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Tuesday, January 12, 2021

OH, NO! SCALE

 If there is one advantage to being short-sighted it is that as you grow older your close-up vision becomes even more acute bringing with it an added bonus. This makes you capable of reading the tiniest print, taking out splinters and spines from cactus and you can see when scale develops on one of your cactus. Albeit, a little late but not too late this time. Certainly worth getting out the fine paint brush and the bottle of 70% alcohol. 

How could this have happened? I am normally very observant when it comes to any kind of change. But this was the problem that I discovered this morning when I went into the greenhouse. It almost seemed that the multiplication of the insidious scale had happened overnight, although it had probably been going on for a while. I have scoured the Internet for an identification on the cigar shaped invaders. The only photo I came up with was Eunoymus scale. Yes, there are one or two of the adult tortoise-shell type scales but what are these others? Are they a different type of scale or the young? I think they maybe what are known as the crawlers which is a time at which the insect is most vulnerable. I spent about 30 minutes painting them with alcohol and finding that many of them just seemed to be easily removed by the treatment.I will repeat the application in a weeks time keeping them in isolation until clear.

This is not the first time scale has visited my cactus and succulent garden. Outdoors, the prickly pears ( Opuntia) also get scale, the kind that look like little tortoise shells or limpets. They also seem to appear overnight soon turning the whole pad white if you don't catch early and sucking the juices from the pads. When a pad becomes extremely infested it is simpler to remove rather than treat. So far no cochineal scale (Dactylopius spp) have visited my prickly pear This scale, in the adult stage, has the white fluffy coating that is hard to penetrate with oils and soapy sprays. If there is one reason for liking the cochineal scale it is because it carries with it a great story. When I give tours at the Wildflower Center I delight in finding the scale and telling people how it was discovered by the Spanish when they arrived in  Mexico and became so prized by them that its value was second only to silver.  I usually scrape off a scale with my finger and squash it to reveal this bright red color. The Aztecs used this carmine red to dye cloth producing vibrant red color. Europe had nothing like it and the Spanish were successful in keeping their source secret for many years. They managed to do this until 1777 when a French explorer discovered their secret source in Oaxaca.

When I first heard the story it jogged my memory of the little bottle of cochineal in the pantry at home which was used for dying cakes pink. At first I was a little horrified but then I learnt about the later substitutes for cochineal, which had almost killed the industry. Many of the artificial dyes that had been created were found to be carcinogenic. Today cochineal is used less but still found in candy and lipsticks although the cry from vegetarians has led to discovery of vegetable dyes being used. And yes, all those red Smarties I ate as a little girl and used to paint my lips were dyed with cochineal.

4 comments:

  1. I spent a number of years studying cochineal (and other insect dyes). The color (and bitter flavor I believe) of Campari also come from cochineal. It may be more widespread in food than realized, it has one of those letter and number combinations E120? E122? that disguises it in a number of places. I've never seen it growing, but hope to one day. I kept an eye out when I was in Santa Fe last year, but had no luck.

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  2. I heard the story about cochineal scale a year or so and was amazed. Nature presents very intriguing puzzles! I hope you manage to get the problem in the greenhouse quickly under control.

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  3. I remember when the Starbucks cochineal controversy hit the internet. Oh no!!! Insects in our treats! But as you point out that's much better then the dangerous chemical alternative.

    As for scale and mealy bugs they are a constant pest on my containerized plant. I keep fighting the battle. I hope you are successful!

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  4. Good luck! It sounds like you know how to deal with scale. I have a few methods that work for a while, too, and it seems like scale always hits my sunroom full of plants in the late spring. Grrr. Regarding eyesight, my farsightedness keeps getting worse, so I'm the opposite of you as I age: I can drive without glasses, but I MUST have readers on hand at all times because I can't read anything up close without them. LOL.

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