The Bonsai Dilettante

Bug Warning - Goldspotted Oak Borers

"Why didn't Noah swat those two mosquitoes?" ―Unknown

And for that matter, why didn't he swat the Goldspotted oak borer?

Agrilus auroguttatus is an invasive pest contributing to the ongoing oak tree mortality occurring on federal, state, private, and local Native American lands in Riverside and San Diego County. If you have California Black Oak or Coast Live Oak, you need to watch for signs of this pest. Evidence of an infestation may include a weakening of the top of the tree or small “D” shape holes in the bark. As the weather warms, the insects exit the trees. They lay larvae that feed beneath the bark of oaks and damage the movement of nutrients in the tree. They do not kill the tree quickly, but they will weaken the tree and eventually kill it.

There are currently no effective tools for protecting trees once infestation occurs.

The only good news is that entomologists believe that trees larger than 20 inches in diameter seem more susceptible to them.  Officials are still testing to determine if any insecticides are effective against this pest. If I find it in any of my oaks, I'm going to seriously consider burning them and isolating any other oaks that do not yet show signs of infestation.

We Come to Snuff the Looper

“There is nothing in a caterpillar that tells you it's going to be a butterfly.”― R. Buckminster Fuller

or an ugly gray-brown moth, like the looper turns into. My bougainvillea have been introduced to some loopers. Loopers (disclisioprocta stellata) are green or brown caterpillars that dine on the foliage of bougainvillea. These inchworms look like bougainvillea stems, allowing them to camouflage themselves well. They are hard to avoid. The adult moth lays eggs on the underside of the leaves and the first sign you have them is when your leaves start exhibiting the scallop-shaped indentations of its bite marks. If you see this, and especially if you also see tiny black balls (looper poop) on the leaves, you have loopers.

They hide during the day and feed at night. The juveniles chow down on tender shoots and young leaves. Older loopers munch on mature leaves. They won't kill the plant, but they can defoliate quite a bit of the greenery and what remains will be ugly. Sometimes you can find them with a flashlight at 9 pm, and then you can kill them manually. More likely, you'll need pesticides. Bacillus thuringiensis will control young loopers, but may not work on older ones. Spinosad works against young and mature loopers. I've had success before using diluted neem oil. It smells foul, but it works.