Bayer 3-in-1 now with NO imidacloprid
 

Hello,
I have a massive scale infestation among all of my cattleyas. In trying to control it, I sprayed the plants with isopropyl alcohol, Bonide horticultural oil, and finally, I had to replace the potting medium in most of my orchids. Still the scales are there.
I think I need to treat the plants with insecticide. There are a lot of mentions of using Bayer 3-in1 with Imidacloprid on the orchidboard.com forums.
The current Bayer 3-in-1 Insect, Disease & Mite no longer contains Imidacloprid. It is not allowed in some states (bad for honey bees).
Has anyone used the new Bayer 3-in-1 to control infestations? Could another product work just as well?
Thanks,

I haven't tried it but I will have to take a look. Let us know if it works. If it is meant for roses, it probably is very effective. Roses are very prone to all sorts of issues.

I have used the product, and it works very well on soft-bodied insects like mealy bugs and even beetles with shells, but scales are not listed on the label "kill list", probably due to the elimination of the imidacloprid.

You need to get rid of the scale urgently. What you see on the leaves is just the tip of the iceberg. Take the plants out of the pots and you will see ruin there. See how you look for something that destroys scales and changes the media.

I forgot to mention that acephate (AKA Orthene) has been my "go-to" systemic insecticide for scale for decades.

Scales are one of the hardest pests to get rid of. You have a very short window of time (the crawler stage) to effect them. Once they have formed the shell (the scale), they are pretty much immune to sprays and drenches. You need to identify which scale you have. Learn the life cycle. Then you can choose an appropriate pesticide to use. A systemic pesticide will give you a longer window of opportunity and your best chance to effect them. Many systemics take 2-3 weeks to be moved through the plant and be effective.
Orethene (acephate) is labelled for scale but you still have to hit that crawler stage. It also has quite an oder, use in a well ventilated area. Imidacloprid comes in many different insecticides besides ‘old’ Bayer 3 in 1. Many different names and concentrations from 1%-75% imidacloprid. The horticultural oils, are once again, for that crawler stage. When the oil can cover and smother them.
You can also use you finger nail or something similar to scratch them off individually. Then use a pesticide to control the next generation.
Do some research on what you have and you should have a good outcome. Best of luck against these pest

Toothbrush with alcohol. It's tedious but the most effective solution I have found. Make sure to scrub right down into and through the "paper" sheath covering where they usually get started.
Once you have done that, periodic use of horticultural soaps, neem oil or Orthene will catch the newbies before they "shell up".

I had scales (black ones) on some of my orchids. Instead of going to the shop and try to find something, I used Chaindrite that I already had. It is mainly used for killing termites or to prevent them by soaking the ground before building a house..
I sprayed the infested orchids one time and one month later there was not one single scale alive, only yellow spots on the leaves where they had been. There are no visible damages on the orchids from the insecticide.
The active substance is Bifenthrin, which is not restricted in US.