Check your evergreen for bagworms!

We just found out that our evergreen tree was infested with bagworms. At first glance, they appeared to be little pine cones so they looked like a natural part of the tree, but they are not! When we looked closely we could see the little worms peeking out from the top of the pinecone-like bag.

Left unchecked these critters will kill your tree. Do yourself a favor and check your trees for them. I see many trees in our neighborhood that have already turned brown and can see the bagworm infestation on them.

Do a google search on "bagworm" and you can find lots of good information. Here's what I've learned in the past few days:

- This time of year, the bags are probably large enough that pesticides will not help. The 'bag' is just tree material that the worms have bitten off the tree and woven into a silk to protect themselves -- a pesticide will not get inside the bag.

- To get rid of them, you need to pull the bags off of the tree. Drop them in a bucket of soapy water to kill them. If you just drop them on the ground, they will find their way back to the tree!

- Although the worms may appear to be 'emerging' from these bags, they never come all of the way out. They will stick their head out just far enough to bite off a little bit more of the tree and to push themselves further down the branch they are attached to. This is how they grow the 'bag' and also how they kill your tree.

- Check back every few days to get the ones you may have missed. The bags will get bigger over time so if any are small enough to evade detection the first time around you will see them later.

- Even if your tree looks unaffected now, check periodically for possible infestations. I am pretty sure we saw one (ONE!) of these on our tree last year, but thought it was some sort of natural part of the tree. We left it alone and this year we found over 500 of them spread over the entire tree. The one we left last year had become HUGE.

500 may seem like a huge number but it only took me about 2-3 hours to pull them all off. I think (hope) I got them in time to prevent permanent damage to our tree.

 

Do you know if they're particular to specific types of evergreen trees?

 

We had the same thing happen to our evergreen in front of our house. We didn't know what the heck they were until a friend of ours told us. We ended up losing the tree and dug it up this past spring. Those bagworms are nasty!

 

The trees I've seen them on locally are the narrow, 6-8 foot tall trees that many of the townhomes have in southern walk. I don't really know if they're particular to that type of tree or not.

 

We had these on a pine tree in our yard last year and they almost killed the tree. When I went to get something to spray on them I was told that it was too late in the season...I needed to pick them off. Not fun, but it did save the tree. Guess I need to check to see if they are back again.

 

For next year is there anything that can be done other than pesticides to keep these guys undercontrol in the future?

 

I've seen many recommendations for using Bacillus thuringiensis (Bt) in the early spring, which is early enough in the bagworms' lifecycle to have an effect. Bt is a type of bacteria, not a chemical pesticide, so it's considered organic.

I get the feeling that regularly checking your tree for these bags and removing them may be equally effective. One bagworm won't do much damage by itself, but if you leave it be, each female lays 500-1000 eggs inside the protective bag, enough to spread throughout the tree the following year. We saw one on our tree last year but didn't identify it as a problem (it looks like a natural part of the tree). It would have saved me a lot of work if I had just removed it last year.

 

In our case - I was actually glad, because we had been wanting to get rid of that evergreen anyway - the builder had put it right in front of our porch and it was so big, and after pruning it several times, we decided it was more of a nuisance and actually blocked our view from our porch as well. It was 12 years old, looks so much better without it now.