Estimated reading time: 5 minutes
Have you seen these slugs on your fruit tree leaves? Every year we hear from gardeners who worry that these creepy looking pests are attacking their fruit trees.
These are pear and cherry slugs, and as the name suggests, they eat the leaves on pear and cherry trees. On our farm, we’ve also seen slug damage on young plum trees at times, but it’s unusual.
The slugs look terrible, and so does the damage they cause, as you can see below.
Despite that, they are definitely not one of the worst pests you need to worry about. Certainly not as bad as fruit fly, for example, which is a key pest you need to learn how to manage.
Monitoring your trees early can definitely help
The first thing you’ll often notice is the damage to your fruit tree, rather than the slugs themselves.
You might notice that the leaves start to look lacy. The slugs eat the green part of the leaves between the veins, leaving the network of veins behind.
In a bad case, they may also eat the veins, which leads to brown holes and missing parts of leaves (as you can see above).
The first question to ask yourself when you see these slimy slugs (as with all pests and diseases on your fruit trees) is, how much damage are they really doing?
Fruit trees can actually tolerate quite a bit of damage without losing function or growth.
At Grow Great Fruit HQ our rule of thumb is that if a tree has lost more than 30% of its leaves to slug damage, that’s the trigger to treat them. We never use sprays unless we have to, but there is an organic spray available.
In all our years of growing, we’ve closely monitored every year, and never had to spray them.
Simple but effective slug control
One of the advantages of keeping a close eye on your trees is that you will often notice problems as soon as they occur. You can then take simple action, like squashing the slugs between a folded leaf.
In a normal season, this particular pest will go through at least two life cycles.
The more of them you squash as soon as you see them, the more you interfere with their natural life cycle and can prevent numbers from building up.
Usually what you will find is that if you are patient, a predator insect will come along and do your work for you.
A dry, parasitised slug on the leaf is the classic calling card, as you can see in the photo below.
Other control techniques
If the slugs get away from you and there are too many to squash by hand, you may have to try another technique.
Being moist-bodied, they’re very vulnerable to being covered by anything dry and dusty. There are a number of treatment options available to control a slug outbreak. For example, flour, wood ash or sulphur are three products in your potential toolbox that are relatively easy to access.
Whatever you use, it’s important to stand upwind and make sure you don’t inhale it. One of our Grow Great Fruit junior members is perfectly demonstrating the technique in the photo below.
So pear and cherry slug is an excellent example of learning how to watch your fruit trees.
Particularly keep an eye on the leaves. If you see some damage, dig deeper to learn what’s really going on, rather than assuming that if there’s a bug, there’s a problem!
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