The weather in my neck of the woods has got me climbing the walls to get out into the garden and do my thang. But… it’s too wet to work in or with soil, and to wet to burn yard waste; the temperatures are so low that working on outdoor projects means bundling up in my down parka against the cold.
Well today is my birthday, darn it! I’m old enough to go outside and play in puddles without my coat, hat and scarf if I wanna. So, I bundled myself up and Got Out There to Enjoy My Garden Today Come Hell or High Water.
And it is a lucky thing I did. While admiring the newly finished “no-no-doggy-don’t-lift-your-leg-here” fences I installed last week around my second year plum trees, I noticed something new: the leaves of one of the plum trees were sending out, “we need a little bit of help over here” distress signals. The new leaves on the ends of the slender branches were lighter than they ought to have been (new leaves are often lighter in color than older leaves… but these were pale, not just “light”). Plus, they looked… well… sort of kind of “deflated.” Yes, that’s the word I want.
Just to be sure that the leaves were looking “off,” I glanced over at the other plum tree, which stands 8 – 10 feet away. By comparison, its new leaves are dark green, full of gloss, and sass, and “oh yeah, we even flowered this spring!”
What in the world??? thought I.
Frowning now, I step inside the fence to examine the ailing tree more closely, and got a wonderful surprise: a sixteen spotter Lady Beetle (!!!) had hunkered down (rather sodden, poor thing) in the crotch of the plum twigs! I’ve seen Lady Beetles with spots ranging from 2 – 10 in my yard. Today’s is the first sixteen spotter I can remember ever seeing.
The Lady Beetle sighting is a surprise to me because the weather around here feels like March, even though it is almost May. 48 – 55 degree days with non-stop rainfall, and the Mississippi, Illinois and Ohio Rivers up out of their banks and in the cornfields. It doesn’t make a person think “May” and of insects out there in the ecosystem doing their ecosystem business.
A sixteen spotted Lady Beetle crouched in a tree is like a scarlet and black cheetah crouched on the savannah. If you see one hunkered down in the crotch of a tree on 48 degree rainy day, it must be hunting something sho’ nuff worthy of the trouble. What was it hunting? I turn over one of the wan leaves. What do you think I saw? A whole herd of gazelle!
Forget about scientific interest or my romantic love for the natural world. I snatched my hand back from the leaf with a yelp. Blech! Eww! Gross! An aphid infestation! Forcing myself to woman-up, I don my Big Gurl Panties and lean over the little tree again, determined to examine the extent of the situation, which turned out to be not-so-very good. Black (sodden) aphids were crowded along the main veins of each new leaf on the tips of new growth branches.
Did you know that aphids are born pregnant? That thought provides me not a little bit of comfort when I contemplate the trials and tribulations of having been born a human female. At least I wasn’t born pregnant.
Never mind. This business with the aphids is worrisome. The plum tree in question had survived last summer’s blistering drought. It broke dormancy under 14 inches of rain. The fact that it did not bloom when it’s neighbor did, the fact that it has a pest infestation while its neighbor does NOT makes me think that this tree is systemically distressed. It isn’t mere “chance” that the aphids are in this tree. This tree is weaker than the others in the yard.
Normally, aphids aren’t deadly to a healthy tree, though they can produce unsightly results and reduce the total harvest. I am more concerned that they will vector fungal infection to the plum tree, and possibly even spread it to the other fruit trees in the yard. What with summer humidity so very high in the Great Plains States, all stone-fruit trees grown here are particularly susceptible to fungal infection.
This development concerns me. I happen to have a bottle of insecticidal soap laced with pyrethrin in my garage. It is a year old and has never been opened. I am not one to waste money, and this seems like a perfect opportunity to get my money’s worth.
I’m going to spoil the story at this point and just tell you: I finally decided against chemical intervention in this particular situation. Why?
Ultimately, because aphids are born pregnant…and because Lady Beetles are not. They lay eggs in little clusters, never more than a dozen (if that) right smack in the middle of aphid infestations. And although this Lady Beetle had surely been gorging itself on those luscious, soft-bodied little critters (ugh) I think this Lady Beetle is a she, not a he, and has laid eggs in the midst of this infestation. Lady Beetle larva out-gorge adult Lady Beetles, taking down 400 – 500 aphids per day in order to fuel their metamorphosis. Although it might be several more days, the non-chemical solution to the infestation has already arrived.
If I spray now, I will surely kill a lot of nasty aphids. But I know (from bitter experience) that I won’t get all of the little stinkers. I won’t get in the nooks, crannies, crevices, or beneath the icky, sticky stacks of insect bodies thoroughly enough to cancel out the grisly fact: each aphid that survives is already pregnant with thousands of copies of itself. One blast of spray, I kill the Lady Beetle, I kill her little clutch of eggs, I kill a half-dozen larvae, leaving the tree utterly unguarded against tens of thousands of aphids just waiting to repopulate the tree.
Prey animals make babies fast, furious, and in huge numbers. Predators make babies in small numbers and much more slowly. Insecticidal soap, in this case, is guaranteed to violate the very calculus that makes ecological economy work. If I intervene, I am setting myself up for having to intervene for the rest of the summer, every 10 – 14 days, like clock-work. Just like it says on every. pesticide. bottle.
Don’t get me wrong, if the tree looked sicker, if there were no evidence of immediate predator response, if this tree were going to fruit and I wanted to show the fruit at a county fair, if the population of aphids were clustered around the older leaves in addition to the newer leaves, I would reconsider the insecticidal soap. If… if… if… I have insecticidal soap in my garage for a good reason; but just because I happen to have a hammer, I am not compelled to hit somebody with it.
There are non-chemical interventions I can try that won’t violate the calculus of the ecological economy:
One: keep the durned ants out of the tree. Ants are famous for “farming” aphids. They care for them, groom them, move them around to new locations, and defend them by driving away (or eating) aphid predators. In return, they are able to harvest a feast of sugary “honeydew” excretions produced by the aphids. What a great symbiotic relationship!
To interrupt that relationship, I’m going to Tangle Trap all the trunks of the fruit trees in my yard. Tangle trap is a glue-like substance that prevents insects from crawling up the trunk of trees into their canopies.
Two, I’m going to prune the most heavily infested tender new green growth out of the tree. Pruning, rather than spraying, gives the Lady Beetle larvae the chance to complete their life cycles, while allowing the tree some relief from its vampiric visitors.
Third, I will watch this tree like a mother hen, as well as the other nearby fruit trees, for pest infestation and fungal disease. I will also be very strict with myself (as weather conditions allow) not to miss any fungal treatments for the duration of the anti-fungal spray period.
Try to remember: ecology has a sort of economics to it, a balance sheet of predators and prey. Before you resort to the crude inelegance of chemistry: Stop. Look. Listen.