Sawfly Larvae

I first noticed them yesterday evening on my currants and gooseberry plants and handpicked as many as I could before the sun went down. I did the same this evening, but they are completely infested. I picked over 300 off of just one plant! Interestingly, the gooseberry least affected by them had a baby snake in it - I'm guessing it been eating them as I only had to pick two or three larvae off that bush. I'm going to try mulching with rhubarb leaves as I read someone suggested on this site. I also read that they drop to the ground and pupate in the ground beneath the plant so one way to help prevent reinfestation is to cultivate the ground beneath the plants in the fall and winter in order to expose the pupae to cold and birds, but I read there can be up to three or four cycles of them every year. That's a lot of damage! Has anyone had any luck getting rid of these things?

Old thread, but wanted to see if you’ve learned anything more about these? I have a row of red currants that are infested, and I don’t want them to spread to others.

Unfortunately, I’m still battling them. I have, however, managed to eliminate them (for now) on the plants I sprayed religiously on a daily basis with a spray bottle containing a squirt of dish soap, three dropper fulls of neem oil, and the rest water. I also cleared away all of the vegetation growing around them, sprayed the ground with the same mixture, mulched them with about three inches of mulch, sprayed the mulch, and then sprayed everything daily until I saw no signs of sawfly larvae on the plants.

Since I have not yet had the time to do this with all of the plants and therefore some are still infested, I am still spraying the “clean” plants weekly, in case the sawfly from the infested plants decide to lay eggs on them.

Good luck with your plants - it’s been a tough battle, but one I’m finally winning!

Thanks for the response. We were able to pick off almost all of the larvae just as they were hatching and entering that explosive growth phase where they can quickly defoliate the whole row. There’ll still be some but we really knocked the bulk of the population down.

I think my situation is made worse by the fact that the currants are in a row, making it easy for the sawfly’s to take over the whole thing. All our other currants that spread out / distributed within a diverse forest garden don’t have this issue.

I also need to do some more serious pruning and mulching on the plants in this row, and I think that should help them a lot. The sawfly larvae start out on interior leaves/branches which I should prune out anyway. I’ve also noticed the birds are eating the larger larvae, but more so in the plants with more open interiors that allow the birds to hang out in, and don’t seem to go into the thickest unpruned areas of the plants. So I am going to try to prune them to be more inviting for small birds to hang out in and eat the larvae.

I read a great blog post by someone who basically said not to panic, they’re really not that bad, rarely killing the plants, mostly just reducing the yield, and actually providing food for birds and wildlife, and I like that perspective. I just want to learn more about them and try to design more balanced systems. It’s like the sawflys are showing me that a monoculture of red currants isn’t in balance with the ecosystem. I’ve been propagating a lot more red currants and spreading them around so I’m interested to see if they’ll be affected differently by the sawfly in a more diverse polyculture setting.