Allotment, Blog

Natural Pest Control

Just a few weeks after planting our apple trees we have an aphid infestation!

I first discovered the little beasties when I noticed one of the trees was looking decidedly droopy. The leaves were yellowing and curling up. At first I thought it might just need watering, but when that failed to perk it up I inspected the leaves a little more closely. There, on the underside of the leaves, were groups of tiny black aphids clustered together.

Aphids are small sap-sucking insects and are known commonly as greenfly or blackfly (depending on their colour). They suck the sap from foliage, stems or flowers but feed from the roots of the plant. They can cause stunted growth in plants with curled or distorted leaves and can weaken the plant.

To start with I just picked off the affected leaves and popped them in the bin. Unfortunately this hasn’t worked, and if I pick off many more leaves I’m worried my tree will be bald.

We want to garden as naturally as possible so we’re not running out to buy an insecticidal solution to this problem. Thankfully aphids have natural predators, including ladybirds, hoverfly larvae, lacewing larvae and parasitic wasps.

I have seen a lone ladybird on the tree but we have ants ‘milking’ the aphids for sap. The ants will farm the aphids and protect them from ladybirds.

Our first step is to deter the ants. We are going to put a barrier of Vaseline around the tree trunk so that it is harder for the ants to get up and down the tree. Then, we are going to sprinkle down some cinnamon, which we’ve read ants hate. Once the ant issue is under control the aphids will have no protection from predators. So, our next step is…

Find a predator for the aphids! This is the bit I’m actually a little bit excited about. We have ordered some ladybird larvae online. There are ladybird babies arriving by post!

Ladybird larvae will eat their weight in aphids each day. They are fantastic natural pest control. The larvae come with a release bag, which you hang in the tree. They then make their way out and gobble up all the aphids. As they can’t fly away yet they will remain on the tree until they undergo their metamorphosis into ladybirds.

It is important to ensure that you buy British Native Ladybirds (Adalia bipunctata), the two spot ladybird, not the invasive Harlequin Ladybird species. You can find them easily online with a bit of Googling but I like to buy from Green Gardener.

I’m hopeful that our planned solution to the aphid problem is going to work. We’re off to the allotment in a bit to get the tree prepared for our babies’ arrival. Then we really ought to look into putting up an insect house so that they have somewhere cosy to go over winter.