White Substance On Prickly Pear - Knowledgebase Question

Peoria, AZ
Avatar for mowafay
Question by mowafay
January 9, 2000
I have what appears to be white-hairy fungus on my 2 prickly pear cacti in my front yard. I have noticed an increase in fungus over the past year. I wash it off from time to time with a spray of water from my hose. It keeps coming back.

Answer from NGA
January 9, 2000
It sounds as if you have cochineal scale. The scale insect isn?t noticeable but it secretes a tell-tale sticky, white, cotton-like substance that can spread over an entire cactus with time. I find that a strong blast of water from the hose controls cochineal, although I never seem to completely eliminate it. The more frequently you wash it off, the less trouble you'll have with it. Luckily, the scale won?t hurt the plant as long as it?s kept under control.

I remember years ago when I first hosed off a cholla that had cochineal. I was dumbfounded when the water running off the cactus towards my feet turned bright red! I learned that the insect body (not its white secretion) was traditionally used to make a red dye and many weavers and artisans still collect it from cactus to use in their work.

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:

( No account? Join now! )

Today's site banner is by Baja_Costero and is called "Aloe mawii in bloom"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.