Cactus Parasite

[Tom]

Any one know how to get rid of this?

Its called Cohineal Scale. Its an insect and some of my opuntia are infested with it. Scientific name is Dactylopius coccus.

There's all sorts of great info about how Native Americans used it to make this great dye, but nothing on how to kill it. At this point, I don't care about feeding out the cactus, I just want this stuff dead and gone.

I've tried: Periodic manual removal, soapy water, vegetable bug sprays, hose blasting and ant and roach killer sprays. They seem to be indestructible.

 

[Fokkerdon]

Yep,wood alcohol does the job. Spray bottle since that got so far established, is best if you can catch this stuff when just a few of the small brown scales.
If you have multiple plants in that area, sometimes is best to just remove the infected one as this stuff can spread easily.
Seems to happen more often with plants that receive more frequent water than those that do not, least in my experience here in Bako.
Hope that helps.
Don aka Fokkerdon

 

[Yvonne G]

Go to Lowe's or Home Depot and look around in the bug killer section. Buy a systemic bug killer. Either liquid or granules. You dig the product into the dirt around the base of the plant and the roots take it up, killing the bugs sucking on the plant.

Anyone reading this should be aware that if you use any type of systemic, you should not use the plant as food, as it is now poison.

 

[Fokkerdon]

Good point Yvonne, that's why I use the wood alcohol as it does not make the plant un-usable for a food item.

Go to Lowe's or Home Depot and look around in the bug killer section. Buy a systemic bug killer. Either liquid or granules. You dig the product into the dirt around the base of the plant and the roots take it up, killing the bugs sucking on the plant.

Anyone reading this should be aware that if you use any type of systemic, you should not use the plant as food, as it is now poison.

 

[Tom]

If I just chop down that lot of opuntia, and completely remove it, how long will it take the little buggers to die off so I can replant in that area? I've got other uninfected stands that I can feed from and a whole bunch of new, uninfected pads to plant elsewhere.

 

[Fokkerdon]

I really don't know Tom, my understanding is that they don't live in the ground but rather the young wingless females float on the wind and once attached to a pad, they stay there for life?
Have heard suggestions to just remove the worst infected pads, high pressure blast water off the rest, I did the wood alcohol on light infestation and removed heavy pads from another that I wound up removing all together.
So far, knock on wood, the only area I have problems with is the opuntia ficus indica that is on the corner of my garage that lacks early morning sunlight and is also the one that flowers late, forms the apples autumn and they ripen in November, staying red on the pads until mid to late next summer (when I leave some on, most of them come off mid spring as treat for the deserts.
http://www.gatescss.org/Pests/Opuntia Pests (hopefully) a dying memory.htm has a bunch of info on different opuntia pests, mostly for Mexico, but something there might help?