Two Things You Did Not Know about Japanese Beetles

Japanese beetle on roseI’m one of the fortunate few Minnesota gardeners who — at least so far — does not have a problem with Japanese beetles. The JBs can be extremely frustrating and they have driven two of the most peace-loving ladies I know  to near distraction.

There are lots of rumors about what works and what doesn’t work with the beetles. Hand removing works; traps, probably not. But here are two things you may not know about getting rid of Japanese beetles.

A friend of mine has been squishing the beetles when she pulls them off of her roses. This was good therapy for her. Unfortunately, it turns out the beetles emit a scent when they are crushed and — you guessed it! — the scent attracts more beetles.

Another example: Several experienced gardeners have noted that geraniums appeared to be toxic to Japanese beetles. They wondered if putting the geraniums near other plants the beetles like, such as roses or raspberries, would protect those plants.  It turns out that there is some truth to this. According to the University of Minnesota Extension, a substance in geraniums seems to paralyze beetles — almost as if they were drunk. But, like drunkenness, it’s a temporary condition and eventually they recover.  Also, the beetles don’t learn from their mistakes — they keep coming back to the geraniums. Some research even shows having geraniums nearby brings on more beetles.

The good news is, the beetle season in Minnesota is at least half over.

How do you deal with JBs?

Cherry Season: It’s All Over But the Pie

Fresh-picked cherries
I did get a few good cherries.

This spring I blogged several times about my ‘Bali’ cherry tree and my efforts to prevent the blossoms from freezing during our warm/cold/warm/cold April. I’m happy to report that many of the cherries did survive and, in some ways, I had a significant harvest, most of which I pulled off the tree earlier in July.

That’s the good news. The bad news: There were worms in a lot of the cherries. There is a cherry fruit fly that is a threat to cherry crops in many states, and I could have that, though I’m pretty sure mine is the only cherry tree in the vicinity. It’s also possible my tree was infected with the larvae of the plum curculio, a common pest on apples, plums (of course) and other fruits in Minnesota. The larvae look similar in both pests (little white worms), so I’m not sure what the cause is. The lifecycle is also somewhat similar — with flies laying eggs in fruit, larvae eating the fruit (on or off the tree), pupating in the ground, emerging as flies, causing more fruit damage, then laying low over the winter in the soil before emerging to mate and lay eggs.

Controlling for the pests may be challenging — the best organic approach is sanitation. I picked up all the fallen cherries around the tree to make sure none of the little worms matured. (I’ve also been much more diligent this year about picking up and throwing away fallen apples.) Next year, I will consider putting landscape fabric and mulch around the tree to prevent the flies from hatching near the tree. Beyond that, most sources recommend spraying. I will probably give it another year before considering that route.

In the meantime, I did get enough worm-free cherries for about one pie. If we ever get a break in the heat, I plan to bake one and eat my piece very slowly.


Insects Arriving Early

Yesterday I had a close encounter of the delightful kind. I had stopped at Bachman’s Cedar Acres on the way home from the Twin Cities and was looking at some dianthus for a spot on the rocks in my front garden.

While I was checking out the color options, a white-lined sphinx moth flew in and started grabbing nectar from the plants. I didn’t have my camera, so I have no photos of the event. And, anyway, it was one of those moments when you just stop and admire the resourcefulness, the beauty and the diversity of nature. The moth—which is sometimes called a hummingbird moth because it’s that big and looks like a very ugly hummingbird— and I were within a foot of each other for probably two minutes. After a while, a snowberry clear-wing hummingbird moth flew in to enjoy the nectar, too. If you have never seen one of these, it looks like a bumblebee that was in a nuclear accident.

It was a joy to watch both of the moths move from flower to flower, inserting their proboscis into the blooms, then buzzing to the next flower.

After the moths departed for another flat of flowers, I thought about how early this was for me to see them. That may be a function of my plants rather than the moths’ behavior, but usually I do not see them until August and the only blog reference I have to them is from October!

At the same time, the University of Minnesota Master Gardener list serv that I read is full of references to early sightings of insects: sawflies, black aphids, ladybugs, four-lined plant bug, spittlebug, etc., etc.

What insects have you spotted this year? And, is it early for them to be in your garden?

Return of the Eastern Tent Caterpillars

I first noticed the tell-tale tents of eastern tent caterpillars (Malacosoma americanum) in the nature area near our house about a week ago. Sure enough, when I did my post-freeze assessment of the backyard, a tiny nest was clinging to one of the apple trees — although it looked like no one was home.

Eastern tent caterpillars have been regular visitors to our yard in the spring. Usually I wait until dusk when all the caterpillars have returned to their nest and then snip the branch with the nest off and dispose of it. Eastern tent caterpillars are a nuisance, although if left unchecked they can defoliate a tree. They are not to be confused with forest tent caterpillars (Malacosoma disstria), which are sometimes called armyworms. Unlike eastern tent caterpillars, forest tent caterpillars do not build a tentlike nest. They also have different food preferences. While eastern tent caterpillars feed on apple, cherry and plum trees, forest tent caterpillars like aspen, birch, basswood and oak.

If you are not sure what kind of creepy crawly you have, check out these government fact sheets on forest tent caterpillars, eastern tent caterpillars and just for fun, gypsy moth caterpillars.

I did not remove the nest from my tree yet, because it’s possible the freezes we have had the past few nights did the caterpillars in for me. If not, I’ll be snipping the tent soon.