Archives for posts with tag: rose chafers

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We’re ebbing towards the end of the rose chafer season. Part of me wants to claim at least a partial victory. Not that we didn’t suffer losses; we did. But we appear to be making progress in our annual war with them. Unlike last year, no trees were completely defoliated. That’s an improvement. And, we discovered that intense garlic spray can go a long way in protecting the trees. Next year, we’ll spray earlier, to give the orchard advance protection. It doesn’t eliminate them, but it appears to limit their numbers.

But it’s difficult to truly ‘know’ if we are making progress. We are only one small orchard. The main part of the orchard has only a dozen trees–none of them the same variety. Our tree mix is a complicated blend of what we like, what will grow here, what is needed for pollinating each variety, and timing, what will provide harvesting throughout the season. There is no way to do any kind of an A/B comparison, no control group, no double blind. Beyond that are the imponderable intangibles–weather and whatever other factors dictate the rose chafers’ numbers from year to year. We can only do what we can. And then there’s the open question of climate change–will it make insect issues better or worse? I even wonder if my manual efforts (daily bug squishing) could make a difference from year to year in the population. After all, through the season I am killing thousands of rose chafers. Does that play forward into the next year’s numbers? There’s no way to know.

One longs for the rigors of true science: single factor differences and the ability to identify true cause and effect. Sigh. It’s that Chinese curse, “May you live in interesting times.” I have my own version, “TDMV.” Too Damn Many Variables. It’s the answer to so many of life’s current vexing issues. We just have to do the best we can, and recognize that we have no control.

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The problem is that there is no money in it. We’re struggling to find effective treatments for the various six-legged monsters that attack our fruit trees. We vehemently refuse to consider ‘standard’ agricultural poisons. Left to our devices, and the blessings of the internet, we are making progress. It’s slow, but we’re in no hurry.

Last year we suffered a plague of rose chafers. It wasn’t just us, the entire county was inundated with them. They are an annual problem–but not like that. We used our standard, herb-augmented, insecticidal soap–but they are beetles, and thus, armored. The soap helped, but was not fast enough to prevent them from damaging our trees. Though all the trees were affected, the plums were the worst. I was beside myself–and for weeks, visited the orchard up to five times a day–to hand crush the bastards between my fingers, by the hundreds. All over the county, farmers were alarmed by the onslaught. Most fought back with pesticides as deadly as the bugs themselves. I won’t do that, on principle, and because I keep bees. I know the costs of indiscriminate pesticide application. Bees are insects, too.

From an organic perspective, we do not want to coddle our trees. There’s wisdom in allowing some predation. The trees will respond by growing foliage that is less delicious, even bitter–at least from a bug’s perspective. And that change carries forward, year to year. Most of our trees are young, and too delicious for their own good. Modern fruit has been bred to be sweet. It’s its attraction and its Achille’s heel. Last year, two plum trees were completely skeletonized–defoliated. Though they did leaf out again after rose chafer season–it’s not a performance they can repeat year after year. So, we were curious, after last year, to see how the trees would respond this season to the annual rose chafer offensive.

This year, we are armed. If things get too bad, we have purchased the tree netting, which is the ultimate in protection. And we’re refining our organic spray options. But first, we are trying to be observant, to learn from the bugs and the trees.

The infestation is not as intense as last year. We have no insight into that–it’s a ‘too-many-variables’ situation. Last year was the thing that inspires nightmares and horror movies. This year, not so much. But, I was talking to a clerk at our local farm and garden store–and he was reporting rose chafer levels like we experienced last year. He had that overwhelmed tone to his voice. He reported that his wife wouldn’t even go outside. Perhaps our trees are not so delicious as before? Also, though the plums are still the favorite victims, this year the rose chafers are also going after the apples, and even the pears. Are the plums learning to defend themselves?

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In my research, I seen suggestions that intense garlic applications may make a difference. The theory is that the sulfurous elements in the garlic are absorbed by the leaves, and after a couple of days, become a systemic–discouraging the fine palates of our insect predators. Although I’d already done my pre-season mint and light garlic spray, once the rose chafers arrived I decided to give intense garlic a go. It’s working. That doesn’t mean that the pests are gone–but, since the spray three days ago, the levels have dropped to about a quarter of what we were seeing before. Of course, I have no way of knowing if weather, or seasonal variations, or even astrological influences are a factor. We are only one small orchard–with no control group. But, anecdotally, it’s working. We may try one more application in a week or so–if the numbers go back up.By the first week of July, the season ends and we can breathe a sigh of relief. Given that conventional farmers confronted with such an infestation will spray weekly with really toxic compounds, I’m feeling pretty smug about the garlic. Unfortunately, there’s no economic incentive to research the impact of garlic. There’s no patent…no way to milk money out of the bug-traumatized gardeners.

Next year, we’ll remember to start the intense garlic before the rose chafers arrive, to give the trees advance protection. I’m always perusing the internet for solutions–and I note that there is a product, ‘Garlic Barrier,’ offered to combat beetles. It’s probably much easier to use than my messy process of pulverizing heads upon heads of garlic, filtering it and then mixing it in water and a carrier oil. But my method was a lot less expensive.

We’re also looking at applying beneficial nematodes to the soil in the area. These microscopic warriors seek out underground larvae and eat them from the inside out. It might be of limited use, because, after all, rose chafers can fly. Who knows how far they come to eat our orchard? That plan would be for next year–to minimize their numbers, even before they leave their winter homes. It would also limit other forms of grubs, which can be pests in the garden. Every little bit helps.

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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.

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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.