I'm at my wits end with a recent chilli thrips infestation that has damaged gardens all throughout my area, especially roses. The chilli thrips are slowly but surely killing a majority of my 80+ roses, camellias, blueberries, and others. So far I've been aggressively pruning the top portions of new growth that they damage. These chilli thrips are completely new to my area. In Florida, where residents have been battling this tropical pest for much longer, the local Univerisity of Florida Entomology department has found that spraying an application or two of high concentration spinosad (Dow Agro Conserve SC) is one of the few ways to completely wipe out a population. According to UF, alternating strong spinosad foliar spraying with imidacloprid soil drench has been one of the few proven methods of controlling them, aside from buying predatory spider mites which are difficult to obtain.

Chilli thrips die off with cold weather, but in my area, with average lows of 45 in December/January, they will likely survive. Rarely do temperatures dip below 36 here, ever.

I have a bag of Merit 0.5% granules that I would like to use for long-term protection from these pests. Dow Agro Conserve SC is available publically by the quart and is ~$150, not worth it for me, at least not yet. Will I wreak havoc to the bug ecology in my garden if I apply these granules?

Any comments or suggestions are welcome,

Thanks,