Is this a problem or natural growth?

[WayneByerly]

When I first bought this cactus, it looked like this:

1.jpg (48.73 KiB) Viewed 1057 times

but in the last few months, the top of it has begun to look ... well, chewed. There's nobody else who lives with me and my succulents ... except maybe the bugs that one cannot entirely remove from ones life.

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and in recent weeks, it has begun to look as though a thin mixture of muddy water has been sprayed on it and let dry.

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and the poor thing has had these black "exudations" since SOON after I first got it last summer (Jul/2013)/

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My questions are:
1) What the dickens IS this? Is it a problem, or is it normal growth? I know SOME cacti look a little scruffy.
2) IF ... if it is a problem, should I just go ahead and discard the cactus so that whatever it has got does not spread to anybody else?
3) IF ... if it is a problem, is there a cheap easy fix? I mean, the cactus was only about $2.00 ... if it has a PROBLEM, it might be cheaper just to throw it away and replace it.

I'll assign my firstborn child to the first poor soul that responds to this (careful, she's got an 18 year old son and CONTINUES to be a disappointing problem to the rest of her family).

[greenknight]

Could be mite damage. Definitely quarantine it. If you want a cheap fix, insecticidal soap does work on mites, so does rubbing alcohol; chemical miticides are not so cheap.

See: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html" onclick="window.open(this.href);return false;

Also check out the "Pests and Diseases" link at the top of this page.

[WayneByerly]

insecticidal soap does work on mites, so does rubbing alcohol.

what about "Denatured Alcohol"? is that the same chemical compound but without the water?

Also, I've got some "Safer Brand Insect Killing Soap with seaweed extract" ... is this the kind of insecticidal soap you are talking about?

BTW ... you are the lucky winner of my firstborn child prize. send me your address ... i'll fold her up, put her in a box and mail her to you ... GOOD LUCK!!!

[WayneByerly]

Also check out the "Pests and Diseases" link at the top of this page.

I THOUGHT that I was IN the "Pests and Diseases" section of the forum ???

[CactusFanDan]

what about "Denatured Alcohol"? is that the same chemical compound but without the water?

Alcohol with denatonium added to it so people don't drink it.

Certainly mite damage. Mites are hard to get rid of, but I've heard good things about using tetrasan to get rid of them.

[Steve Johnson]

Certainly mite damage. Mites are hard to get rid of, but I've heard good things about using tetrasan to get rid of them.

I concur with Dan's diagnosis, and as a recent convert to TetraSan I would highly recommend it over everything else. The following data sheet from Valent BioSciences discusses spider mite control only for non-xeric plants, but this applies to cacti and succulents as well:

http://www.valent.com/professional/prod ... geid=74005" onclick="window.open(this.href);return false;

While TetraSan is expensive, IMO it's worth the price of admission -- a little bit goes a long way, so unless one is on a really tight budget, don't be put off by the initial cost given how much TetraSan will do to keep your plants mite-free over the long term. You can find it on eBay here:

http://www.ebay.com/sch/i.html?_trksid= ... n&_sacat=0" onclick="window.open(this.href);return false;

Wayne, there's no doubt about the fact that your cactus got hit by a really bad infestation, and the mite damage is permanent. I don't know the species you have there, but if it's a plant that can be easily replaced, you may just want to get rid of the poor thing and try again with a new one. If you take me up on the TetraSan recommendation, start using it immediately as a preventative measure. You shouldn't need to do this more than twice a year. I'm also concerned about the black lesions you were telling us about. Since you said that they appeared soon after you got the cactus, I'd immediately suspect rough handling by the seller. Those lesions would be consistent with the plant being poked by the spines of another cactus. (Maybe more than one that did the poking?) Penetration of the skin is asking for localized fungal infections that could spread over time. If the lesions haven't calloused by now, a climate prone to high humidity could be complicating the situation for you. If you decide to replace your "problem child", I'd highly recommend going to a nursery that takes better care of their cacti.

Also check out the "Pests and Diseases" link at the top of this page.

I THOUGHT that I was IN the "Pests and Diseases" section of the forum ???

I have a feeling greenknight misspoke -- there's a page on the CactiGuide website dedicated to pests and diseases here.

[greenknight]

In the green bar at the top of the page, there is a link to that page - I should have been more specific.