Mealy bugs?

[Roberta]

One thing to consider with systemics... orchids don't incorporate them very efficiently since they grow so slowly (and leaves are mostly pretty impervious). When you use something like Bayer's Advanced (imadacloprid) or Orthene, most of the effect will be from contact. Which means that you need to spray every 5-7 days for 3 or 4 weeks to get successive generations of the pest. (And better if the successive sprayings are not the same pesticide... rotating them reduces buildup of resistance) If the plant is in its growth period, you may get some residual effect at least in the new growth, but contact is important for nailing them NOW.

[malteseproverb]

That's interesting Roberta, I've never heard that before. I'm alternating between a systemic and just a contact killer (Bayer 3-in-1 and Talstar). Should I be rotating between two systemics instead? I've had luck with my current system in killing off a pretty intense scale infestation, and so far I've only found one mealybug on one plant (and I've been looking). Are mealybugs significantly worse than scale? And do you think soaking the roots or the whole plant is therefore a better method of getting the orchid to take up the systemic?

[Roberta]

I think that your scheme of the two pesticides is fine. The Bayer also works by contact as well as any systemic effect. Scale is a lot tougher than mealies... if you kill the mealy bugs even with alcohol and stay on top if them if they re-appear, you'll keep them under control. (I think that Phalaenosis is Latin for "mealy bug magnet...) Sounds to me like you have it well in hand.

I don't think the extra soaking will be useful for taking up the systemic. It just doesn't get transferred to the surface tissues all that efficiently. It certainly helps longer term (because there will always be new ones in the environment) but sounds like you have gotten them now, and that's great.

[Leafmite]

Phals do seem to be the orchid magnets for mealy bugs. Good luck with your eradication of them.

[bil]

My fave systemic is Imacloporid, but that is a contact too, and I would have thought that was true of all systemics.

I was spraying the gazinias against some beetles that were destroying them, and one flew off as I started spraying. I swung the nozzle and he went thru the spray. He made it halfway across the garden, then fell out of the air like a stone.

[Arizona Jeanie]

Seems to me that since mealy bugs are sucking insects, the most effective way to get rid of them is to get a systemic insecticide into the plant instead of on top of the bug. I've heard that orchid leaves don't absorb much, so I think I would be inclined to soak the whole plant, particularly the roots, in a basin or bucket. But then I only have a few orchids and haven't had a lot of problems with insects, so that's why I'm asking about it. I'm generally opposed to excessive use of chemicals, especially if they don't work, and one way or another they will end up in our environment. It sounds like these chemicals must have quite a bit of contact efficacy, I'm glad to hear they seem to be working well. I'm more familiar with other types of plants, (systemics need to be taken up by the plant, either through foliar or root contact). I'm happy to be learning tips and tricks from the orchid experts here, thank you all for the information!

[Roberta]

I just don't think that soaking the whole plant will accomplish any more on the "systemic" side than spraying. If it doesn't reach the surface tissues of the orchid (which is where the sucking happens) that aspect of its action isn't going to happen. (Mealies and scale and aphids don't typically get to the deeper tissues that might have incorporated the pesticides from a soaking) On the other hand, that tough cuticle on the leaves and pseudobulbs tends to protect the plant - so that if a surface infestation is controlled, the the damage from the little bastards is minimized.

[flowerpower]

I saw a youtuber battle with mealy bugs. She kept spraying but the plant deteriorated. She unpotted it and found their nest in the media below the crown (it was a phal).

I had mites once. No spray helped so I unpotted them and dunked them all in soapy water. It worked well but I would only try it on a hardy orchid.