Origin of Gypsy Moths in the United States

This section provides information about how gypsy moths came to the United States.

E. Leopold Trouvelot

E. Leopold Trouvelot

Gypsy Moth History

The gypsy moth was brought to North America from France by Mr. E. Leopold Trouvelot. His purpose was to breed hybrid silkworms that would be hardier than the Chinese species and that could be used to establish a silk industry in the United States. By 1865 he had a million caterpillars feeding under protective netting at his home in Medford Massachussets. In 1869 some of them escaped and were apparently scattered by a windstorm.

By 1881 the gypsy moth caterpillars had become so common in the neighborhood of Trouvelot's old home, that the villagers in Medford considered them a local nuisance.

The population of gypsy moth caterpillar exploded during the spring of 1889. The year before had been a good one for insects, and gypsy moths had flourished and laid record numbers of eggs. Hatching in April and May of 1889, millions of gypsy moth caterpillars stripped leaves from trees yard after yard and street after street in Medford. Caterpillars covered tree trunks, fences, and sides of houses.

Gypsy moth spread map

Gypsy moth spread map
University of Wisconsin

From this unfortunate start in Medford Massachussets, gypsy moths have now spread to many other portions of the United States

From 1892 to 1900 gypsy moths were confined to the extreme eastern portion of the State of Massachusetts.

By 1914 they had spread to New Hampshire, Maine, Rhode Island, and Connecticut.

By 1941 they were in Northeastern Pennsylvania and in extreme eastern New York State.

By 1981 they were all over Pennsylvania and New Jersey.

They have now spread to many other states, including Michigan and Wisconsin, as shown on the map on the right.

Gypsy Moths are now also in Virginia, West Virginia and Oregon. How did they get to Oregon? It is believed that they hitchhiked on a car or truck.

They continue to spread.

Follow this link to see efforts over the years to rid the country of Gypsy Moths: Gypsy Moth Wars