Why Are There Helicopters Flying Around West Michigan?

Have you been hearing helicopters in your neighborhood? I've seen multiple people asking online what's the deal with the helicopters in West Michigan.

Of course there are the conspiracy theories about secret spy missions or aliens, but the real reason is a particular kind of invasive insect.

Helicopters Spraying For Spongy Moths in West Michigan

Formerly known as the Gypsy Moth, Spongy Moth can damage and even kill trees.

Michigan DNR

Each year around this time, local governments work with pesticide application companies that bring helicopters to perform spongy moth spraying treatments.

The exact date and time of spraying depend on weather conditions, the insect stage, and leaf development. If spraying is happening in your neighborhood, you should receive a notice from the City.

Here's a release from Walker on the spraying program and another from Wyoming.

What is a Spongy Moth?

Spongy moth is an invasive species that has been in Michigan for more than 40 years.

Michigan DNR

Spongy moth egg masses can contain over 1,000 larvae that hatch into leaf-eating caterpillars.

City of Grand Rapids

When the caterpillars significantly defoliate trees, the trees become weaker and vulnerable to diseases, which could kill them.

How to Identify Spongy Moth

According to the Michigan DNR:

Spongy moth caterpillars emerge from tan, fuzzy egg masses in April and feed on leaves through late June.
Caterpillars are hairy, with a yellow and black head and 5 pairs of blue spots, followed by 6 pairs of red spots.
Mature caterpillars are 1.5 to 2 inches in length.
Leaf debris and small, round frass found under trees are indications of gypsy moth infestation.
Male moths' wings have a wavy pattern of brown to dark-brown and span 1.5 inches.
Female moths are larger than males and do not fly. Wings are white to cream with wavy black markings.

Michigan DNR

You can find out more about Spongy Moth here.