Hard spraying with water. Multiple times. That usually dispenses with the aphids. If after 3 sprays, you're still heavily infested, you can then resort to Neem in the evening (after the bees have gone back to the hives). And yes, in our ridiculously dry weather out here, spraying your trees is very, very good for them. Removes dust, critters, improves transpiration and removes a more favorable environment for certain pests (like red spider mites). If not, then no tree would tolerate the frequent rains we usually get this time of year.

Patty S.

After blasting the entire plant with water to clear out the tresspassers, you may want to snuggly wrap a couple rings of 1" masking tape around a smooth area of the lower trunk with the sticky side facing outward. Insects walking across the tape will commonly get stuck on the tape, or may simply avoid stepping on it. The glue will gradually lose it's effectiveness, so just replace the rings when they are no longer sticky. If you have small lizards, it would be good to check the rings each day to see if any need help to escape.

Great advice... will do both of these today!!!

And maybe equally important, you probably need to control your ants. In citrus, almost without exception if you have aphids, you have ants. Control the ants and the aphids will be a very small problem or none.

For my garden trees I just hose off the aphids; for my field trees, when I see aphids I get after the farm manager to control the ants.

Best take-away from a recent course at the local botanical garden was a cheap, simple, non-toxic control of soft-bodied insects in greenhouses. Aphids, white fly, 'crawler' stage scale and the like. Using a quart-sized sprayer bottle, add a cap or two of isopropyl alcohol and a drop or two of Dawn detergent as a surfactant. Swirl to mix...don't shake. Spray. Repeat as necessary...but as mentioned above, integrated control is the key. Aphids usually mean ants that 'tend' them.

Cheers