Hardy hibiscus recurring problem

Asked July 25, 2016, 4:11 PM EDT

Hardy hibiscus pest needs identification and ecologically safe way to attack the pest. I noticed some white substance n leaves and stem. Leaves shredded. See pics

Montgomery County Maryland

1 Response

This looks like damage by the hibiscus sawfly. The photos are out of focus and we cannot say what the white substance is and the black may be frass.
The adult sawfly is a small black fly and the larvae are pale green. The larvae feed on the foliage. Look for this. You can handpick if the infestation is light or spray with horticultural oil. Follow all label directions and do not spray in high temperatures. See our website for photos and more information http://extension.umd.edu/hgic/sawflies-flowers