Thrips

[Dimples]

They can come in on you or other things you bring in and out of the house. They can also blow/fly in open doors or windows. They’re small enough to fit through regular window screens.

I live on an avocado farm and the trees have thrips year round. It’s really not possible to avoid them in our climate. It’s a matter of when, not if. I’ve been doing an imidacloprid drench for all my houseplants a few times a year to keep them at bay. I need to do it again soon, as I’ve also noticed an uptick in thrip activity in the last few weeks. I’ll switch to something else this fall, don’t know what yet.

[MateoinLosAngeles]

Originally Posted by Dimples

I’ve been doing an imidacloprid drench for all my houseplants a few times a year to keep them at bay.

Which Imidacloprid product do you use? I have this granules from Bonide but they make a nasty paste when wet that I doubt epiphytes would appreciate. It’s the only product I found labeled for use indoors though. I would prefer to find something water soluble.

Originally Posted by Dimples

I’ll switch to something else this fall, don’t know what yet.

Keep us posted! I may update my first post with the suggestions that keep popping up.

[jiblylegs]

Originally Posted by MateoinLosAngeles

Which Imidacloprid product do you use? I have this granules from Bonide but they make a nasty paste when wet that I doubt epiphytes would appreciate.

Bonide carries a liquid concentrate of Imidacloprid here. It has instructions of how to dose it for various circumstances/plants. What I've been doing is take my 250ml squirt bottle, add 12.5ml of the concentrate, and then fill the rest to 250ml with water. I forget the math of how I came to figure it out, but I've never seen it damage my plants in any way. It's worked every time on insects.

[Dimples]

I use the Bonide tree and shrub. I take everything outside to be drenched*. My orchids will get a long soak in the imidacloprid solution and it will get poured over the foliage (just to get some on there) before they’re allowed to dry. Other houseplants get watered with the drench and allowed to fully drain.

*In the winter when we’ve had long stretches of too-cold weather for moving plants outside, I have very carefully drenched a few plants in our utility shower. The mixture **can not** be put down drains or gutters. It has to be disposed of on your own property, so don’t make extra.

[MateoinLosAngeles]

Originally Posted by jiblylegs

Bonide carries a liquid concentrate of Imidacloprid here. It has instructions of how to dose it for various circumstances/plants. What I've been doing is take my 250ml squirt bottle, add 12.5ml of the concentrate, and then fill the rest to 250ml with water. I forget the math of how I came to figure it out, but I've never seen it damage my plants in any way. It's worked every time on insects.

Thank you! I've always been hesitant about using insecticides as a preventative for fear of contributing to resistance. However, I'm starting to feel that the wide presence of thrips might warrant applications in Spring and Summer, assuming infestation will be inevitable.

The label says the product offers protection for up to 8 weeks. Could this be longer for slow growing plants like orchids?

[Clawhammer]

I found Imidacloprid marginally successful in treating thrips. Imidacloprid does not concentrate in sufficient quantities in the flowers to be effective. It works ok topically, but not as well as pyrethrin. I used it additionally to treat my catasetum as the thrips did attack those leaves and imidacloprid was more effective against thrips on catasetinae.

[Dimples]

Originally Posted by Clawhammer

I found Imidacloprid marginally successful in treating thrips. Imidacloprid does not concentrate in sufficient quantities in the flowers to be effective.

I’ll add that I don’t care if flowers still get munched on occasionally. I just want to prevent a full on indoor outbreak.

MLA, maybe you need two products? One for the plant and one for spot treating the buds?

[MateoinLosAngeles]

Originally Posted by Dimples

I’ll add that I don’t care if flowers still get munched on occasionally. I just want to prevent a full on indoor outbreak.

MLA, maybe you need two products? One for the plant and one for spot treating the buds?

Yeah that's what I was thinking. Imidacloprid alone won't cut it for the flowers but it definitely will help with Catasetums.

I've treated the Catasetinae with Imidacloprid and sprayed the leaves with Pyrethrin. For other plants, I only sprayed buds and flowers with a Pyrethrin aerosol, Stryker 54, which I bought years ago as part of a treatment I did for cockroaches in a rental apartment with lousy pest management. (Didn't last too long in that building!)

I want to do some more digging before treating any other plants with Imidacloprid. I'm also looking into a possible rotation between Imidacloprid and Spinosad. Apparently, Spinosad also has some systemic properties.

I did use PPE when spraying, and the space was left empty for hours. When I came back, I opened all windows. I will be running the air purifiers at max speed for the rest of the day/night.