Aphids are causing a gooey, sticky mess in North Texas yards. Here’s how to clean it up

I was out walking Zeus the Dog a couple of weeks ago and I realized my shoes were peeling up from our driveway each step that I took. I felt like I was walking through drying varnish.

Well. I’ve been around this block a few times before, and I know the story. Little insects no bigger than pinheads are camped out on our giant pecan trees. They’re sucking sap out of the leaves and processing it through their tiny aphid bodies, sending it out as sticky, gooey fluid called honeydew.

If you go out in the morning or evening and look toward the sunlight you’ll see a fine mist falling from the trees. That’s the honeydew. If you stand there long enough, you, too, will become shiny, sticky and gooey — just like your plants’ leaves, the patio furniture, cars, walks and everything else within the fall zone of the trees.

I’ve been around these parts for more than 50 years. Like I said, I’ve seen this happen before. But I’ve never seen it like this. We’re a mess. And it’s not just the pecan trees. It’s oaks, crape myrtles and a whole host of other species. Each is being attacked by its own species of aphids. The insects may vary slightly, but the outcome is exactly the same. But pecans lead the pack.

Here are the facts …

Some of these are rather odd (like they’re out of a Halloween movie), so do read on!

▪ Yellow pecan aphid. Monelliopsis pecanis. If you want to read up on it, use those as key words in your internet search and add in the additional word “university.”

▪ The female aphids give birth to living young without mating. Up to 30 generations may develop in one growing season.

▪ Beginning in September wingless females and winged males develop from some of the nymphs. They mate. The wingless females lay eggs for overwintering in crevices in bark of trunks and limbs. The eggs hatch in April.

▪ Aphids have characteristically pear-shaped bodies with twin “exhaust pipes” extending from their back sides.

▪ Aphids are pinhead-sized (approximately), and this species is yellow with brown markings. Other species can be orange, red, black, green or white. Giant bark aphids, which often spew honeydew during the winter and early spring, are much larger. Curiously, however, most of us never see the aphids on trees. They’re too tiny and they’re up way too high.

▪ They are communal insects, so expect to see dozens together, if not more. They will be on both top and bottom leaf surfaces.

▪ Feeding can begin in early to mid-summer. This year it became extremely heavy after the rains of late August.

▪ The main problem yellow pecan aphids cause is the deposits of honeydew all over their surroundings.

▪ As a secondary and equally annoying issue, sooty mold fungus grows within the honeydew substrate. It soon leaves a black matte growth across what had been the sticky surface. You’ll see sooty mold on leaves, twigs and trunks of crape myrtles, pecans and other species as well as anything beneath the afflicted plants.

▪ The honeydew itself is water-soluble, so a heavy rain will usually wash it away. That assumes it will rain before sooty mold gets a good start growing in the sticky surface.

▪ You might be better advised to wash your drive, patio, walk and any other sticky surfaces soon rather than waiting.

▪ It may even take warm, soapy water and a mop or soft scrub brush to get rid of any mold that has gotten a start. Power washers also work well, but be careful that you don’t use too much power and blast finish off your furniture in the process.

▪ In case you were wondering about spraying to control these multitudes of aphids, it’s too late in the season for that to be of much help. Their feeding will soon be done for this year. Leaves of the affected plants will soon fall. There isn’t much justification for applying any insecticide now. You’d be better advised simply to blow the area clean of fallen leaves, then spray water to clean up the stickiness. If the problem starts to appear next year, and if it’s earlier in the season, general-purpose insecticides labeled for control of aphids could be used at that time.

One other related comment based on half a century of helping gardeners of North Texas: Problems like this that suddenly pop up out of nowhere happen all the time. One year it’s pecan aphids. Another year it’s armyworms. Or grasshoppers. Or white grubworms. They all have their moments of glory. Usually the affected plants survive the attacks and come out the other side intact, no worse for the wear. Keep that in mind before you hit the panic button on any one of them.

You can hear Neil Sperry on KLIF 570 AM on Saturday afternoons 1-3 p.m. and on WBAP 820 AM Sunday mornings 8-10 a.m. Join him at www.neilsperry.com and follow him on Facebook.

This story was originally published October 7, 2022 at 5:30 AM.