What the heck is in my tree?
Have you noticed any webs that seem to be swallowing leaves and branches in trees lately? Well, I have, and so have many of my friends. What we are all seeing are fall web worms.
It’s kind of creepy, but it doesn’t need to be scary.
If you’ve taken a closer look at the webs, you have probably noticed the creatures responsible for the construction. It might have made your skin crawl a bit, but don’t worry, the hairy worm-like creatures are just moth larva native to North America. They are completely harmless to people. The webs are a way for them to protect themselves from predators as they grow—which is pretty cool in my nature-loving opinion.
…but what about the trees?
There is no need to worry too much about your trees either. The main problem is mostly aesthetic. The large webs might not look good to your eye, but these web makers rarely do permanent damage. They will defoliate the branches they are on, and in some cases, this means the entire tree. You might have a need to be concerned if this happens to the same tree year, since this will certainly stress the tree over time.
What can be done?
If you have a small infestation, prune the webs off of the tree if you can reach them. What you do with the wormy, webbed branches is up to you. Some options are to burn, soak them in soapy water, or tear open the webs and let the birds eat the larva. Keeping small infestation under control will also aid in limiting the population from getting large enough to defoliate whole trees.
You can use a variety of pesticides, both organic and non-organic, to kill bigger larva infestations, but I wouldn’t recommend them for this situation. Keep in mind that webs can be hard to penetrate, and it can be difficult to spray a tall tree safely and uniformly.
If you are unable to remove the webs by pruning, the best solution would be to wait the season out and spray dormant oil on them in late winter. The larva will eat during the fall, pupate, and overwinter on the trees to later emerge in the spring as adults. The dormant oil will smother them before they emerge, and this will go a long way to eliminating the problem for next year. If the tree has been infested for years or had a large infestation during a single year, it might take a few years to get the web worms completely under control.
Does this worm larva bother you and your trees? Do you think they are creepy or kind of cool?