since its on every single point.. one would suspect its natural ....

bugs are not that efficient in spacing themselves .. lol ..

if you notice.. there is a pattern to it ... not the oldest outer spikes .. and not on the youngest ... lol.. that should tell you something.. but i dont know what.. lol ...

i mention the pattern.. for you to relax ... even if you dont know.. the pattern should suggest its normal ... abnormalities usually dont do patterns ...

ken

Recently bought & repotted. I take it you didn't notice this when repotting? If not, it may be mealy bugs or scale.

tj

I've been searching on the Internet a bit, and if this is a barrel cactus, then apparently having some wool/fuzz on the top of the plant is normal. So perhaps I'm mistaken on thinking that it is mold or mealybugs.

Normal fuzz!

Mealies move...

When you repotted this cactus did you use regualr potting soil or one designed for cacti?
Could this soil be too wet for this cactus?

C'mon, peeps! This is perfectly normal! You need to compare images of similar cacti.

Tracy, you should consider not using gravel for your cactus (or other plants). In the bottom of the pot, a layer of gravel actually brings the moisture level UP into the roots and slows the evacuation of water. Rather than 'improving drainage', it impedes it. Also the layer of gravel at the top slows down the evaporation of moisture from the surface of the soil. I know that it looks pretty cool but that gravel isn't doing your plant any favors.

Cacti need to be really drenched every once in a while so that they can get water in all of their storage cells. That's a lot of water! BUT we want all of the excess to be able to drain away or evaporate. Then you wait and wait and wait until the next watering.

first thing i said, rhiz..

ken

I know, ken. :-)

Thanks for your help everyone, especially rhizo_1! (I've followed your advice and taken the rocks out of the top and bottom of the pot.)