So what's a reasonable quarantine period for new plants?
 

I'd always thought a couple of weeks would be sufficient, but I got a real surprise last night. I had purchased about a dozen new plants (orchids and other epiphytes) for my new living wall. I had these newcomers sitting in their own plastic bags for two weeks before I placed them on the wall, and added about as many plants from my own collection. And they've been happily co-existing for about 3 weeks. Here's a photo, the wall was displayed at the Green Living Show at the end of April:

http://www.orchidboard.com/community...iving-wall.jpg

Last night, I looked very closely at my variegated hoya (lower right quadrant) because I thought it was sprouting a bunch of new growths. Instead, I saw big, fat, fuzzy mealy bugs gathered at the leaf nodes. So that's over 5 weeks from the date of purchase, and I've never had mealies on my plants.

Needless to say, I squished as many as I could find and sprayed the plant and its neighbours with SucraShield very thoroughly. But I'm still puzzled by the amount of time that it took for the infestation to show up. Do I really need to quarantine each new plant for 6 weeks?

Maybe the mealies got on your plants when they were at the show in April?

6 to 8 is what I've seen. I believe the mealybug life cycle is 8 weeks, but I'm not sure. I can tell you that it takes 30 days for an egg to hatch and mature into an adult mealybug.

No, the living wall didn't come in contact with any other plants at the show, and people weren't really touching the plants.

The 6-8 week cycle for mealybugs is astounding. I guess I'll be doing weekly sprayings for a while. RG, do you spray your new arrivals as a precaution? I think I'll start doing that, for the first 8 weeks at least.

No, I isolate them in my dining room for two months, which is getting on my hubby's nerves, because I always seem to have orchids on the table in there.... it's not like I buy orchids ALL the time.. just about... every two months or so. :D :D :D

I inspect my plants closely. I have found mealies on two plants. I repotted them in bark that I had soaked overnight, then sprayed with a light misting of bayer rose and flower. Tossed the old medium and the old plastic pots in the garbage, soaked the ceramic pots I put them in in bleach water and I sprayed the plants liberally with bayer rose and flower for three applications as advised on the bottle. No sign of mealies since. I only saw two bugs so I'm thinking they were hitch hikers from a pot or from the orchid show and got lucky that I didn't have to deal with an infestation.

For me, it depends on the vendor. With the vendors that I trust, I isolate the new orchids and plants for a few weeks. For orchids and plants I receive from other sources, I tend to keep them isolated for about three or four months. If they are thriving and don't have any suspicious marks after three or four months, I put them with the rest of the plant collection. If they don't thrive after that period of time, I keep them isolated due to the chance that they might be virused. I have no regrets about keeping them isolated that long. I just pitched one that really gave me a strong indication of possible virus.

I always do a preventative spray to new plants regardless of where I got them. I then watch them for several weeks.

Mealies can travel on a breeze, through window screens and probably on peoples clothes.

Brooke

It is absolutely possible those came in via sources other than your new plants. I'll second what Brooke said...they can get in through an open window or door and get to your plants.

I have been insect free all winter...nothing...not one little bugger to be found anywhere in my collection. Nothing. That was until this week! The other day I found a little mealy factory on a plant (and the little buggers had already spread to a couple other plants) AND early evidence of spider mites. I am religious about checking for things and none of these insects were here a week ago. 'Tis the season. [sigh]

Sorry to hear about mealy bugs, my like is for yours new living wall.

Thank you! I'll do a separate post about it.

In the meantime, I'm examining my orchids a lot more closely. With the warmer weather, we now have fungus gnats and ants, so I guess the mealies just tagged along.

I buy my plants from very reputable nurseries (these ones came from Humber), so I'd be surprised if they were buggy from the source. I guess anyone can miss a few eggs.