Sawflies have pretty much defoliated my wonderful little river birch. Just look at the tree!! I planted this little guy two years ago as a six foot tall sapling, it is now about 12 feet tall and very full-or should be. I kept seeing the leaves disappear, but try as I might I could not find the culprits. That is until I got really desperate just knowing my little birch would be no more if I did not take action.
On one sultry morning I decided to look real hard for the bad, bad pest. I even picked a leaf that still had some leaf on it (this is where the boogers were) and brought it closer to my eyes-poor eyesight you see. Obviously I must have poor eyesight since it took me so long to find the million caterpillar army! That is my story and I'm sticking to it! Can you see the little squad of the pests all lined up munching away on this leaf?
Look, here is the rest of the platoon going to town on a leaf still on the tree! It is characteristic of sawfly larvae to arch up into an S-shape when disturbed. They were seriously disturbed on this fateful day. I am not abashed in saying so-I won the war! Disclaimer: Yes! All of these sawfly larvae perished!
This handy bottle of a botanical insecticide helped me out. I was ever so happy I had it on hand. Normally I do not use insecticides with the exception of Sevin dust on my zucchini and broccoli plants. Sevin dust would've worked well but could you just see me up on my ladder sprinkling the white dust all over the million caterpillar army? Nope, me neither. I tried this spray and it worked wonders! Its main ingredient is a pyrethrin; which is a natural substance, though still dangerous if not used in the manner intended. I learned all about this insecticide in my pesticide class at Nashville State Community College (NSCC) and really do appreciate the information. I only had it on hand for pesky houseplant bugs but it worked well on these sawfly larva as well.
The spray was easy to use (make sure to use on a calm day) and took care of the million caterpillar army within about 15 minutes. Yup, they were not killed outright, but die they did.
The poor birch will not re-grow its lost leaves, but will continue to grow new ones at the tip of the branches and it will recover. I have resolved to use Bayer Advanced Tree and Shrub Care systemic insecticide on this tree in the future. That insecticide is reputed to last more than one year. I try to garden totally organically, but sometimes I just have to take action to save prized plants in the garden while weighing the risks and benefits of my actions. Let me tell all you gardeners, Japanese beetles have NOTHING on these sawfly larva and they are bad!
On a good note, the following insect is a welcomed visitor to my garden. The 'parsley' caterpillars have finally arrived! Thank goodness they are not pests and I have no problem with them eating my parsley and Bishops weed (which is where I found this fella).in the garden....hoping my birch tree recovers soon.