This tiny insect, the Cottony Cushion Scale, is a friggin’ thorn in my citrus trees sides.
I’ve had two dwarf citrus trees – one lime, one Meyer lemon – for over two years now in the front of my home, and they did great the first year. But then… nothing. Not one little blossom for a year and a half. Nada. Zilch. I looked closer, trying to figure out what was going on and I realized there were missing leaves. At first I thought it was a caterpillar of some sort. And then, I saw a minuscule little white dot on the underside of a leaf. I saw a lot of little dots…
You will also notice that some leaves have curled and the inside has a cottony, sticky residue on them. This is referred to as honeydew. Ants love this stuff so you might now also have an ant problem. This is what some of your leaves may look like:
So what was it? Cottony Cushion Scale had taken over, right under my nose! These little buggers are so tiny and sneaky. And they will ruin your citrus, unless you get it under control. Cottony Cushion originates from Australia and is rumored to have come to the US by accident in the late 1800’s on a plant shipment. The mature insect lays hundreds of eggs which feed off the veins of the leafs and small twigs, sucking on the sap. Eggs hatch faster in warm weather – in just a matter of days – so it’s important to be vigilant if you think you have an infection.
Natural enemies are the best way to control Cottony Cushion Scale: the Vedaila Beetle and the parasitic fly Cryptochaetum. But if they are not in your garden, then try my method: isopropyl alcohol, also known as rubbing alcohol. I spray the undersides of my leaves with it and it kills them on contact without effecting the plant.! Yeah!
Here is a before and after of a mature Cottony Cushion Scale, seconds after spraying it with the rubbing alcohol:
This technique has been a godsend to my trees, and doesn’t have the toxicity that pesticides do. About once a month , I check the underside of the leaves to see how they look and making sure no insects have hatched. I’ll even do a little spraying when I don’t see anything because they are so tiny, and I don’t want to miss anything. I found an easy to use bottle that had a stay nozzle at my local grocery store.
So how will you know your tree is on the road to recovery? New leaves will grow and most importantly, flowers will blossom! I’m happy to report things are looking good this year.