Mites - Broad mite injury on dahlia

Note twisted, hardened and distorted terminal growth. Young terminal buds can be killed and leaves turn downward. Injury can be confused with thrips damage, herbicide injury, physiological or nutritional disorders. Broad mites have a wide host range. Broad mites are difficult to see without the aid of a microscope. If characteristic symptoms are seen, send samples to a diagnostic laboratory for identification.

See fact sheet: Managing Cyclamen Mites and Broad Mites in the Greenhouse