Spotted lanternfly egg season arrives in Plymouth, Canton

Wayne County is one of eight Michigan counties with a confirmed spotted lanternfly population. Plymouth and Canton residents are now in the thick of fall egg-laying season for the invasive pest, which runs from late summer through the first hard frost.

The Michigan Department of Agriculture and Rural Development (MDARD) and the Michigan Department of Natural Resources (DNR) updated the statewide count on Thursday, Sept. 10, after confirming new populations in Berrien and Washtenaw counties. Wayne County's infestation dates to 2024, when the pest was detected there and in neighboring Monroe County, according to MSU Extension. High-density infestations in Toledo likely fueled that spread.

Spotted lanternflies feed on more than 70 plants, including grapes, apples, hops and hardwood trees. They suck sap from host plants and secrete a sticky liquid called honeydew. The honeydew breeds black sooty mold that can kill plants and foul outdoor surfaces. It also attracts yellow jackets, flies and ants.

The insect's favorite host is tree of heaven, an invasive tree common in urban areas. MSU Extension notes that high densities of spotted lanternfly are frequently found near large stands of the tree. Grapevines and hops are also among its preferred targets, according to Patch, which reported on the threat to Michigan's grape-producing regions.

"While spotted lanternfly can impact plants and cause crop damage when populations are high, it does not pose a risk to human or animal health," MDARD Director Tim Boring said in the state's Sept. 10 announcement.

What to look for

Adults are roughly one inch long with gray-to-brown folded wings marked by black spots. When the wings open, bright red hind wings with black-and-white bands appear.

Egg masses show up in fall. They look like old chewing gum, about one inch wide and two inches long, coated in a shiny gray or tan substance. Most masses contain 25 to 35 eggs, though a large mass can hold up to 60.

What Plymouth and Canton residents should do

Because Wayne County already has a known infestation, the guidance is straightforward: squish spotted lanternflies on sight. No report is needed.

For egg masses, MSU Extension recommends scraping them into a bucket or plastic bag filled with water and dish soap to kill the eggs. A handheld or wet/dry vacuum can capture nymphs or adults, which should then be dropped into the same solution.

Residents receiving shipments from other states with known infestations should check goods and packing materials for egg masses. Before leaving any infested area, check vehicles, firewood and outdoor furniture for hitchhikers.

Since 2022, MDARD and partners including the DNR, MSU Extension and the U.S. Department of Agriculture have monitored more than 100 locations across Michigan. Residents outside the eight counties with confirmed populations who spot the insect should photograph it, note the date and location, and report through the DNR's Eyes in the Field online tool.

With tree of heaven common in neighborhoods across Plymouth and Canton, checking backyard trees and outdoor surfaces for egg masses before winter is the single most effective step homeowners can take.