Gooseberry Sawfly is the number one problem for anyone growing Gooseberries here in Donegal.
A full plant can be severely defoliated in a few weeks if these hungry little chaps are left unchecked.
The caterpillar like larvae from the Female Sawfly are active from early May here in Donegal, after hatching low down on the plant the larvae then munch their way happy, growing rapidly in size and with it their appetite growing hugely too!
The first step is to regularly inspect your Gooseberry plants for the early signs of larvae feeding, at this stage the small larvae can be squished or picked off before much damage has been done – the spanner in the works here is the sheer volume of thorns on the Gooseberry plants… which makes thorough inspection of the foliage difficult.
If you miss them early you’ll soon notice the damage they cause, but as they get bigger the removal will be a bit easier. It is important that you do remove or control these larvae as in one season you can have multiple generations on the same plant, so regular inspection on a weekly basis is advised.
If picking and squishing isn’t your thing then look out for some Pyrethrum contact Insecticide, use this natural (but potent) insecticide to kill the larvae on contact.
Prevention of Sawfly occurrence is a multi-pronged approach, firstly you have to look at pruning and opening up the crown of your plants to improve air flow, reducing the cover available for newly emerging larvae. Next you can use a winter wash on your plants to remove any overwintering eggs.
Lastly to prevent the adult female sawfly from laying eggs on your plants you can use a Garlic based spray as a deterrent.
Although not fatal in itself sever attack by Sawfly will weaken the Gooseberry and reduce fruit size and overall yield. However if attack is regularly suffered over a number of seasons the plant may be severely weakened.
Fresh gooseberries are such a delightful crop that it’s a shame to give up on your plants just because you’ve been struck with Sawfly damage in the past!