What is growing on my Melocactus?

Trouble shoot problems you are having with your cactus.
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mikethecactusguy
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What is growing on my Melocactus?

Post by mikethecactusguy »

Help please in identifying what is causing this grey mess.
20200405_081728.jpg
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20200405_081737.jpg
20200405_081737.jpg (95.57 KiB) Viewed 6837 times
Mike The Cactus Guy
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Dodi Russell
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Re: What is growing on my Melocactus?

Post by Dodi Russell »

Spider web ???
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Re: What is growing on my Melocactus?

Post by mikethecactusguy »

Thanks Dodi
Some of it does look like a web but most of it looks like grey cotton.
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Steve Johnson
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Re: What is growing on my Melocactus?

Post by Steve Johnson »

Hi Mike,

Don't know if it has anything to do with the grey cotton stuff, but I noticed a spine mealybug on your Melo:
20200405_081728_02.jpg
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Start here...

https://cactiguide.com/cactipests/#mealybugs

…then follow up for additional info here:

http://www.cactiguide.com/forum/viewtop ... 24&t=42129

You may have seen my presentation before -- if so, now would be a good time to review the section describing short-term and long-term solutions dealing with all types of scale insect.
If you just want photos without all the blather, please visit my Flickr gallery.
My location: Los Angeles, CA (Zone 10b)
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mikethecactusguy
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Re: What is growing on my Melocactus?

Post by mikethecactusguy »

Hi Steve
Thanks for the observation. I found that white "thing " you noticed in the photo. It never moved. It was a piece of perlite.
I am going to take your advice and use a systemic on all my cactus .
right After this next set of rain storms, i'll water everything with some Bayer.
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Re: What is growing on my Melocactus?

Post by Sarraceniacrazy »

Looks like a spider mite infestation.
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7george
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Re: What is growing on my Melocactus?

Post by 7george »

Do you see any damage? Can be just some spider breeding on the top of that cactus.
If your cacti mess in your job just forget about the job.
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Dodi Russell
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Re: What is growing on my Melocactus?

Post by Dodi Russell »

Sarraceniacrazy wrote: Tue Apr 07, 2020 2:47 am Looks like a spider mite infestation.
Do spider mites build nest like that ?
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Re: What is growing on my Melocactus?

Post by Sarraceniacrazy »

Dodi Russell wrote: Thu Apr 09, 2020 5:04 am
Sarraceniacrazy wrote: Tue Apr 07, 2020 2:47 am Looks like a spider mite infestation.
Do spider mites build nest like that ?
Yes. Spider mites make webs like a spider.
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Re: What is growing on my Melocactus?

Post by Steve Johnson »

There are two types of pest mite that infest cacti -- red spider mites (RSM) and false spider mites, AKA flat mites. The climate Mike and I live in isn't conducive to RSM, although flat mites are a problem I've had to deal with for years. Flat mites don't spin webs, but RSM sure do. From Wikipedia, here's an example of what RSM infestation looks like with a bazillion of the little nasties crawling all over their webs:
Red_spider_mite_(Tetranychus_urticae).jpg
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Mike, I don't think the webs on your Melo are anything more than plain old spiders -- nothing to worry about.
If you just want photos without all the blather, please visit my Flickr gallery.
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Re: What is growing on my Melocactus?

Post by mikethecactusguy »

Thank you Steve
I applied some Isopropyl yesterday and I think it may have done some damage to the cephalium.
See what happens.
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Re: What is growing on my Melocactus?

Post by Sarraceniacrazy »

Yea, i dont know as much about cacti as Steve for sure. Heres a spider mite(Tetranychus urticae) web. One of the more common ones. Its what i first thought of when i saw your pic.
160930-216-Red-spider-mite-grape.jpg
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Plus it kind of looks like lots of lil bugs in the web.
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