2015If you have a wasp nest in the garden unless you stand on it or threaten it in some way you are pretty unlikely to be stung around it. Unless your wasp nest is somewhere that it will pose a threat to children or vulnerable adults, then the best thing to do is to leave it alone, keep clear of it and allow the nest to go through its lifecycle. Yes it will grow and produce more wasps and later in the summer it will make Queen wasps for next year, but most of these will die in the cold and only a tiny percentage will go on to build a nest next year, usually as few as 3 in every 1 500.

 If you consider that there are probably around 1000 wasp nests in a square mile and that each wasp can fly up to 2 miles, then even if you annihilate your nest, there will be plenty more wasps that will take their place and potentially cause a nuisance. Balance that out with the fact that the workers from an average wasp nest will eat 4 to 5 tonnes of insect pests in their lifetime and thus vastly reduce the need for pesticides and you can start to see that they do more good than harm.

Instead of calling the pest controller, or the council, consider whether you can live and let live instead. It will save you on average around £70 and be better for the environment too.

It is better to act calmly around wasps, protect food and drinks from their attention by covering them up and by keeping rubbish covered and safe. Most wasp sting incidents are associated with and around food and drinks.

Wasp traps have variable effect. The worst thing you can do is set up a wasp trap that the wasps can escape from because all that does is allow the workers to return to the nest with the great news that they have found a fantastic source of sugary sweet food (wasp bait) and then more arrive to cause havoc.

Over the years I’ve trialed a few products and the one that works the best for me is the WaspBane. http://www.waspbane.com

It’s a bit pricey but it costs less than the pest controller and it really does what it is supposed to do, ie. It effectively traps the wasps and prevents them returning to base. Put it in place after mid summer when the Queen wasps are no longer foraging. Place it to intercept wasps before they find the food source and downwind of any areas you wish to protect. It needs to be in full sun for the bait to warm and release its aroma and out of sight and reach of children. Full information, tips and advice can be found on the website (above).

Unlike honeybee colonies, a wasp nest is very like a bumblebee nest in its lifecycle in that it will only be active from spring until late autumn. Wasps are very territorial and rarely repopulate an area where there has been a nest before. So if you find an old nest in the attic, shed or garage, leave it there as a wasp deterrent. You can even buy fake wasp nests to hang around the garden to deter queen wasps from setting up home.

So next time you find a wasp nest or have one trying to share your lunch, remember that these stripy insects have a role to play in the garden and do more good than harm.