Friday, August 10, 2012

Honeydew! (not the melon...)

Have you stood under a tree recently and felt "raindrops" falling onto you?  Or maybe you've discovered your car or patio furniture covered in a sticky mess?  Or, maybe similar to my're walking the dog and walk across a part of the sidewalk that causes your shoes to stick?  This is all from honeydew and it seems to be covering Central Texas at the moment.

Aphids being tended by acrobat ants.
Honeydew is the plant sugars that pass through the digestive track of aphids, so to put it bluntly- aphid poop.  Honeydew is sticky and can look like shiny droplets covering surface.  When you have a large population of aphids, then more honeydew is produced and that's when things get messy.  To make things even messier, honeydew can attract a fungus called sooty mold.  Sooty mold is black and grows on the honeydew covered areas.

So why all the honeydew now?  Just think of it as the perfect storm for aphids.  Remember back in July when we had all the rain and it was pouring every day for almost a week?  Wouldn't that be nice right about now?  I it's possible that the weather knocked down populations of natural enemies of aphids.  Yes, it would have knocked down the populations of aphids too, but aphids have the capability of reproducing rapidly and they do a much better job and increasing their population than their natural enemies.  When the natural enemies aren't available to keep the population down to a suitable level, the aphid population explodes and goes to town feeding on trees (and other plants) and creating honeydew and causing a huge mess.

If you are dealing with aphids and/ or honeydew right now, I would suggest blasting them with a high pressure water spray.  That suggestion may or may not be feasible for you depending on how tall the tree is that you are dealing with.  Treating the tree with an insecticide to reduce the aphid population is really not recommended, but if you feel that you MUST treat with an insecticide, then please hire a professional that has proper application equipment and BE AWARE OF DRIFT!


Anonymous said...

The result is that "sooty Brown" mold is now covering the leaves entirely, forcing the plant to make new leaves. What's the best remedy to get rid of the mold now?

Wizzie Brown said...

You'll need to first get rid of the aphids and then blast the sooty mold off with a high pressure water spray. Good luck!

pincushion polly said...

Do the aphids like roses? Because my rose leaves all the sudden have brown spots all over and then they turn yellow. I don't want to shoot water on them though because of blackspot.
What else can I do to get rid of them now ?