These are the 28 invasive insect species of 'greatest concern' in Pennsylvania

PENNSYLVANIA - The Commonwealth of Pennsylvania has cataloged 28 invasive insect species that threaten forests, agriculture and ecosystems – with many already spreading in Pennsylvania landscapes.

What we know:

According to the Pennsylvania Department of Agriculture, the "Insects of Greatest Concern" list includes 28 species. Some are already established and causing damage, while others haven’t yet arrived but are considered high-risk. 

The state coordinates efforts through the Governor’s Invasive Species Council and has a statewide invasive-species management plan. 

Pennsylvania’s Department of Conservation & Natural Resources (DCNR) also lists forest pests and diseases it monitors, such as emerald ash borer, spongy moth, hemlock woolly adelgid, and beech bark disease.

Because the spotted lanternfly was recently notable in New Jersey — where thousands of dead insects washed up on beaches — it’s a good moment to spotlight how problematic the insect is in Pennsylvania as well, where it causes economic and ecological damage.

Tier descriptions

Tier 1 – Early detection/prevention: 

These insects are not yet present in Pennsylvania. The goal is to watch closely and act quickly if they appear. Professionals prioritize surveying for them to catch new populations early.

Tier 2 – Eradication: 

These species exist in small, localized populations. Because their numbers are still low and treatments are available, eradication is possible if efforts are immediate and aggressive.

Tier 3 – Containment: 

These insects are spreading but not everywhere yet. They are usually too widespread to wipe out entirely, so management focuses on slowing their spread and protecting nearby regions from infestation.

Tier 4 – Local Control:

These species are established across the state. Eradication is not realistic, so managers focus on controlling them in specific areas to reduce damage and protect important resources like native species, agriculture or recreation sites.

Tier 5 – Monitor: 

These insects are not currently a major problem in Pennsylvania but are known to be invasive elsewhere. Officials monitor them for changes, since they could become invasive here in the future due to environmental or genetic shifts.

The 28 invasive insect species in Pennsylvania

Tier 1 – Early Detection / Prevention

• Spotted-wing drosophila (Drosophila suzukii)
• Asian garden beetle (Maladera castanea)
• Giant hornet (Vespa mandarinia) — Federal
• Asian longhorned beetle (Anoplophora glabripennis) — Federal
• Crape myrtle bark scale (Eriococcus lagerstroemiae) — Federal
• European fire ant (Myrmica rubra)
• Kudzu bug (Megacopta cribraria)
• Red imported fire ant (Solenopsis invicta) — Federal
• Spruce longhorned beetle (Tetropium fuscum) — Federal
• Winter moth (Operophtera brumata)
• European cherry fruit fly (Rhagoletis cerasi) — Federal

Tier 2 – Eradication

• Box tree moth (Cydalima perspectalis) — Federal (currently in Erie County only)

Tier 3 – Containment

• Allium leaf miner (Phytomyza gymnostoma)
• Cherry curculio (Anthonomus consors)
• Elm zigzag sawfly (Aproceros leucopoda) — Federal
• Fall armyworm (Spodoptera frugiperda)
• Lily leaf beetle (Lilioceris lilii) — Federal
• Sirex woodwasp (Sirex noctilio) — Federal
• Spotted lanternfly (Lycorma delicatula) — State
• Viburnum leaf beetle (Pyrrhalta viburni)

Tier 4 – Local Control

• Balsam woolly adelgid (Adelges picea)
• Brown marmorated stink bug (Halyomorpha halys)
• Elongate hemlock scale (Fiorinia externa)
• Emerald ash borer (Agrilus planipennis)
• Introduced pine sawfly (Diprion similis)
• Japanese beetle (Popillia japonica)
• Spongy moth (Lymantria dispar) — Federal
• Hemlock woolly adelgid (Adelges tsugae) — Federal

The full document of invasive insect species identified in PA