Honeylocust plant bug

Diaphnocoris chlorionis

3 host plants

Last updated

Data Maturity Baseline

This profile contains verified pest data from extension databases. Regional field notes and expert review are in progress.

Honeylocust plant bugs appear on honeylocust foliage in late spring and early summer, feeding by piercing plant tissue and sucking sap. The small bugs (less than 0.25 inch) are brown or darkly colored and congregate on younger leaves. Feeding damage causes yellowing, stippling, and leaf curling; affected foliage may eventually brown and drop. Heavy infestations reduce tree vigor and aesthetic appeal.

Monitor honeylocust trees from late May through July for plant bug presence and early stippling. Remove heavily infested shoots by hand if populations are light. For active populations, apply insecticidal soap or neem oil targeting nymphs and adults. Horticultural oil in late winter targets overwintering adults. Most infestations self-regulate above 80 degrees Fahrenheit.

Quick Reference

Order
Hemiptera
Type
sucking-insect
Host Plants
3
GDD₃₂ Egg hatch early instar
1,799
Indicator: Blue false indigo first bloom

Honeylocust plant bug Egg hatch early instar typically begins around 1799 GDD₃₂. As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂, approximately 206 units before the expected threshold.

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,593 Pre-season Egg hatch early instar 206
Seattle / UW 1,554 Pre-season Egg hatch early instar 245
Kent / Auburn 1,537 Pre-season Egg hatch early instar 262
Olympia / Tumwater 1,505 Pre-season Egg hatch early instar 295
Bellingham / Whatcom 1,483 Pre-season Egg hatch early instar 316
Tacoma / Puyallup 1,472 Pre-season Egg hatch early instar 327
Sequim / Rain Shadow 1,434 Pre-season Egg hatch early instar 365

Source: UMD IPMnet catalog. Sources: UMD: extension.umd.edu. About GDD₃₂ →

Host Plants (3)