Fear and suspicion of insects

Almost every week, one of our Grow Great Fruit members gets in touch saying something along the lines of “help, there’s a bug on my fruit tree!”

Back before we were certified organic we took a different approach to insects, treating them mostly with fear and suspicion, and we aimed to eradicate them, mainly with terrible toxic sprays.

We didn’t understand just how much damage we were doing, and it was an important part of our journey to learn to appreciate them.

A cicada on a fruit tree
A cicada on a fruit tree

There are so many hundreds of thousands of different insects that identifying a specific bug can be difficult (particularly as we’re fruit growers, not entomologists).

A macadamia flower with insects (look carefully...)
A macadamia flower with insects (look carefully…)

This is a close-up of a macadamia flower from our macadamia tree, and if you look closely there are 3 different insects hiding in there (admittedly, the one in the middle is very hard to see!).

We use one key factor as our guide to how we respond to any insects in the orchard – do we have evidence that they’re damaging either the fruit or the trees?

A caterpillar on an apricot
A caterpillar on an apricot

We reckon it’s so important to learn how to really LOOK at your fruit trees (rather than have a knee-jerk reaction to seeing bugs on them) that we’ve written a short course called “Learn to Diagnose Your Fruit Trees“.

If your monitoring shows that yes, the insects are doing damage, then the next step is to get to know as much about the insect as possible, particularly its life cycle, looking for a weak point where you can interfere in such a way as to stop the damage occurring, and this is one of the strategies we explain in the next course that’s relevant to the topic, Protect Fruit Trees from Pesky Pests.

We take this approach because it would be a huge challenge to try to learn about every insect in the garden, their interactions and whether they’re pests or predators.

Insects, birds, plants and even the microbes in the soil have complex relationships that we’ll never begin to understand in our lifetime, but what we’ve observed over many years is that as long as there is lots of diversity in the garden, populations tend to keep each other in check and become more balanced over time.  

Fabulous green bug
Fabulous green bug

Our experience on the farm has been that as long as we encourage LOTS of biodiversity, and take measures to protect our fruit without interfering with nature too much, we usually manage to live in harmony with all the critters in our orchard.

We prefer this to the “scorched earth” approach of killing everything that moves because, honestly, it’s very easy to do more harm than good once you start killing things in the garden.

Top 7 tips for aphid control

Have you seen any leaves like this on your tree? If you have—you’re not alone. It’s a classic sign that you might have aphids, and many of our Grow Great Fruit members are reporting high aphid numbers this year.

Leaves on a plum tree showing classic signs of aphid infestation
Leaves on a plum tree showing classic signs of aphid infestation

The curly leaves on these plum trees are the typical response to the sap-sucking aphids taking up residence on the inside of the leaves. It’s different to the Leaf curl disease that you sometimes see on peach and nectarine trees.

If you tease open one of the leaves you’ll usually find aphids of some sort on the inside.

If you get a really bad infestation, there’s no mistaking it because you’ll be able to see hundreds (or thousands) of aphids crawling around, as you can see on this peach tree.

Black aphid infestation on a peach tree
Black aphid infestation on a peach tree

These are black aphids, which are one of the more common types that infest fruit trees, and will usually be seen on cherry, plum, peach and nectarine trees.

Another common type on apple trees is called woolly aphid, for a very good reason:

Woolly aphid on an apple tree
Woolly aphid on an apple tree

There’s a third type of aphid that commonly affects fruit trees, and that’s green peach aphid, which — you guessed it — you’ll find on peach and nectarine trees.

Green peach aphid infestation on a nectarine tree
Green peach aphid infestation on a nectarine tree

Sometimes when you look inside a curly leaf to see if aphids are responsible, you might see something like this instead:

There’s only a couple of live aphids here, but those small black smudges are a really good sign, as they are the dried and shrivelled remains of aphids that have been killed by other insects – “beneficial” insects that do a wonderful job of keeping pest insects under control in healthy, biodiverse gardens.

Inside this leaf is a little community of insects that is a great sign of a healthy ecosystem. A spider, and an aphid-eating wasp are co-habiting and both eating their fill of aphids (or the spider might be eating the wasp – you can never be sure who’s eating who in the insect world!)

We’re often asked how to get rid of aphids, and unfortunately people aren’t usually very happy with the answer!

Biodiversity and patience really are the keys to getting the populations of these pesky pests back under control.

