Thrips

[southernbelle]

This is an excellent article from Anthura which produces mostly mini phals (in orchids). It refers to thrips in phals, but the streaky damage shown in the photo is what I experienced in Phrags that was mistaken for spider mites (even by professionals). The areas on the leaves that are more widespread, I’ve seen on Paphs, and can easily be mistaken for high light damage or mite damage. The larvae are pretty impossible to see (even with 40x in my experience), but the adults I had were black and noticeable at that size with 10x. Not the same thrips I’ve experienced on roses which are visible to the naked eye.

http://anthura-unlimited.anthura.nl/anthurinfo-2021-februari-uk/thrips-phalaenopsis/

 

[musa]

Fortunately Thrips seem to be highly specialised. I had a severe infestation on most of my Amorphophallus, but some others stayed untouched. I was lucky they didn't like my Paphs either, some of which had direct leaf contact with infestated plants but stayed unharmed.

 

[southernbelle]

Fortunately Thrips seem to be highly specialised. I had a severe infestation on most of my Amorphophallus, but some others stayed untouched. I was lucky they didn't like my Paphs either, some of which had direct leaf contact with infestated plants but stayed unharmed.

Interesting, I’ve had them on cattleyas, Phrags, less on Paphs and phals all at the same time. I was treating for mites, mistakenly, which was not a frequent enough spray interval even though the chemical worked.

 

[musa]

Maybe I had a different species/type of thrips because they only went for the thinleaved Amorphophallus and not for titanum or glossophyllus or my Paphs. which have lethery leaves. Never thought of but it seems naturally that there are different species of thrips. I just hope that treatment works on them all...

 

[southernbelle]

Yes, the article goes into that and what the different species are. The main difference in treatment is how quick their life cycle is which is very important in knowing how often to treat.

 

[richgarrison]

thanx for that article ... i had previously thought a 2 week cycle for spraying was sufficient but then found a source talking a 1 week cycle... and now this... very interesting... and probably why it's taken quite the long time to see evidence of any success....

 

[southernbelle]

Rich, I find it very difficult because their life cycle depends on the temperature. Warmer very quickly, cooler a bit slower. I hate spraying because I have an indoor grow room, which means moving ALL the plants outside when weather permits or using a respirator and doing it in my sink. Really a pain...

 

[Ray]

You might consider Azamax. It's odor is not particularly pungent, and it goes away quickly as the stuff dries.

It's labeled for thrips, among many other insects, and has several modes of action to help eradicate the *******s.

 

[musa]

I just read the whole article, most enlightening. The thrips identification poster is great!

 

[richgarrison]

You might consider Azamax. It's odor is not particularly pungent, and it goes away quickly as the stuff dries.

It's labeled for thrips, among many other insects, and has several modes of action to help eradicate the *******s.

i've included that in my rotation (based on your recommendation) along with pylon, and abamectin... i had started with using the azamax in a drench it's just crazy expense as an application that way (i need 40+ gal to treat my slippers)...

 

[terryros]

Deb, I don’t think you summer anything outside, so I am assuming that thrips had to have come in on some plants that you purchased?

 

[southernbelle]

Terry, you are right, nothing goes outside in summer. The problem was most evident spring/summer a year ago when I lost almost all of my cattleya blossoms for that bloom cycle... Discouraging, to say the least. Funny thing is, the only plants I know they came in on were phrags purchased from a somewhat local grower. The grower said the leaf damage was spider mites that had been treated, so when they surfaced again, I treated for mites as they were too tiny to see even with 40x magnification. Only problem was that that spray interval for mites was about weekly, which was not often enough for the life cycle of the thrips (even though the chemical was effective for thrips, too). Finally I had one black adult I could see and knew, then, what I was dealing with.
I grew roses for years and was used to spider mites (two-spotted) and thrips (flesh colored adults), both of which were visible to the naked eye (with good vision), but certainly under 10x. These buggers are a whole different class, size-wize. Sometimes I have to wipe the area with an alcohol swab or paper towel and then look at the swab. Because of the alcohol they will be squirming, so identifiable, but it takes 20-40 power to see them. UGH!!! I've been dealing with this like a tension to be managed rather than a problem to be solved, and it came back to bite me again this winter, albeit not nearly as bad and I lost no blossoms to it. This spring I will pull out all the stops... I'm declaring WAR!!

 

[terryros]

I had better read the article to get more familiar.

 

[southernbelle]

I was impressed with the article. The photos are very helpful. I had one mini phal from Anthura and when I researched it’s origin, learned about them and get their newsletters. On the scale that they produce they’ve dealt with everything.

 

[kitfox]

I am preparing to use the nuclear option for these. I have used orthene for scale before, and never had any adverse impact on my orchids, but never tried on Phrags. Has anyone used on Phrags and was there any issue? Also a Paph rothschildianum... I hate this stuff, but I like the idea of a systemic to stop thrips dead.

 

[musa]

Unfortunately orthene (acephate) is not availale in Europe...

 

[southernbelle]

Unfortunately, even though very effective, if it splashes in your eyes, it causes blindness. I know of a dog that rolled in the grass where there was overspray (apparently attracted by the odor) and lost his sight. We always wore protective glasses, etc., when using to spray roses and only early morning when winds were calm.

 

[Ray]

I am preparing to use the nuclear option for these. I have used orthene for scale before, and never had any adverse impact on my orchids, but never tried on Phrags. Has anyone used on Phrags and was there any issue? Also a Paph rothschildianum... I hate this stuff, but I like the idea of a systemic to stop thrips dead.

Acephate has been my “go-to big gun” for decades. I have never seen a bit of harm to any plant, and most of my collection is paphs and phrags.

Just be sure to be thorough in your application regimen. I use and carry “Acephate 97UP”(97% active, made by United Phosphorus) and they recommend two treatments, ten days apart, but I have always used it three times at one-week intervals. Just be sure to wet the entire exposed parts of the plants and drench the medium each time.

 

[musa]

Has anybody already tried predatory mites on Thrips? Like Amblyseius swirski and Hypoaspis miles?

 

[southernbelle]

You might consider Azamax. It's odor is not particularly pungent, and it goes away quickly as the stuff dries.

It's labeled for thrips, among many other insects, and has several modes of action to help eradicate the *******s.

Ray, I'm looking at both Azamax and Talstar. Both say they cover thrips, scale, mealy bugs, mites and fungus gnats which is everything I've ever seen on my orchids. Azamax is more natural, but other than that, they both seem to be systemic. Would you suggest one over the other? I grow indoors and sometimes want to spray a single plant in the utility sink. Azamax has a 2 yr shelf life (comes in 4 oz) and Talstar 3 year (comes in 16 oz).