Estimated reading time: 5 minutes
It’s common to see tiny little Rutherglen bugs on your fruit tree in summer. They sometimes show up when the fruit is starting to ripen. Have you noticed any on your fruit?
We first learned about these little bugs the hard way. One very wet year we (and everyone else trying to grow fruit on the east coast of Australia) had a plague of them. Thankfully we’ve seen very few since then.
However, they continue to show up in different places, so it’s a good time to show you what to look for, and what to do.
Identifying bugs on your trees and fruit
The bugs in these photos are called Rutherglen bugs. They are tiny, and a nuisance, and if there are enough of them they can wreck your fruit.
Rutherglen bugs are in a category of insects called sapsuckers. They suck the juice out of your fruit and large numbers can cause the fruit to shrivel up.
The year that we had a plague a small proportion of our peaches had so much juice sucked out that they weren’t usable. Luckily most were still fine and we were able to sell them at the market as usual.
The bugs can leave a slightly sticky residue on the fruit as well, but this washes off.
Why do some bugs come and go?
Interestingly, we’ve barely seen them since. This is often the way with ‘plagues’—they’re usually the result of an imbalance in the ecosystem that has temporarily favoured one insect over another. They usually quickly get back into balance and numbers go back to normal (i.e., hardly any).
This is in direct contrast to pests that tend to stick around year after year. Fruit flies and earwigs are in this category, though their population density can still fluctuate widely depending on the season.
So, why do plagues disappear?
Mainly because these insects have a lot of predators. Nature tends to get these population explosions under control all by herself, as long as you have decent biodiversity in your garden, and IF you don’t mess things up by using pesticides.
Protecting fruit from bugs
When you are experiencing an outbreak it would be nice to protect your fruit, right? Most gardeners don’t want to just abandon the crop to the pest outbreak and hope that things correct themselves by next year.
You want to take action, right?
Before we give you some practical tips for what to do, we’d like to suggest what NOT to do – and that’s to reach for a bottle of insecticide.
Using off-the-shelf chemicals to kill things in your garden is a potential recipe for disaster. At best, they’re often ineffective (and you’re giving yourself and your family an extra dose of chemicals in your diet).
At worst you may accidentally kill good insects and maybe even make the original problem worse. You’ll also be making your garden a much less welcoming place. It’s really easy to do more damage than you can prevent.
Here are our top 4 suggestions:
- Hose the tree when it has a large swarm of bugs on it. This should discourage the bugs that are on the tree at the time. If there are lots around in the garden the tree will probably be re-infested and you may need to repeat.
- If you have chickens or other poultry, confine them to the area around your fruit trees if possible. They’ll love to eat the bugs. As above, if there are lots of bugs around, the tree may be re-infested when you remove the chooks.
- Protect the tree with a very fine net. Use the same sort you would use to prevent fruit fly from getting to the fruit. As you can see in the photo above, they easily get through regular-sized bird netting.
- As a last resort, you can try a home-made organic spray. Be very careful if you do this. Even though home-made sprays are safer than bought chemicals, it can still be easy to do more harm than good by killing the predator insects that will be eating the Rutherglen bugs. You may accidentally make the problem last longer.
Long-term bug management strategies for your fruit trees
The key message is don’t worry too much about them. They’re quite hard to control in the short term, but they often won’t do too much damage, and next season the plague probably won’t be back.
Concentrate instead on the long-term strategies for managing these bugs (and all the other pests as well):
(1) continuous soil improvement,
(2) continuous biodiversity improvement,
(3) continue to educate yourself about individual pests that might cause problems for your fruit, including their lifecycle, how to identify them, tips for prevention, and treatment strategies.
The best place to start? Read our other blogs about pest control.
The story of how Queensland Fruit Flies meet, mate, and reproduce. Everything you need to know to learn how to beat these pests.
Finding insects in your fruit trees scares a lot of people, but in fact, a wide variety of insects is a good sign of biodiversity.
The classic “worm in the apple” is actually the larvae of the Codling moth, a very annoying pest that needs a planned effort to prevent.