Q. I have oleanders in my backyard and noticed some yellow bugs on the flower stems. What are they and how do I get rid of them?
A. These are highly specialized yellow aphids simply called “oleander aphids” because they have adapted to feed on the toxic plant juices of this plant. They might be poisonous themselves because they drink so much of the oleander fluids.
|Oleander aphid is not as common in the Mojave Desert as it is in wetter places like Florida or Louisiana. There are different aphids for different plants and they don't necessarily switch plants. There are some aphids that are general feeders and other aphids that have developed a tolerance for toxic plants juices like oleander. http://entnemdept.ufl.edu/creatures/orn/shrubs/oleander_aphid.htm|
Different strokes for different aphidsAphids can be red in color, green, brown, black and in your case yellow. Some aphids are general feeders like the green peach aphid and can be found sucking plant juices on a variety of plants while most are very specific, like yours, only feeding on oleander.
Control is the same for all aphids. The products with the least impact on human health are soaps and oils like Safer’s Insecticidal Soap and Neem Oil.
|This is my picture of Neem Oil produced by Monterey. You might be interested to know that there are different qualities of Neem Oil out there. Some neem oil is coldpressed for extraction, some is hot pressed and some is extracted with chemicals.|
More information on neem oil
The National Pesticide Information Center has developed an information sheet on Neem Oil you might find interesting to read.
Look here for Wikipedia on Neem Oil Uses
Other more potent and specific chemical controls are the general garden insecticides like pyrethrin products. These products last longer after you spray so they give long lasting control while the soaps and oils must be sprayed more often and only when the problem occurs.