Shield Bugs and Your Garden: Good or Bad?

Shield bugs (also called stink bugs, quite affectionately) are often seen as a nuisance in our homes. If you’ve ever squished one while chasing it around your living room, you know exactly what we’re talking about.

But if you spot a stinker or two in your garden, don’t rush to get rid of it immediately! There are a few different types of shield bugs in the UK, and while some of them can easily ruin your produce, others can actually be helpful!

So, stick with us if you’d like to learn more about how shield bugs can benefit your garden, and how to defeat the ones that don’t.

If you are:

• A hobby gardener;
• The owner of a sizeable collection of houseplants;
• Starting to notice multiple shield bugs hanging around your plants and produce;

Then this post is for you!

What types of shield bugs are there?

The most common types of shield bugs you are likely to encounter in the UK are the brown marmorated stink bug and the green shield bug. They are roughly 2cm long and wide and are often mistaken for beetles. But they are not! They are actually members of the “True Bugs” family, characterised by piercing-sucking mouthparts and wings that form a triangular shape on their backs.

Both types of shield bugs can often be spotted in the garden during the summer months when they are most active.

Although both brown marmorated stink bugs and green shield bugs are overall harmless to humans, they can destroy flowers and fruit trees. So, if you are a gardener, you would not want to see too many of them. And if you are a winemaker or enthusiast, you probably despise them from the bottom of your heart, because they can easily disrupt the balanced flavours of wine.

What do shield bugs eat?

Shield bugs enjoy fruits and vegetables. Some of their favourite meals are apples, peaches, cherries, and tomatoes. Shield bugs will also munch on corn, beans, peppers, and green salads. Hence, they can be a threat to a garden.

An interesting fact is that when a stink bug takes a bite from a fruit, it ruins its taste. If you have ever tried a cherry that had an oily, awful taste, it might have been bitten by a shield bug.

You should not jump to drastic measures when you spot a shield bug in your garden, though. Because there is a beneficial type that, as a matter of fact, could be used as natural pest control.

Good and bad shield bugs for a gardener

When it comes to insects infesting your house, there are hardly any bugs that you might find beneficial. However, if you are a gardener, it is important to know that there is a type of shield bugs that might help you in the fight against garden pests.

The predatory shield bugs (Picromerus bidens) hunt down and eliminate all sorts of larvae that usually munch on your plants. You can easily tell them apart from other shield bugs by the spikes on the front of the pronotum (their shoulders). These shoulder plates, the thicker mouthparts, and the yellow band on their antennae are what you can use to spot the difference between them and brown stink bugs.

While in their nymph stages, you can rely mostly on the bands on their antennae. Stink bugs will have white bands and predatory shield bugs will have yellow ones. However, it can be quite hard to notice the difference.

How to check for shield bug eggs in your garden

Shield bugs usually have 2-3 generations per year during the summer months. The females will lay their eggs underneath host plants. So, the way to check for them is to follow the stems of plants and look for a cluster of 20-30 small, yellowish eggs. After roughly a week, those eggs will hatch and the nymphs will pop out and start feeding.

How to treat shield bugs in your garden

If you’re lucky enough to have beneficial stink bugs in your veggie plot, you wouldn’t want to get rid of them. Alas, sometimes their less friendly cousins take over instead.

If you want to remove shield bugs from your garden, the method will depend mostly on their stage of development and the severity of the infestation. If you are seeing a couple of adults here and there, you can easily handpick them and squish or release them somewhere away from your garden.

***

Have you dealt with shieldbugs in your garden? What kind of solutions did you use? Are you sure it wasn’t predatory shield bugs? Please, share your stories in the comment section!

Image source: Shutterstock / J.J. Gouin