Ambrosia Beetles- not so sweet
2022 started out similarly to 2021- we had a long false spring in late winter, followed by a freeze. It wasn’t a late freeze, but the false spring was long enough that our figs had broken dormancy and leafed out. They were damaged, but not frozen back to the ground like in 2021. So, we were hopeful.
Then, a week later, we saw something we’d never seen before- it looked like toothpicks sticking out of the trunks of some of our one year old trees. It was Good Friday, before Easter, and the Walton County extension had already closed for the day, but Google told us that it was a pest called ambrosia beetles. The extension office helped tremendously on Monday with figuring out a plan.
The first thing that needed to be done was to prune/cut down and burn any attacked trees. There are strong pesticides that can be used to kill the beetles and prevent further damage. We aren’t going to go that route. We have so far cut down 27 of our fig trees, one jujube, and one pawpaw. The figs and jujube will most likely grow back, but we’ve lost a year’s growth. The pawpaw is gone.
The prevention for this bug is spraying with permethrin. We grow organically, and we won’t spray permethrin. If you want to do that, please check with the extension for the details of how to do it.
As far as how to treat this organically, we’re trying to figure that out. Knowing your enemy is the first step in organic growing. This little beetle is tiny. These little jerks are drawn to the ethanol that is released from stressed trees. They burrow into the trunks of stressed trees-such as our figs that had begun leafing out and been damaged by a late freeze. The “toothpick” that you see is the chewed up wood it spits out behind it. It brings fungus with it, that it farms inside the tree. The fungus will kill the tree. The beetle lays in its little den inside the tree, called a gallery, and raises the next generation. The only treatment is to prune and burn. The beetle will go for figs, pawpaws, persimmons, apples, peaches, plums, and many other fruits and ornamentals.
We have set out traps to try and keep them away from our pawpaws and persimmons, which would not regrow if cut down. The traps are simple- they are drawn to ethanol, which is released by stressed trees. Hand sanitizer containing ethyl alcohol draws them, and they get stuck in it. So, a 2 liter bottle with a hole cut out, and a few squirts of hand sanitizer in the bottom, hung from a tree, is effective. They say it doesn’t kill the entire population, but it is satisfying to see the ones it does kill.
Keeping your trees fed and not over and under watering are big tickets to keeping them from stress. We do soil samples every year, and because we run our birds through our orchards post harvest, our results are good. Our soil is happy and fertile. In addition, we are feeding our figs through fertigation- fertilizing through the drip irrigation. We check our moisture levels with moisture sensors at 18 inches and 3 feet down, as well as manually checking the soil, and water accordingly. We mulch heavily to lower our water needs. One mistake we see people make with mulch is to water the mulch. Mulch can soak up a lot of water that then never gets to the tree. Our drip lines are under the mulch, so we are watering the roots of our trees when they need it.
Even if you have only one tree, you can still do a soil sample. The extension will give you a report including detailed care instructions for your tree or bush. Seriously, y’all, this is the best thing you can do if you plant anything. Don’t overwater. Check the soil for moisture- just dig down an inch or so with your finger and see if there is moisture there or not. If you have mulch, make sure the water is getting to your tree and not just the mulch. If you don’t have mulch, water in the early morning or evening when the sun won’t burn it off as quickly as you water.
The main thing is prevention. Keeping trees healthy and strong. Nature hasn’t cooperated with that this year, but we will figure out what to do between now and next year.
We don’t know yet what this will mean for our fig crop this year. We’ll have to wait and see what survives, what grows back, and how much growth we can get. We’ll keep you posted!
I’m so sorry you’ve been attacked by these pests. Here’s to hoping your solution works. Please let us know if you have any success. I’m really looking forward to figs!
Thank you Dianne, we really appreciate it! We’re hoping our figs can grow back and recover. We’ll be keeping everyone updated via our newsletter.