If serious damage is occurring, insecticidal soap is recommended. As with any pesticide, read and follow all label directions and precautions. The twospotted spider mite and other mite species can be a problem on daylilies. Mites are not insects but are more closely related to spiders. They have piercing mouthparts that allow them to puncture plant tissue and suck plant sap.
Mites tend to be more of a problem during hot, dry periods.
Over time, some spider mites produce a fine web on leaves, which protects their eggs and young. With a light infestation, daylily leaves and flowers develop yellowish speckles. Partially as a result of the mite s tiny size, this damage often goes unnoticed until damage is more severe. With a heavy infestation, the speckles will run together and entire leaves can become bleached and die. Along with leaf decline, growth is stunted.