This may bean infestation of thrips – very small, yellow, brown or black, slender insects ranging from 1/16 to 1/8 inch in length.Adults and larval thrips feed using a punch and suck technique.

The damaged flowers become streaked and discolored. Infested leaves dry out, buds fail to open or flowers are deformed. Thrips tend to be more numerous on lighter-colored blooms, however; they will also feed on darker blooms.

Routine scouting will help in identifying infestations, so that you can treat before populations become more plentiful. A 10X magnifying glass or hand lens will aid in their detection. Thrips may also cause minor irritation if they get on human skin. Thrips populations are at their peak in the spring. They damage both foliage and flowers of many ornamental plants.

Thrips can usually be controlled with products containing acephate , bifenthrin, imidacloprid, permethrin, or potassium salts of fatty acids, among others.See the fact sheet below for other choices.

http://edis.ifas.ufl.edu/MG327