Grux -

you need to purchase Marathon and mix it with the soil.
The ones you definitely know are infested - I would cut the crowns off - dispose of the soil and roots - really clean the pots - boiling water with Clorax - let them sit - etc.

Try to wash these crowns - with Clorax and water - 1:4, rubbing alcohol/water - 1:4 - rinse them, recut and reroot in a baggie and in isolation.

Mealy bugs are very contagious - there is no guaranty they will not show up somewhere else. I would add a bit of Marathon in every pot and dig it into the soil - or just repot everything in a soil with 1 teaspoon of Marathon per gallon of soil - Fred will correct me if it too low - but it's what I use.

Next time - put new plants in another room and observe them for 3 months. Even the best and most reputable growers are not protected from bugs - so never-ever put the new acquired plants with old ones.

Paranoid you are not! The bugs are out there. Who said that your exotic $100 plants are free of them?

Good luck - and you will overcome!

Irina

hello irina and shiver, thanks for your responses. go figure that it is not my cheap grocery store AV that have the problem :-)

my concern is, what do you think the chances are that these bugs can travel down 6 inches of a pot, cross 6 inches of windowsill, up 6 inches of a pot onto a new plant? the plants are not touching each other.

i have this beautiful kei-yoki plant arriving in the next 2 days and will certainly make sure it far from the rest!

cheers, greg

Unfortunately, chances are good that they've already spread. Mealies don't spread quite as fast as say, spidermites, but they do get around. Sorry!

Even more sorry to hear it's your expensive plants that were the victims. :(

If possible (and if you have the room), isolate each plant in it's own window or under it's own light. That should at least slow the buggers down while you figure out which ones are infested. Maybe you'll get really lucky and they won't have spread, but it usually doesn't work out that way for me.

Hi,
I agree that mealies can spread from plant to plant very easily. Just make sure you wash your hands between touching infested plants and non infested plants. I too would reccommend using Marathon or Imacloprid for soil mealies, however I don't know if it is effective in cleaning up foliar mealies. If I find a presence of foliar mealies on a plant, I remove it immediately, strip the plant down to about 6 leaves and repot it. At that time if I see any foliar mealies left I attack them with a brush and alcohol. I make sure I check the plant daily to see if any more have sprung up. If so I continue to use alcohol on them and keep them in isolation for as long as it takes until I see no more evidence of mealies.
Fred in NJ

I can confirm that Marathon works on folair mealy bugs. My friend at work bought a gorgeous dieffenbachia to put in her office. In no time at all this thing was covered with white fluffies and it was looking sad. Looks like they spray them in greenhouses to control bugs - but not to eradicate - so when the spraying is over - the mealies hatch from eggs with vengeance.

We took the plant to the lunch room, washed it in the kitchen sink to remove whatever was crawling - and I put a teaspoon of Marathon on the soil and scraped it in. There were some on and off - but eventually they all disappeared.

Fred's approach takes much more time and patience - but it is not using any poison - and is significantly cheaper. Mine is in half gallon and cost me about $100. I bought it 4 years ago - and still working through the first half.

So - Greg - if you plan to keep a large enough collection - may be eventually you will need to get it. Fred just mentioned that you could get a smaller amount for less money - look back several threads.

Foliar mealies travel to lay their eggs somewhere else. And you can touch the plant or windowsill and accidentally relocate an egg or dozen.

The war against bugs is a part of life for the collector...

Irina

hello everyone, thank you for your kind responses. I have two more newibe questions about this - foliar and soil mealy bugs are 2 different kinds right? A plant can have one, or the other, or worse- both kinds on the plants at the same time?
Where or how can I get this "marathon" product in Canada?
thanks again.
greg

Greg -

yep - you can have all the bugs at the same time and mites too as well as mildew and crown rot. In this case I would chuck your collection, sorry.

Try to do the google search for imidacloprid. it is a generic name.

