from the furrows on the leaves, it looks like you might have problems with the roots that are weakening the plant and making it prone to infestation.

How many times have you sprayed them, and for how long? Yor post left me with the impression that you've only sprayed once or twice. If you haven't done so, you really should be spraying about once a week for a few weeks. A single shot won't do it, even for a systemic like bayer. When I say bayer really worked for me, it was after multiple applications. If you've used it multiple times, it's time to step up to a different pesticide. We in my industry use Safari for mealy and scale. I'd have to research availability and pricing for hobby quantities but it works well. Active ingredient is Dinotefuran.

Put rubbing alcohol on a Q-tip and touch the mealy bug. It may turn pink and disolve. Scrape away.

In my experience with African violets, this works very well.

With a huge infestation, which you don't seem to have, you could spray rubbing alcohol to disolve the mealies. Be sure to rince the plant with warm running water so the alcohol does not dry it out.

Nancy

Two questions:

1) smwboxer: you said I may have issues with the roots. Can you explain? Do you mean issues with the roots because of the mealybugs or issues with the roots in general? This plant started to look frail awhile back and when I repotted it I noticed it had very few roots. I dipped it in rooting hormone when I repotted and it seems to be growing some new roots now.

2) continuing treatment: I've only sprayed once. I thought I had really sprayed well. I will spray more frequently now I guess whenever i see them. But what should I be spraying more frequently? Just the leaves? the roots? everything? Just where I see mealys?

Might mealys be living below the surface in thie potting medium too? Do I need to pull the potting medium apart and investigate for the bugs? or do they only stay above the surface?

all of your help is greatly appreciated. This is my first time dealing with mealys and feel kind of lost.

I should also mention that I'm using the Bayer Advanced that is in the blue spray bottle. I think it also comes in a larger bottle that you dilute with water. Perhaps I should get this instead and fill up a bucket and start to dunk all my plants, pot and all inside?

terpguy, I am trying to understand your strategy. Like you, I used multiple applications of "a systemic like bayer" (imidacloprid).

You continued that Safari -- Dinoterfuran is a good choice to follow imidacloprid. I don't understand this selection.

Both products are nitroguanidine deriviatives. Would a pesticide from a completely different source be more effective as part of a broad spectrum plan? If the answer is yes, what would be a better "class" to use next?

I have imidacloprid on my shelves ready for early spring. I also want to stock another effective product which will hopefully keep the harmful insect population off-balance. I don't want to encourage resistance to any product or "class" of products.

Thanks for your thoughts.

--Stitz--

I've observed mealy bugs sucking off roots of mounted plants - not sure if this is indicative that they actually reside inside potting media. Like aphids, these suckers can give birth to live young as well as lay eggs. Typically all insecticidal treatments need to be repeated every 2 weeks, even if you do manage to cover everything. This is simply because even if you are thorough, some eggs may survive, so you need to keep going at it until they are all gone. Just checked on google, and it seems like eggs take about 10 days to hatch...so if you spray every 12 days or so, you should kill everything.

I would spray everything above the potting medium and soak the medium as well. I'm not sure about this product but I've done this with safers end all and the plant was not harmed.

My first asumption would be that the roots have died due to being kept to damp. You can tell by the leave that the plant is no longer taking up water like it should.

Stitz, its based on my experience. Didn't know they were that closely related, and you are correct that a different family would be best advised. However, I've been using Merit and Safari in any combination of side by side and one after another through the years at work and my experience over the years has been where one fails, the other succeeds...every time without fail.

addendum:

Merit is one of the brand names whose active ingredients is imadicloprid, for those who don't know. As far as class, stitz, hell if I know. I am only vaguely familiar with the concept of different pesticide families. By your reply, you've demonstrated that you know more than I do! I rarely have pest problems, so rotation and pesticide classes, for the time being, is not a concern in my collection. I can recommend Talstar, which is a pyrethroid (a different class!). But I know for a fact that its pretty expensive. $50 for a pint on one site I found.

