One could complain that this blog allots way too much space to two topics: tidying up and complaints about squirrels. At the risk of repetition, let’s discuss the squirrel issue this morning beginning with a year end review of our fruit harvest totals:

Fuji apples: 0
Winter banana apples: 0
Fuyu persimmons: 0
Hachiya persimmons: 0
Peaches: 0
Pomegranates: 6
Figs: 20?
Avocados: 20? but with a few bite marks

So not a total loss in the pom department but a long ways from my days of thinking that the hard skin of pomegranates are squirrel proof.

This is the point in my squirrel complaint blog post where I lazily link to UC Davis’ squirrel management notions. It’s also the paragraph in which I claim to have discovered a miracle squirrel cure in the form of a lame old man joke. Now you’ve got a bad case of earworm. Go ahead and suggest dogs and rifles in the comments and you’ll see us soon on a PETA billboard.

After watching a squirrel chew up every single peach on our little tree, despite deploying yards of bird netting, I found myself pondering extreme and deadly measures. Then I found myself fantasizing about what I would do if I were Elon Musk. First, I’d give up on the mars idea. Mars is, after all, a lifeless, barren speck of dust lacking life’s essentials such as breathable air, plants, cats and Parmesan cheese. Why bother? How about, instead, turning that technical know-how towards the most important issue of our time: squirrel deterrence.

As it turns out I’m not alone. At a Python programming conference, back in 2012, software engineer Kurt Grandis presented a research project he entitled, “Militarizing Your Backyard with Python: Computer Vision and the Squirrel Hordes.” Grandis’ motivation was a squirrel attack on his peach tree and, worse, his kid’s pumpkin patch. The full lecture details Grandis’ attempt to create a program that would differentiate between squirrels and birds and then deliver a carefully aimed blast of water at just the squirrels. It’s worth viewing in its entirety just to hear how Grandis resolves the image recognition question, “What is squirrelness?” If you’re impatient you can fast forward to the 16 minute mark for the video. Spoiler alert: it works, at first, and then the squirrels quickly learn to ignore the blasts of water.

It leaves me wondering if a scary clown strategy might work better such as it did with this bear:

Kidding aside, two Southern California biologists are using high powered lasers to dissuade ravens from attacking endangered desert tortoises. The biologists are also speculating about the possibility of “gamifying” this task by opening it up to anyone who wants to take a potshot via the internet. Which leads to my question of the day. Would you readers be interested in a gamified laser squirrel shoot in the Root Simple backyard? Time to learn Python!

Save

Save

Multiple entry holes on avocado trunk. Photo credit: Eskalen Lab, UC Riverside.

Of all the plants in our yard the one I care most about is our avocado tree. I’d be despondent if anything happened to it. Which is why I panicked when I first heard about the Polyphagous Shot Hole Borer (PSHB), a beetle that spreads a fungus Fusarium euwallacea. First noticed in 2003 here in Southern California, the PSHB seems to damage some trees more than others.

Concerned about losing my avocado tree I wrote Akif Eskalen, a plant pathologist at the University of California, Riverside. Dr/ Eskalen’s lab has done a lot of work on the PSHB and what to do about it. I asked him specifically about avocados and here’s what he had to say in an email,

My lab has been conducting a continuous survey on PSHB on infested and non-infested avocados in California since 2012. Based on the preliminary results from our survey the beetle PSHB seems to be attacking and causing damages on primary and secondary branches of avocado only. We have also seen attacks on the trunk of the trees but somehow the beetle is not successful establishing galleries there which could cause of quick death of the tree. I believe with a proper orchard sanitation you can reduce the damage of the beetle and also keep the beetle population down in the orchard . . . we are still continuing experiments with different insecticide and fungicides on avocado against this beetle and their fungi. An insecticide (Hero) has already registered under Section 18 that could be used by growers in CA.

He provided a link to a short publication his lab put out on orchard sanitation best practices as well as a link to information for avocado growers on the use of Hero. Hero is a pyrethroid-based pesticide.

For my own backyard tree I’m going to:

• Make sure pruning tools are disinfected before use. This is one of the main reasons we use a qualified arborist.
• Avoid moving firewood around. I’m going to have to think carefully about the wood I import for my pizza oven.
• Use mulch that has been chipped to less than 1 inch.

I’d sure hate to lose a tree that provides six months worth of free and delicious Fuerte avocados.