-
Those are tent caterpillars, the particular species depends on your location. They defoliate the tree. Best way to get rid of them is to smoosh with your gloved hands. If you can’t reach and haven’t pruned that branch yet, it might be worth pruning to get to them. There may be some sprays, though I do not know how helpful those are.
I think, in general, any caterpillar on a fruit tree is a pest. Let me know if I am forgetting about a beneficial species.
You reminded me I saw a web of them on one of my apples last week… but forgot to deal with it. Will now, thanks for the reminder!
If they’re on a branch that’s not too big, I tend to prune it off and dunk the whole thing in a bucket of water. The caterpillars soon perish. But sometimes that’s not possible, so I just do the best I can pulling the whole nest away from the tree before drowning them.
I don’t think they’re a huge threat, but if you let it go, their population will eventually explode.
With regard to Josh’s thinking that, “in general, any caterpillar on a fruit tree is a pest” it might be useful to think of the situation in a more nuanced way. I tend to agree with the statement, especially with regard to the potential defoliation of younger trees, but there are various benefits from a holistic management standpoint to having organisms that are a pest at some stage in their life cycle present. For example, they are a food source for birds or they may later become a pollinator.
That said, there are established tent caterpillar populations in the native vegetation surrounding my farm and I, like Josh and Craig, take the preventative precaution of removing caterpillar webs from my fruit trees.
That’s a helpful addition to the conversation. Should’ve mentioned…
I don’t foresee ever eradicating them, and I don’t feel compelled to do so. We live among a stand of hardwoods and pines that host a healthy population of these caterpillars. So there’s plenty for whatever feeds on them. I just think it’s good hygiene to keep them from setting up so numerously in the orchard as well.
Having said, maybe instead of drowning the web, I’ll see if our chickens like them!
A few bits of additional info that may be helpful to others: Tent caterpillars usually occur in the spring while related species of fall webworms occur in the fall. Both are sporadic pests; fairly easily controlled with physical measures (i.e. sticky bands, removal) and indigenous to N. America. Gypsy moth (now renamed Spongy moth) is a non-web making, non-native pest that may infest some fruit trees species and I have had what may have been caterpillars of that type a few times in my orchard. I was able to control them by removing and destroying them from younger, establishing trees and following up a few times in my small orchard.
An interesting side note is, with the ongoing explosion of emerging cicadas in the midwest and southeast regions, significant ripple effects are expected within forest ecosystems. They include an increase in caterpillar populations due to birds and other bug eaters gorging themselves on cicadas. Cicadas are also one of those species that cause slits on your fruit tree branches where they lay their eggs though this is usually something that doesn’t hurt your trees too much.
Pommes de Terre Acres
Western Intermountain RegionSteve, that is a wild side note about the increase in caterpillar populations. We have noticed a huge number of full grown caterpillars wondering around places they are not usually found. Looking online, it seems this species often has “outbreak” years, and perhaps our Cicada emergence a couple years ago helped this generation out, though indirectly. We have a bit of a forest on our property, so there are lots of possible habitats for them nearby other than our orchard. Anyways, as I look into these caterpillars more than I have usually, I notice the egg casings that I saw back in pruning season, and that I meant to look up, seem to have been caterpillar egg casings. Oops!
Not sure if Dipel BT works on this stage of the caterpillar larvae, but since they are everywhere (and not in a tidy webbed package anymore), I am going to give it a go, especially since we have other leaf eating pests to target.
You must be logged in to reply to this topic.