Dealing with orchid pests on a broader scale

[ArronOB]

Hi. I’m wondering if there is a cheap and environmentally safe way to deal with big old orchid plants growing outdoors.

A bit of background.

I have a collection of orchids growing in a small shade house and I fuss over them in the same way as most of us here. When they get scale (common) or mealy bugs (rare) I go over them with a cotton bud dipped in alcohol.

I also have a number of big, old orchids growing in baskets hanging year-round in the back yard. These are mostly hardy species like Laelia anceps, Stanhopeas, Coelongynae and a few Oncidium types. There are also bromeliads. They get almost no care and both the orchids and broms have a lot of scale, which doesn’t seem to slow them down any so it’s never really worried me. Now I’m thinking they may be acting as a reservoir for reinfestation of the cherished ones in the shadehouse somehow.

So is there a way to treat the big, old plants which is cost effective and not too time consuming.I don’t mind if a bit of damage is done (they’ll recover). I don’t want to use a Neonicotinoid outside, and anyway our local shops don’t seem to stock them now.

I use a product called ‘Eco-oil’ on our fruit trees for sap-sucking pest species. It’s this Multicrop 3L EcoPest Oil | Bunnings Warehouse. Should I use that on the outdoor orchids ??

Thanks
Arron

[Subrosa]

I personally like to use soap and alcohol. I use the soap to wash my hands after spraying something that actually works, and the alcohol to celebrate my victory.

[Dollythehun]

I was going to suggest horticultural oil. Since these aren't your "cherished" plants, why not make one a test plant?

[Ray]

I am not a fan of oils - it's too easy to burn the plants - and if I recall correctly (very suspect), bromeliads and oils don't play nice together.

My go-to in such a situation is acephate mixed with an insect growth regulator like kinoprene.

[ArronOB]

Originally Posted by Dollythehun

I was going to suggest horticultural oil. Since these aren't your "cherished" plants, why not make one a test plant?

Good idea. I’ll spray an orchid and a brom with the oil tomorrow.

[Subrosa]

Originally Posted by Ray

I am not a fan of oils - it's too easy to burn the plants - and if I recall correctly (very suspect), bromeliads and oils don't play nice together.

My go-to in such a situation is acephate mixed with an insect growth regulator like kinoprene.

Followed by washing your hands with soap and a drink in celebration?

[ArronOB]

Originally Posted by Subrosa

Followed by washing your hands with soap and a drink in celebration?

Ok, so today I picked out an old and valueless bromeliad and a dilapidated Laelia anceps and sprayed them with the ‘Eco Pest Oil’.

I picked out another old anceps and drenched it with ‘Fruit tree and Citrus Oil’, which appears to be the same thing despite the name.

It will be interesting to see what happens, and I’ll try to remember to post the results here in 1 month and then in 3 months time.

Now I’m off to have the mandated celebratory drink.

Cheers
Arron

[Roberta]

A thought on "contact" treatments such as oils... they kill the adults that they encounter, may or may not affect larvae, but certainly don't do much to eggs. So I suspect that you will need to repeat the treatment in a week or so, and then a week after that. If you don't kill several generations (and so greatly reduce the reproductive population) they'll just come back.

[pikastu]

Having recently purchased some predator bugs, I couldn't recommend anything better!!

I've had decent success with pyrethrin, soapy water, alcohol and neem oil (neem seemed to work the best out of all of them), but the scale, mealy bugs and aphids kept coming back.

I released ladybirds and lacewings in the apartment, and a month later I can't find a single pest insect. I bought them from Bugs For Bugs up in QLD.

Not sure how they would work outside, but if there's enough food for them, I would think they would stick around? The supplier seems to cater towards large outdoor farms and crops etc so I guess it could work.

Also, if you do use oils, make sure you do it in the evening or on a cool day - I lost a few orchids after ignoring the instructions and spraying on a hot day.

[aliceinwl]

I don't know how it would stack up against the oils, but I've had good luck with a product marketed as an organic insecticidal soap. It does take repeated applications. I had mild flower damage on my Dendrobium nobile and some minor leaf damage on an Oncidium.