Also, yes mealy can live in the potting medium. Its a constant problem for us interior landscapers. If anyone has a plant service at work, and they use spanish moss, the mealy can live in that moss too. As well as the carpet. Its such an insidious beast! Repotting helps, and I'd also consider granular or drench pesticides that are applied to the soil.

Keep touching every one you see with a cotton swab dipped in alcohol. Spray the leaves and spray the medium heavily with the Bayer Advanced once a week for three straight weeks. After that, spray the plants with 50% alcohol and 50% water. Some infestations are insideous! But keep at it, eventually you'll win.

There is a particular type of mealy bug called a "Root Mealy Bug" and it does live and breed in the root mass. See link below. I know malathion has a really bad reputation as a pesticide, but it does work on these critters very well. I haven't had a sign of a mealy in a couple of years.

Kevin

Here is a link that might be useful: Mealy

Pour the Bayer through the media, it is systemic and can be taken up through the roots. Repeat treatments are a must.

I see baby mealies leaving the mother - yuck!

Brooke

Fabulous fact: baby mealies can be spread through the air as well, though it not nearly as common as the usual vector methods. They are very light weight and, especially if there's big masses of mealy, josteling the infected foliage during handling or fast air movement can dislodge them. As a previous poster noted, they really can be insidious!

I have been fighting scale which invaded my greenhouse for about 3-1/2 months now. Tried many things, including the Bayer Advanced systemic spray. I think I may have lost one or two plants, but am on the way to recovery.

It is my opinion that since this is a systemic product, and the OP has completely repotted all plants, repotting should not be necessary. I would advise removing the visible offenders with alcohol swabs in conjunction with at least a 3-week systemic spray treatment on all leaf surfaces.

Regarding the pictures, these leaves are very stressed. I have had some success with wrapping phal leaves with wet paper towels, re-wetting by misting the towels heavily a few times a day. It may not work, but is worth a try. Since you have critters, be sure to destroy the paper towels afterwards.
Ann

terpguy,

What are the usual vector methods for Md mealybugs? Thanks.

--Stitz--

Stitz, infected tools and infected hands, 98% of the time. I always use Purell after I handle an infected plant. But they are completely capable of crawling around benches and carpets and simply walk their way to a neighboring plant (as far as I know, the only one that can do that). Plus airborne mealy babies as well. If you're in an office--keeping in mind this is a rarity and not frequent--airborne mealy can get into the ventilation system and affect another plant in another room. Again, thats incredibly rare, but it can happen. Same with fungus gnats, but its incredibly common for them since they are capable of breeding in the condensation in the ventilation system.

It sounds like the ventilation system is a health hazard since fungus gnats can't breed in water. YUCK!

Brooke

I wouldn't think so since is so common. If that were true you would think we'd have a lot more mold issues than we currenty hear about. Tiny little 6" pots have enough fungi to maintain hundreds of larvae. It doesn't take much at all to sustain them.

Earlier, the word "vector" was used in this thread. I think that the word "vector" is intended to describe disease transmission. Definitions of useful words:

vector -- an organism (as an insect, etc) that transmits a pathogen
pathogen -- a specific causative agent (as a bacterium or virus) of disease

--Stitz--

Rest assured my use of the term of vector was appropriated just fine as it is frequently used in my industry to include the transmittal of small pests. You are introducing a plant killing organism, after all. Technically, yes you are correct. But it can be appropriated in broader terms.

Humans are included, btw:
Definition found online:
any agent (person or animal or microorganism) that carries and transmits a disease

I agree. Vector was the appropriate choice regarding the "infected hands"; fomite is the choice to describe the "infected tools". Fomite is associated with inanimate objects.

--Stitz--

I use Merit (I believe it is Merit 75) as a drench. I drench the medium once a week for about five or six weeks. I don't do any top spraying at all.

After the second into the third week the mealys begin to die. It takes the plant a week or two for absorbing the Merit and circulating it.

Length of application is important as mealys are travelers. They will be roaming about everywhere and you have to make sure that you get the ones who eventually 'settle down' for a meal.