Whatever you do, DON’T SPRAY INSECTICIDE! It can feel like an easy solution, but you’ll inevitably kill predator insects and just make the problem worse. In most commercial orchards, aphid populations are high – and stay high, year after year, due to the use of insecticides that routinely kill the “good” insects that would naturally keep the aphids under control.

It’s expensive, it’s ineffective, and it’s bad for the health of the tree, the user, the eater of the fruit, and the whole ecosystem.

There are a number of home-made remedies that can help in the short term with aphid control, but our experience has shown over many years that similar to bought insecticides, if you rely solely on a solution in a bottle you quickly become dependent on needing to use the same solution every year, and in fact you can be making the problem build up over time.

So, here’s our top 7 tips for getting rid of aphids:

  1. Monitor your trees regularly, particularly checking inside any leaves that have curled up, so you actually know whether or not you have aphids.
  2. If you identify that you do have aphids, watch very carefully to see whether you also have any predator insects around that are eating them – spiders, ladybirds and wasps are all particularly voracious aphid-eaters.
  3. Check whether you have ants in the tree associated with the aphids. Ants like to ‘farm’ aphids by moving them from tree to tree and guarding them from predators.
  4. If you find ants in your trees, exclude them by any means necessary. Don’t bother trying to kill the ants as they bring excellent eco-services to your garden and are very hard to get rid of, but stop them getting to the aphids by putting sticky tape around the tree between the aphids and the ant nest.
  5. Focus on building the biodiversity of plant life under your fruit trees. Flowering plants, particularly white and yellow flowers are really good at attracting predator insects and providing them with habitat.
  6. Unhealthy trees will attract more aphids, so concentrate on improving the health of your tree by improving the soil it’s growing in.
  7. Use short term solutions (like organic sprays) only in extreme circumstances, and with extreme caution!

We recommend taking a more long term view by creating such a healthy garden that aphid populations are kept under control naturally.

Having said that, short-term solutions can have their place and are part of the “toolbox” of solutions in the Aphid Management Plan you’ll find in our Protect Fruit Trees from Pesky Pests short course.

Insects in fruit trees

In spring we reckon it’s a good idea to visit your fruit trees at least once a week, and have a really good look at the leaves, flowers, fruit and bark. It’s a good way to keep track of the health of your tree, and stay ahead of any disease issues that show up.

One of the more interesting looking insects you might see on your fruit tree
One of the more interesting looking insects you might see on your fruit tree

While you’re there, try to spot any critters living in and around the tree, like this great bug we found on an apricot tree.

It doesn’t matter if you can identify the bug or not (though that can sometimes be useful) – it’s safe to assume that it’s playing an important role in the ecosystem (like pollination, pest control, or acting as a food source for someone else), even if we don’t know what that is.

A bee working hard on a peach flower
A bee working hard on a peach flower

Many people mistakenly think pollination depends solely on bees, whereas in fact many insects play an important role (you can find out more about this important topic in Bees and Pollination).

Though it’s absolutely fascinating trying to figure out what sort of bugs you’ve got, identification is much less important than the fact that you have lots of biodiversity in your garden or on your farm. In short, the more different types of bugs you can count, the healthier your system is.

Amazing antennae...
Amazing antennae…

Why is biodiversity so important?

We often get questions from people who have noticed bugs or insects on their fruit or trees, and are wondering if they should get rid of them, and if so how?

That’s not our approach at all!

In a healthy, biodiverse system there should be literally thousands of different types of insects around, and they all play a part in an incredibly complex system that (if it’s not interfered with) will generally keep itself in balance.

Unless you’re an insect specialist, there’s little chance that you can identify them all or even understand whether they’re a “pest” or a “predator” – in fact, many are both. For example earwigs are a dratted nuisance in apricot and cherry trees, but a useful predator eating up millions of aphids in apple trees.

An earwig on a leaf  - pest or predator (or both)?
An earwig on a leaf – pest or predator (or both)?

So we take a different approach.

Rather than focusing on the insects themselves, we focus on protecting our fruit and our fruit trees from damage.

The methodology we use, both on the farm and in our ebook What’s Bugging My Fruit? is not to try getting rid of the bugs (which is usually impossible, frustrating and expensive), but to understand their life cycle and look for vulnerabilities where we can often use small, easy, physical interventions to stop them doing damage to our precious fruit. Over many years of growing fruit organically we’ve found this method much more effective.

So when you’re doing your weekly inspections of your fruit trees, look for bugs, but also look for damage on the fruit and the trees, because that’s what will guide you as to the appropriate prevention techniques.

A spined predatory shield bug
A spined predatory shield bug