Pest profile

Cranberry Rootworm Beetle

Rhabdopterus picipes · Coleoptera: Chrysomelidae[2]

Cranberry rootworm beetle is a night-feeding beetle that chews curved holes in the leaves of landscape shrubs.[1]

No licensed photo of this species is available yet; the identification notes below describe what to look for.

How to identify it

  • Adults are shiny dark bronze-black beetles about 1/4 inch long and 1/8 inch wide.[1]
  • Damage is curved, C-shaped or elongated holes that can look like hail damage.[1]

Where it lives

HGIC covers it as a pest of woody landscape shrubs in South Carolina.[1]

US map: public records from 3 states since 1990 (GBIF).

Biology and life cycle

Adults hide in mulch by day and feed for several weeks in late spring and early summer.[1]

Larvae feed on roots into fall, overwinter deep in soil, pupate in early spring; one generation a year.[1]

Damage and signs

  • Hosts include azalea, rhododendron, camellia, blueberry, hollies, roses, redbud and oakleaf hydrangea.[1]

Health risk

It feeds on plants; Clemson HGIC mentions no risk to people.[1]

Control

Prevention

Keep shrubs healthy with weekly watering in dry spells, soil-test-based fertilizing and a 3 to 4 inch mulch layer.[1]

Pesticides

After flowering, a labeled foliar spray on leaves and mulch, or an imidacloprid soil drench, controls it; never spray during bloom.[1]

Common questions

What's making curved holes in my camellia leaves?
Cranberry rootworm beetles feeding at night leave curved, C-shaped holes.[1]
Why can't I find the beetles during the day?
They hide in mulch during daylight and feed at night.[1]

Sources

  1. Clemson Cooperative Extension, Home & Garden Information Center, “Cranberry Rootworm Beetle on Landscape Shrubs (HGIC 2014).” hgic.clemson.edu/factsheet/cranberry-rootworm-beetle/ (accessed 2026-10-06)
  2. iNaturalist, “Rhabdopterus picipes taxon page (order and family).” www.inaturalist.org/taxa/229851 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.