Mystery Defoliation of Yellow Bells and Hibiscus in Arizona: Slugs, Earwigs, or Caterpillars?

Leaves vanished overnight—half eaten, edges browned, white specks at the start. No insects visible day or night. Ant spray and soap-water gave little relief. The expert ruled out aphids and disease; the rapid consumption points to nocturnal feeders: slugs, earwigs, or caterpillars. Slugs are the prime suspect—they feed at night, leave silvery trails, and hide by day.

The white spots are likely unrelated (possibly mineral deposits or fungal spores). Nighttime inspection with a flashlight, or placing damp cardboard traps overnight, can reveal the culprit. A photo would help confirm.