Andromeda Lace Bug
Egg hatch ActiveStephanitis takeyai
2 host plants
Last updated
S. takeyai is documented in the Pacific Northwest but less commonly reported than S. pyrioides; field IDs rarely differentiate to species without microscopy, so actual prevalence on Pieris is likely underestimated. Pieris japonica is one of the most widely planted broadleaf evergreen foundation shrubs in Western Washington, making this pest site-relevant regardless of confirmed incidence data. GDD emergence thresholds are from mid-Atlantic studies; first-generation nymph emergence in the Puget Sound lowlands typically coincides with hawthorn first bloom, generally late March to mid-April. The cool maritime climate likely supports two generations rather than three.
— Chris Welch, ISA Certified Arborist
Quick Reference
Andromeda Lace Bug Egg hatch typically begins around 1415 GDD₃₂. As of May 11, 2026, all seven Puget Sound stations have passed this threshold (1851.2–2039.5 GDD₃₂), so Egg hatch is likely underway across the lowlands.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 11, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,040 | Egg hatch | — | — |
| Kent / Auburn | 2,030 | Egg hatch | — | — |
| Seattle / UW | 2,006 | Egg hatch | — | — |
| Olympia / Tumwater | 1,968 | Egg hatch | — | — |
| Tacoma / Puyallup | 1,935 | Egg hatch | — | — |
| Bellingham / Whatcom | 1,917 | Egg hatch | — | — |
| Sequim / Rain Shadow | 1,851 | Egg hatch | — | — |
Source: > About GDD₃₂ →
Monitoring & Action
Inspect undersides of Pieris leaves beginning in April (around hawthorn bloom). Look for tiny spiny pale nymphs aggregated near the midrib and black fecal spots that appear even before upper-surface stippling is visible. A hand lens helps. Check new growth first; nymphs prefer young expanding leaves.
No formally established threshold for ornamental plantings. Treat when stippling is progressing across multiple shoots or nymph populations are building. Early-season intervention targeting first-generation nymphs is significantly more effective than reactive treatment after adults have dispersed.
Feeding removes chlorophyll from leaf mesophyll cells, producing a stippled or bleached pattern on the upper leaf surface. Affected leaves appear silvery, grey, or bronze-tan. The underside of infested leaves shows dense black to brown fecal deposits (tar-like spots) and shed nymphal skins. Severe infestations cause overall bronzing, premature defoliation, and in repeated years, plant decline.
Cultural Controls
- Inspect leaf undersides in April before nymphs mature to adults; early detection is the most effective management tool.
- A strong stream of water directed at leaf undersides dislodges nymphs; wingless nymphs cannot return.
- Reduce plant water stress; drought-stressed Pieris sustains more severe damage.
- Partial shade can reduce population buildup; full-sun plantings tend to support higher lace bug densities.
- Remove and dispose of heavily infested leaves bearing visible fecal deposits and egg masses in fall to reduce overwintering population.
- Avoid broad-spectrum insecticides that disrupt predatory insects.
Host Plants (2)
Sources & References
Primary: UMD Extension
- Drake, C.J. & Maa, T.C. (1955). Stephanitisin China and Japan. Philippine Journal of Science. — original species description
- Neal, J.W. & Schaefer, C.W. (2000). Lace Bugs (Tingidae). In Heteroptera of Economic Importance, CRC Press. — host range
- Balsdon, J.A. & Mizell, R.F. (1996). Biology and management of lace bugs on azalea. UF/IFAS Extension. — lifecycle reference for Stephanitis spp.
- PNW Insect Management Handbook — Andromeda (Pieris japonica): Lace bug. Oregon State University.