Archives for posts with tag: insect pests

It’s a challenge, every year, to get tree care tailored to the orchard’s needs. Our trees were selected for early, mid, and late season harvest–with some overlapping pollinators. Unlike a larger scale orchard, these all bud, leaf, and blossom at different times. Spring care is a crapshoot, in any event, doubly so for our motley collection.

We do spray–but we use organics. For early season care, we do two dormant sprays–the first is just a food-grade mineral oil, and the second is food grade mineral oil and garlic. Timing the first is easier; it can be done anytime when the tree is dormant. (Though, preferably not when things are freezing, or wet, or…. or.) It’s also helpful if you can nab a two-day window following, without precipitation. And, of course you want to avoid spraying in a high wind. Even with organics where overspray is not a toxic issue, spraying in the wind is just a waste.

This year we had weird weather–a rolling month of warm days and freezing nights. It confuses the poor trees. They’re inclined to bloom (and some did), only to lose the blossoms to the freeze. This won’t be a heavy fruiting year. And, you need to watch that those freeze damaged blooms don’t become a pathway to disease–like fire blight. You have to be ready to prune off branch tips that wither or turn black. I’m especially keeping an eagle eye on the pear trees, as they can quickly succumb to neglected fire blight damage. It appears that freezing is no longer a risk. But warm weather, and its attendant bug-load has come on fast, nearly tripping over itself to invade the orchard.

The mineral oil acts as a barrier, smothering eggs left on the tree from the last season and then killing and dissuading the early spring pests. The challenge each year is to time the second spray. Too early and you’ve wasted the effort. Too late and the bugs get a foothold. This year, the leaf-rollers have got ahead of me on two of the trees. Leaf-roller is a generic term for those little caterpillar larvae that hatch early and then make tiny tents out of the emerging leaves. I have at least three different varieties. I don’t have a window of weather opportunity for my second spray until Thursday. In the meantime, I’m taking attendance and squishing them when I see them. And I go out every other day or so, hunting them down, gently opening up their tents, to avoid damaging the tender leaves, and killing them. You can spot them easily enough by the bent-over foliage.

A real farmer, with an orchard full of trees, couldn’t possibly babysit like I do. I understand why they spray poisons. We laugh about how the local cherry farmers are always whining about the weather. I can afford the time to avert the worst of the infestations, and I don’t need market-perfect fruit. Even with the weird weather, things don’t look too bad so far. Maintaining an orchard is just like comedy, it’s all in the timing.

My biggest challenge is the rose chafers. We lost a plum tree to their damage last year, but this year, we’re ready. We bought bug-netting, and we’re going to wrap them like lollipops. So there!

rose chafer

It’s the same every year. Except this year. The first week of June brings verdant growth in the garden. And, it brings rose chafers. Rose chafers can be the bane of a gardener’s dreams. My crazy neighbor blamed me and my long vacant property for her rose chafer woes. I thought she was nuts.*

In my first years here, I didn’t know what they were. I had to do research to identify and find defenses to these voracious pests. It’s best to know your enemy. Rose chafers, true to their name, love rose plants–their leaves and their tender, delicious petals. I resolved early to avoid planting roses. (The deer love them, too.) Roses were definitely not worth the headache. Unfortunately for us, rose chafers thrive in sandy grassy meadows and their tastes are not limited to roses. The female digs into the sand to lay her eggs, which hatch into larvae and develop, eating roots. They emerge in June, as adults–ready to chow down on your precious leaves, mate, and start the whole cycle over again.

In my case, the garden plants are not too badly targeted–it’s in the orchard where I see the damage. Initially, I convinced myself that ‘handpicking,’ the organic gardener’s first line of defense, would be adequate. I mean, how bad could it be? They’re just bugs, and their entire life cycle happens in a scant three to four weeks. Left unchecked, rose chafers (who are leaf-suckers) can skeletonize a tree’s leaves. Not good. But moderate predation is not a bad thing…over time, a tree will make its leaves more bitter, to fend off the attackers.

Handpicking could be a full time job. These little buggers have wings–and even if you could kill every one in the orchard, new ones will fly right in to replace them. Not that I didn’t try. I’d go out, several times a day and squish every rose chafer I could reach (another limitation on hand picking.) This could easily average 30 to 50 bugs per tree, with the plum trees being most heavily afflicted. They love those plums. Last year, my sister visited. She was horrified that I was squashing the bugs in my bare hands! Gross! But then she returned home and found them eating the flowers in her garden and promptly stepped up to her full potential as a cold-blooded rose chafer killer.

There are some built-in killing efficiencies, tied to the bugs’ short lifespan and behaviors. In their adult form, rose chafers have only two objectives: breeding and eating. More often than not, they do both, simultaneously. That way, I can kill them in ‘the act,’ which adds the satisfaction that you’re eliminating the next generation at the same time. I’m not sure if it speaks to their biological imperative, or to the males’ ineptitude as lovers, but the females don’t even stop munching when mounted. I can almost hear them, “Whatever…just don’t interrupt my meal.” Since it’s the munching that causes the damage, I wish their romantic efforts were more of a distraction.

There are alternatives–everyone is enamored of pheromone traps. They are non-toxic and draw their victims in with floral and sex attractive fragrances. They certainly are effective on yellow jackets and hornets. But, the downside of pheromone traps in an orchard setting is that they may actually bring the pests in droves. (I suppose it’d be good if you could put the traps in the neighbor’s yard, far from your own precious plants.) I read that sometimes the traps would be so effective, that you’d have difficulty disposing of the buckets of insects attracted. Yuck. I’d read that, in some cases, netting could be necessary. I checked the priced on agricultural netting fabric and balked. Those tree nets could run $60.00 per tree! So I reverted to the organic gardener’s second line of defense, soap spray.

You simply mix a couple of teaspoons of liquid dish detergent and water into a standard hand pump sprayer. To be effective, you need to get the bug pretty drenched. I’ve become an expert marksman with the sprayer. I can blast the little bastards right out of the air, as they try to land on my trees. This method has some of the same disadvantages as handpicking–you have to stay on top of it, several times a day. But it’s much faster, so, in an average situation, you can keep ahead of the chafer damage.

This is not an average year. In desperation, I started checking online to see if others were experiencing similar plights. Rose chafers are also pests to grape farmers. Here in Leelanau County, we have a growing wine industry. The MSU (Michigan’s Ag University)    site indicated that one or two rose chafers per branch was a tolerable level. But this year, Leelanau grape growers have reported up to 200 insects per branch! Not surprisingly, many are reaching for toxic pesticides. Not me.  My poor plum trees are not that infested, but I’m not keeping up with the damage. I’ve already given up on getting an actual crop–at this point my objective is to save the plum trees. (The rose chafers have only a passing interest in the apple trees–and no interest whatsoever in the pears.) There I am, up to four times a day, blasting away with my soap spray.


It won’t go on forever. Just until the end of the season (three or four weeks), or until the nets arrive…whichever comes first.


*Well, she is nuts. But there’s some minimal truth to what she says. Were we to cultivate the entire field, it would disturb the sand–and the eggs and larvae. So, by leaving it natural as habitat, we are contributing to the rose chafer’s success.