Some people wil tell you to clean up all the debris in your garden which might give some plant for the thrips to over winter, but keep in mind that also eliminates any place for the beneficial insects to over winter. Work on the soil, test it for soil pH and nutrient balance, and whatever else is needed to make that soil into a good, healthy soil that will grow strong and healthy plants better able to resist insect pests. Also work on having "stuff" growing in the garden that will help hold the beneficial insects, those that will aid greatly in controlling thrips.
I've not seen any thrips in my gardens in many years, a few Japanese Beetles, some sawfly larva, occassionally a leaf miner or two (especially in the self seeded Columbine), but few others.

Thank you, Kimmsr. I wonder if i do my gardens a disservice by being a bit of a "neat freak." I'm quick to pick up debris, especially fallen rose petals, though it's hard to get every last little bit up. I figure i'm compensating for the lack of "rot" by top dressing with compost every year.

What other "stuff" would you recommend i grow to attract beneficials?

Is it a good sign the thrips are nearly gone, or have i simply observed their natural life cycle?

Also, i've been reading (and clearly need to read more) about beneficial neematodes? Would that help?

Green Lacewings, Wasps, dragonflies, and a number of other predators of Thrips cna be encourage to hang around with such flowers as Queen Annes Lace and flowers that form a similar head.
Since nemtaodes work in the soil they are not a good control for thrips which apparently get blown in on the wind and do not overwinter in the soil.

Estreya, I'm glad you asked that question because I have been wondering the same thing. I, too, was plagued with thrips earlier in the year, and things are better now. I don't know if it was because of some beneficial insects or because I sprayed with Ultrafine horticultural oil and baking soda at least three times.

However, I read in a book on Roses that I have (Foolproof Guide to Growing Roses, by Field Roebuck) that the "best approach is to break the two-week life cycle by destroying the larvae in the soil, along with the adults on the plant. You can accomplish this to a great extent by drenching the soil with beneficial nematodes early in the year and then spraying the young growth and the flower buds with a neem oil extract."

Then I read somewhere on this forum or the regular roses forum that j.song uses Spinosad; says it's safer, natural, and most effective against chewing and eating insects. He or she applies it with Ultrafine to control thrips. You can get Spinosad from Planet Natural. It's also called Monterey Garden Insect Spray. That company also sells beneficial nematodes $24.95, free shipping, apply in early spring. www.planetnatural.com, or www.hydro-gardens.com.

I am planning on using the nematodes for sure next spring. Hope I don't forget.

Marlene

You could spend a lot of money on "stuff" to control many pests and plant diseases but my experience is that if you get your soil into a good, healthy condition so you grow strong and healthy plants you will see many fewer pest and disease problems. There are those that doubt that because they are still hung ip on the "conventional" way to garden and do not understand the basic premise of Organic Gardening that plants growing in a good, healthy soil will be less desrieable to those pests and diseases.