help!!!

[spinessa]

IMG_20160925_170600.jpg (86.68 KiB) Viewed 1016 times

Hello, i'm a begginer in cacti growing.
I have a cactus with white powder on top.
Can someone help me and tell what is this and what I have to do?
Thank you!

[teo]

Mealybugs - see 'Pests & Disease' on this site

[greenknight]

Yep - assume all the plants around it are infested, too, the young mealybugs are very tiny crawlers.

[spinessa]

Thank you for the answer!
This cactus is also infected?

IMG_20160926_104246.jpg (57.2 KiB) Viewed 975 times

[teo]

Can't really tell from the picture. I guess the white stuff on the soil is perlite (and not a pest)?

[spinessa]

White stuff from the soil is perlite,you are right...but on the cactus?
Thank you!

[teo]

The white fluff on the (second) cactus is (probably) just wool which should be there.

[spinessa]

Ok,thanks a lot!
But on the first,if it is only white powder,no bugs,do I have to do something (to use insecticide)?

[teo]

In my experience: there is never just only the white powder (residue) - there are also bugs (which sometimes can be hard to find) so I would recommend a systemic insecticide.

[teo]

P.S. - after looking at the first image again and if there are no bugs on the plant to be found - maybe it was a false alarm and it's just normal cactus wool on the top.