ELY – The sound of a low-flying yellow crop-duster airplane woke many Ely residents Friday morning as the Minnesota Department of Agriculture (MDA) began treatment of about 565 acres of the city to eradicate gypsy moth infestations.

Test flights were made late Thursday and spraying operations began before 6 a.m., according to MDA officials.

In 2015, MDA’s trapping program identified two isolated pockets of gypsy moth in the northeastern part of the state. Because of their locations, officials believed the gypsy moths likely arrived at the Ely and Two Harbors sites because of human activity.

In an effort to eradicate the moths before they continue their eventual spread, MDA officials are conducting two aerial applications of Bacillus thuringiensis var. kurstaki (Btk) over the same area. The second application will likely happen on Monday which is about 10 days after the after the first treatment.

Residents were notified of the spraying applications, but many in the treatment area were caught off guard Friday morning. Some people along Boundary Street could be seen peering out their windows or stepping out onto porches to see the activity.

A notification about the second application will be made at a later date.

Btk is a U.S. Environmental Protection Agency-approved bacterium with very low risk for humans or animals other than caterpillars. Btk is widely used within the organic gardening community.

The city of Ely hosted several community information meetings this spring as the eradication plans were finalized. A small but vocal group of citizens voiced concerns over potential health hazards from the aerial spraying operations.

Over the years, MDA has eradicated gypsy moth infestations on thousands of acres across the state using this method. These efforts protect forest health, property values and the state’s tourism industry, according to the MDA.

Gypsy moths are among America’s most destructive tree pests, having caused millions of dollars in damage to Eastern forests. The moths are now threatening Minnesota. If present in large numbers, gypsy moth caterpillars can defoliate large sections of forest. Oak, poplar, birch and willow are among their preferred hosts. The moths spread slowly on their own, but people can unintentionally help them spread by transporting firewood or other items on which the moths have laid their eggs.

To help area citizens stay informed, the MDA has set up an Arrest the Pest Info Line at 1-888-545-MOTH. The info line will offer the latest details about treatment timing. MDA’s website (www.-mda.state.mn.us/gypsymoth) also has information about gypsy moths and control efforts.

In anticipation of the second aerial treatment operation, MDA offers the following tips to residents in and around the treatment area:

For the moth treatment to work, it must begin early in the morning. Treatment may begin as early as 5:15 a.m. Residents may be awakened by the noise of the low-flying airplane. MDA apologizes for any inconvenience;

The airplane noise may spook pets, so residents may wish to keep them indoors during the treatment;

The treatment product has no known health effects for humans, but to avoid it residents may wish to stay indoors during the treatment and keep windows closed for a half hour after application; and

The residue does not cause damage to outdoor surfaces. However, soapy water will remove any residue on outdoor items.

One resident in the treatment area experienced a throat irritation for up to an hour after photographing the aerial spraying. Vehicles parked outside were covered with a residue that was washed off after a rain shower later that morning.

In Ely, the northern edge of the spray area boundary starts just north of the intersection of East Camp Street and 2nd Ave East and runs roughly parallel to East Madison Street. The western edge of the block follows 2nd Ave East south to Lookout Ridge Road. The eastern edge starts at the intersection of North 14th Ave East and East Madison Street running 1.1 mile south. There are no state or federal lands within the treatment block. (Go to http://gis.mda.state.mn.us/gmtreatments/ and type in “Ely” for a map of the treatment area.)