I'd still like to know where they come from. I realize you can pick them up from a plant shop on a new plant, but what if you don't get any new plants? For example, up here in Wisconsin, if I have a mealy bug free plant collection, and no new plants are introduced, can I still get mealy bugs from putting them outside?

Yes, indeedy. You can even get them inside on a previously problem-free collection. They are weird. I have no idea where they come from but it doesn't seem to matter whether you get new stuff or not. They just pop up sometimes.

I founda few on my mimosa silk tree yesterday, wiped them out thank God, but then proceeded to look over every single plant top to bottom. ....and if you're familiar with my collection, there's quite a few to go over. For whatever reason they were only on the mimosa silk tree I'm growing? ? But i couldn't be more happier that they weren't spread on my cacti an succulents. ...this is what i get for letting someone store there Mini tree on my Sun porch :-(

I agree.. the nasty buggers can just show up!

Sundewd, I hope you got it under control!

I think the wind blows them in...IMO
I have several plants that need to be treated now. Seems like the same ones that get them every year.
One hoya on my screen patio but not the others...?

I see an insect more like a leaf hopper in the second picture. Nothing stands out tl me in the first picture, but if you were serious in your description "saw me coming and ran ", it's not mealybugs. They are barely mobile.

First picture shows the webbing on the developing pad. Second picture shows the white bugger on the larger ugly pad. Afaik, that's a mealybug. I was being exaggerative about the running away part... I kinda poked at it so that may have been why. That cactus has been sick for a while and I have suspected some sort of infestation was killing it. But it seems to be okay as it has two developing flowers and new pads coming. This is the first time I have ever actually seen an actual pest on it. At any rate we got bombed by rain all night and it is due to continue over the rest of the week. I left my cacti uncovered to get a good watering since I havent done so in a while and to wash out any remaining mealies. They do not like water so its as good a defense as any.

This post was edited by Sundewd on Tue, May 27, 14 at 10:56

The white cotton gunk in the first pic definitely looks like a mealy infestation.

The white critter in the second is a leaf hopper nymph.

I looked through a bunch of pictures... I always thought the leaf hopper are green but apparently there are different types and that they do seen to also form webs. Hm, well, whatever it was... It's gone now. Hopefully it was just a leaf hopper.

Aaah, the mealy monsters. I've been in battle with them since April. Got all over my echinopsis. Yes, at the nymph stage, they are really tiny and easily airborne and WILL spread like wildfire unless you knock them out at this stage. I've been using alcohol 91% spray on the stem and leaf joints in the evenings. If the next day is going to be hot keep them out of sun for a few days after spraying.
Laura1, If you find the same plant is getting attacked every year and you haven't changed the mix, they're probably holed up in the pot and are cycling generations of bugs in there. Check the mix, edges of the inside of the pots, under the plant canopy and the roots to see if you have the pests present. To break the cycle, esp. at nymph stage, you just have to be diligent and consistent with applying insecticide every 5-14 days for a few months.

Can, also, try diatomaceous earth as a deterrent mixed in the potting mix. DM is a mechanical deterrent that can desiccate most insects when pierced with the dust. Apparently ants can bring the pests onboard as well, so they should be dealt with as well. I'm using boric acid.

Now, I always check any plant before it comes home.
Hope you eliminated the problem on your opuntia.

So it came back... But I squished the one present and sprayed a stronger mix on it again. I suspect the rain washed away my deterrent. However this thing did seem to be a leaf hopper... Because It hopped! Pretty far onto the porch. Which is how I squished it.