Lace wings and lady bugs are predators of thrips. Spray with insecticidal soap or Neem Oil from the time blooms are in tight bud, through full bloom. Thrips hide within the petals. To see them, fold back the petals, exposing the flower base. The bottom leaves on the plant appear to be covered with fine dots of yellow on the top and undersides of leaf surfaces.
Leaves turn yellow and fall off.
Microscopic in size, these insects may be visible to the unaided eye as reddish specks. They can spread very quickly, and favor the hottest days in midsummer. First try spraying the insects with a forceful blast of water to dislodge them, do this early in the morning once a day for 3 days. If this fails then spray with insecticidal soap or Neem Oil during periods which favor the growth and spread of this insect. Direct spray upward, to the undersides of the bottom leaves.