If you see tiny, wormy little bugs, dark winged insects or bronzed discoloration on the leaves, you may have thrips. Learn how to get rid of them!
www.growweedeasy.com
Blue or yellow sticky traps.
From Biobest Sustainable Crop Management website.
Yellow traps are generally used as the colour attracts whitefly and thrips as well as leafminers and fungus gnats. However, if the key pest target is thrips we recommend using blue sticky traps as they are the most effective at attracting this pest.
I've used natural predators, Amblyseius cucumeris with great success too.
Amblyseius are used to control thrips by growers in commercial horticulture.
www.defenders.co.uk
I hope that helps.