The oleander aphid or the milkweed aphid (Aphis nerii Boyer de Fonscolombe) is the small, little insect, seen in clusters on oleander leaves. They are bright yellow with short black legs. They don't look like an insect at first. They appear to be blobby spots of pollen or seed clusters, but upon closer inspection, they'll move with the wind and their legs will jiggle. This is how I found them.
If you see dark brown ones, that's mostly like a host of a parasitic wasp or other such creature that has deposited an egg in the aphid for the aphid to be consumed or turned into a zombie.
They're most commonly found in Florida or any warm or tropical climate. In my case, it's the desert heat of Nevada where oleader is very popular.
This is an asexual pest. In this instance, most of them are female and do not need a male to reproduce. They can be winged or wingless.
It's most commonly found in Florida or any warm or tropical climate. This pest probably originated in the Mediterranean and has traveled with oleander through the distribution of the plant, although no precise origin has been determined.
They feed on the juices produced by the oleander plant. They love the fresh new shoots of the plant.
They can cause harm to new growth. Leaves can become faded or distorted. They leave behind a sticky dew that attracts ants. The sappy liquid that they excrete can mold causing issues with the host plants photosynthesis.
I found in one article that it can effect citrus. Since I have 2 citrus trees in my yard, I'll be keeping an eye on them.
Sometimes this aphid will transmit viruses to your plant like sugarcane mosaic potyvirus or papaya ringspot potyvirus, but I haven't seen many cases on the web.
From my own research, they are not that harmful unless the population is out of control
The aphid has been known to infest vinca, aka periwinkle. They've been known to feed off of milkweed which their nickname implies. In rare instances, the insect can feed on Hoya.
Repeatedly knocking them off the plant with a water hose seems to be the winning solution. I've done it twice now and it seems rather effective. Since oleander does not need to be regularly watered to survive, not watering the plant at all is a slow way to deter the bugs.
Good old pesticide isn't necessary unless you have a serious infestation. Avoid spraying in direct summer sun, because the leaves could burn. I always suggest a milder alternative like soap or oils like neem. Aphids are soft bodied and are easily effected by these gentler solutions.
Introducing other bugs such as lacewings, butterflies, and lady bugs is a good possible solution. Lady bugs love aphids and you can order them online. You'll have to do more research on this as introducing anything to your ecosystem can have unexpected results. The most common issue is introducing a bug with a disease that infects the same bugs that already live in your yard. Look locally and make sure it's necessary.
For more serious results, you can prune the infected areas and dispose of them in tight plastic bags or burn them. Please keep in mind that burning oleander will emit a toxic essence into the air that can cause serious illness if inhaled. If you choose to burn oleander, make sure you do so in a non populated area.
Deter them with other plants by neighboring them up with the likes of onions or marigolds.