Harvest Carrots & Avoid Sawfly InfestationsSeptember 17, 2012
Growing carrots? If so, carrot sawfly may have found your garden. While these flying insects can be great pollinators for your cilantro, their larvae can destroy emerging carrot, fennel, dill, parsley & cilantro crops, and they can do some serious damage to your carrot root crops as well. And, yep we’ve got’m in one bed – dammit!
This pest insect is a hard one to keep off your crops. The adults — tiny flying wasp insects that look more like black ants than true flies — love to feed on everything in the carrot family. And, they look a lot like many other tiny, black wasps. I’m no entomologist, so I won’t even begin to try to tell you exactly what they look like. But, I do know what their larvae’s damage looks like, and in one bed, my carrots had it, so we’ve pulled them and won’t be planting them or their cousins plants in that area again anytime soon. (Actually, we’re planning a big renovation for this area, so stay tuned for updates on that in the months ahead.)
Oh, and yes, we have practiced crop rotation here, but when even one tiny wasp makes its way to the crop, the larvae may thrive. And those wasps are small and sneaky little buggers!
If you haven’t pulled your carrot harvest yet and they’re about ready, go check how the crop is doing. If you don’t have any damage, consider pulling them before winter just to be sure you don’t accidentally over-winter the pest. If you do have an infestation, definitely pull the crop asap, and don’t plan to plant any nectar-rich,umbelliferae/apiaceae plants in that area for a few years. This will help you break the lifecycle of the pest — hopefully.
In urban areas, it may be tough to keep them out. Think about it: if a neighbor has overwintered the pest insect in (say) their parsely bed, when the adults emerge and smell your delicious carrots growing, they’ll be on those suckers like flies on, well, um, carrots in this case. So, when you do replant (in previously infested soil or not), try covering your freshly seeded crops with horticultural fleece, which may keep the flying adults out. They’re tiny little flying ladies, so it can be tough to keep them out even with fleece.
Oh, and yes, you can eat carrots with sawfly larvae damage. It may mean cutting out lots of damaged portions of the crop, but if you’re chopping up carrots for a stew, use whatever chunks you get there. They should still be sweet and flavorful. And who knows — maybe you’ll get a little larvae protein as well.