Prickly Pear - Cottony looking pest.

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Prickly Pear Pest
If you live in the Tucson area for very long you're bound to run into some of what I like to call cactus snow on our abundant native prickly pears. The cottony looking stuff looks like it might be a fungus or you might think some Avra Valley farmer was harvesting cotton when a gust of wind blew it onto the thorny pads of the prickly pear. The cactus snow is actually an insect - the cochineal scale insect Dactylopius coccus. The bug can be found underneath all the snowy fluff.

Small infestations aren't all that bad and you can learn to live with the somewhat unsightly fluff. Large infestations, which I've seen in some areas of Tucson at certain times of the year, can actually damage the cactus as the insects suck the life from the pads.

Now, before you try to go out and melt the snow off your prickly pears you might be interested to know a few things about cochineal. In earlier times the female insects were scraped off the cactus pads, dried in the sun and crushed into a powder which was transformed into a bright red dye. I'm assuming the males were scraped off as well to suffer the same fate. Guilt by association. Supposedly the dye is what used to give the beverages Campari and sweet vermouth a ruby color.


Cochineal insect on a prickly pear pad.	The same pad several months later.

Eventually other dyes replaced what was at one time the main source of red dye in the world. Cochineal is still produced in South America and sold for use in textiles, foods, and cosmetics. In the future I'd be careful of drinking anything bright red in color and referred to as bug juice because it just might be what it's called.

All the above information is really nice if you're a trivia buff but if you have native vegetation and a yard full of cactus snow all you really want to know is How do I get rid of the stuff?

For small areas of infestation a blast from the hose with a good nozzle on it should do the trick and you'll be giving your prickly pears some water at the same time. I've done it and it seems to work.

For those out of control areas, Arizona Cactus Sales in Phoenix recommends Malathion mixed to ornamental's application strength and mixed with a little liquid soap to act as a wetting agent to make sure it sticks to the insect long enough for them to perish. Repeat the process again at seven days and 14 days after the initial application.

According to Arizona Cactus Sales cochineal spreads between prickly pear by hitching a ride on bird's feet. Makes sense and remember to wipe your feet before entering your home because there's no telling what you're going to track inside. (1999)