good luck

irina

I have a fairly extensive and nice succulent collection (mostly from leaves dropped on floors at plant suppliers! They grow fantastically well, and are free! ;) and, two plus years ago (this is 1/4/2014 today) I got a great price on and end-of-year sale orchid: 2 dollars. I checked it for MB's and put it in my "triage" (holding area) plant room, but it not only did NOT evince signs of MB's, it began to bloom incredibly beautifully. After 1 1/2 years in the Triage room, I brought it our to the kitchen where my succulent collection lives, and it bloomed even MORE. And, two months later... mealies. ALL over the bottoms of the orchid leaves, and in the nodes. I sprayed pure alcohol, on the leaves and nodes and put it back in triage. I have NO idea where the MB's came from, as the first time I saw them they were on the orchid, which was the only "new" plant I'd intro'd to the succulent collection in quite a while.
Alas, I saw that some succulents were getting infected and went on the attack: I put about one cup of alcohol in 3/4 gallon of water, in a deep, wide container and plunged the succulents into that for 12 plus hours. When they came out, I watered the soil with clear water so the roots were not sitting in alcohol (made THAT mistake once, and once was enough), and am also using Fred's method of alcohol directly on the nodal areas, scrubbing with a tiny "specimen" collection brush (I "swipe" some from my MD because they're perfect for this job) to get past the white, cottony nest and at the actual bug. I dip the brush in alcohol (poured into an at least 2 inch deep small bowl, to prevent spilling) and scrub as well as I can to get the tiny, flattish bugs. I hates 'em!

I pray both methods work and I can save my darling succulents. I do like them so!

After years of fighting Thrips, Mealybugs, and Mites, I have come to the point where I've concluded that, many times, the best thing to do is to toss affected plants as a safeguard for those that are not yet affected.

Many times, it's cheaper to simply replace suspect plants, rather than try to recover them.

But you might study up on recovery methods just in case you need to try and save an expensive or beloved plant.

You need to use a systemic insecticide. Check what is recommended for succulents. We use Marathon for gessies soil, you can use Merit for spraying but you need to check if these are not going to damage your cacti and what not.

Trying to nail them one by one with a q-tip - it's like trying to eradicate mosquitoes by slapping them. There is always more.

Hi. Old thread but I think it exaggerates how easily mealies spread. These quotes are from this Masters Thesis:

• "The first mealybug instars do not move very far by crawling and rarely reach an adjacent vine in this manner"
• "Of all the stages in mealybug development, first instars are the most mobile since mealybugs tend to settle as soon as they encounter dense areas of trichomes or cracks in the shoot of vines "
• "Thus, long distance (between-vine) dispersal is limited to wind dispersal (e.g. natural or spray induced air flows), and by contact by humans (pruners, gloves, spray equipment, etc.), or potentially other animals in the field."
• "A recent study on the grape mealybug (P. maritimus) by Grasswitz & James (2008) looked at movement of mealybugs over a three-year time span. During the three years, they found mealybugs are capable of walking on vines in the field up to 90 cm from their origin point of release; however, most were found walking considerably shorter distances."

So it seems to me the conclusion is that if you keep the plants 1.5 m apart then no mealy crawler will crawl between them (and with slighty less distances they might but not likely). And that what you have to worry about is wind/drafts and above all humans (and animals) who touch the plant.

I also read somewhere someone stating pesticides don't work fast enough compared to how fast mealies reproduce but I don't think that's the case, I think the limitation of e g neonicotinoids like Imidacloprid is that the systemic action isn't strong enough due to (A) not reaching sufficient concentration in general and (B) not reaching sufficient concentration at some part of the plants where the bugs are. One way to address that might be to increase concentration of solution, but Imidacloprid doesn't have very good water solubility, I suggest switching to a different neonicotinoid with better solubility of which Dinotefuran (sold as Safari) is by far the best.

Another thing to consider is that there are hundreds of different mealybugs of which some are more common and in tests some pesticides work best on some of these and some other on others which you can see here. As you can see, sometimes Safari has rating 5 and sometimes TriStar, even though both are neonicotionoids. Personally I wonder if this might have to do only with concentration, since all neonicotioids do have the same mode of action. But to be on the safe síde, maybe:

1. First spray with Imidacloprid or Thiacloprid (whichever is available in your country) and cover every square mm of visible sides of plant and both sides of leaves since it also has contact action which is faster than the systemic activity (and this spray is easy to find, and will buy you time to find Safari, and limit amount of crawlers around meanwhile),
2. 1-2 weeks later treat with Safari drench (possibly overdose),
3. 10-14 days later leach the soil (using clean water, 2-3 pot volumes) then add fertilizer sticks with Acetamiprid (easy to find).

Instead or in addition to "3" you might want to try Pyrifluquinazon spray (sold as Rycar) and/or Spirotetramat drench (sold as Kontos). Kontos, Rycar and Safari are not available except to professionals but you can find it by googling. If you need to repeat treatment, you should use a pesticide with a different mode of action like Rycar or Kontos. Kontos works very well on some mealies according to this (p59).

If you have experience that contradicts this then please let us now.

I can at least compare to spidermites based on experience: Above someone said that mites spread even more than mealies, but I have seen more than once how even a few millimeters between plant branches keeps them from spreading to the next plant (at least if the infected leaf is not above the other one).

Good luck.