Thrips Several species of thrips are know to infest daylilies. Control thrips by starting early in the growing season with a pesticide having either a systemic or long residual action. To repeat, do not use the pesticide Kelthane. Slugs and Snails Slugs and snails feed on the young, tender tissues, causing ragged edges and holes. They feed at night and hide during the day in cool, moist places, such as in mulch, under rocks and bricks, and in dead foliage.
Sanitation helps to control slugs and snails.
Otherwise, control requires using pesticides which are targeted specifically at these pests. There are other pests that attack daylilies. Other insect pests which have been reported affecting daylilies include cutworms , tarnished plant bugs, cucumber beetles , wasps, Japanese beetles , grasshoppers , and periodical cicadas. Bulb mites may be involved in the transmittal of crown rot. Deer will sometimes eat daylily flower buds.