Aphid Rain: That’s not sap coming from your Texas Pecan trees. It’s aphid excretions, yay!

So here’s another fun problem to look out for, but only if you have a pecan tree nearby: Aphid Rain. (I think I made that term up, but maybe there’s something more scientificky.)
I first noticed my car literally covered with small sticky droplets and thought it might have been nectar from the Crepe Myrtle flowers overhead. Then I noticed similar droplets on my plants’ leaves, table, deck…pretty much everywhere in my backyard where there is no Crepe Myrtle in sight.

Aphids, circled
Aphids, circled.

BUT there are Pecan trees. In our front and back yards, and I assumed they were exuding some kind of excess moisture or ‘sap’ from their leaves. Today I discovered I was unfortunately way off.

Nope. It is aphid secretions. I innocently searched ‘why is my pecan tree dripping sap’ and ‘sticky stuff under my pecan tree’ and found dozens of newish entries reporting the culprit is indeed aphids.

Pecan trees are everywhere in Houston, and the biggest problem I’ve had with them in the past is squirrels feasting on the unripened nuts and dropping them with a heavy thud where they splatter their juice that can leave brown stains and cause physical damage to a delicate potted plant below. Or a laptop. (Raising my hand meekly.)

Over the last month, I’ve noticed my leafy plants under the backyard pecan were being covered in clear sticky droplets. I hosed them down which seemed to help, but the goo kept coming back. Our sealed concrete patio floor also feels sticky to walk on.

Aphid secretions on Cissus leaf. Ugh.
Aphid secretions on Cissus leaf. Ugh.

Today I found several articles confirming that aphids in Pecan trees are indeed a problem this year, possibly due to the drought. Lack of rain to wash them from the trees along with climate conditions that aren’t friendly to aphid predator growth has created the perfect situation for these sticky bastards to thrive overhead.

Aphids feed on the leaves’ juices and excrete (we’ll just say poop, because that’s what it is) that sweet secretion called honeydew. Black sooty mold is one fungus that feeds on honeydew and can be quite damaging to our plants.

As far as treatment goes, I’m just going to ride it out. There’s no way to reach all of the leaves and not enough time to treat the tree from the inside out before all of the leaves drop with the changing season. Any chemical treatment will probably hurt the beneficial dudes and I don’t want to harm the only thing helping!

In the meantime, I’m going to continue hosing down my plants and encouraging beneficial insects I find to partake in the buffet among the branches above.

Funny enough, I’ve noticed a lot of Lacewing eggs around, and of course their larva are very helpful when it comes to controlling aphid populations.

In fact, when I picked up a fallen stem of pecan leaves to inspect, the first thing I saw was a little Lacewing larva, and on closer inspection, there were several small yellow aphids on the leaves. Fortunately, I have not seen any on my succulents but I am not putting it past their sappy butts, so I’m keeping a really close eye on everything.

And I almost didn’t mention this, so please don’t hate me… you can actually see the stuff falling from the trees. It looks like a light mist of rain when the light catches it right…

The good news is I just went to try and find another Lacewing larva to get a picture and I saw two ladybugs high up in the leaves, and they were on a mission!

I hope this helps anyone who is wondering why our Pecan trees are making such a mess. It might be a good idea to pre-treat next season, but I will follow the experts’ advice for now and let nature take its course: ‘“They’re cyclical and will go away but seem to have come out of the woodwork after the last few weeks of rain,” he said. “We typically tell people to leave them alone because we think the damage to trees is minimal and sprays can actually make things worse.” Larry Stein, Ph.D., AgriLife Extension horticulturist.

More sources:

Sticky, Gooey Mess of Pecans– neilsperry.com

Texas Crop and Weather Report ‘Yellow aphids a sticky situation’ – agrilifetoday.tamu.edu

How to Identify and Control Pecan Aphids – noble.org

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