Tom Turpin
Professor of
Purdue University







The Gypsy Moth Is A Real Vagabond

The gypsy moth is a well-known pest insect. Larvae of these moths feed on trees. They prefer oaks but do well on aspen, birch, apple, and even conifers. Trees may be completely defoliated by the feeding of this insect.

The gypsy moth now occurs in all New England states, areas of Canada, and the states of Maryland, Virginia, Ohio, and Michigan. But the insect hasn't always been a resident of North America. The gypsy moth is of European origin. It is one of the notorious introduced insects that have become pests in the United States.

The story of the gypsy moth in the United States begins in Medford, Mass., a suburb of Boston. The year was 1869. Leopold Trouvelot, a French astronomer, was working at the Harvard Observatory. Trouvelot also was concerned over the plight of the French silk industry that, at the time, was in dire straits. The problem was that the French silkworms were afflicted with a disease. So Trouvelot the astronomer decided to breed a strain of silkworms resistant to the disease by crossing them with the gypsy moth. He imported gypsy moth eggs from his native France to his home at 17 Myrtle Street in Medford.

No one knows for sure how the insect escaped, but in 1879 Trouvelot sold the house and returned to France. The new owner soon discovered fuzzy caterpillars eating the leaves of the trees in the yard. The rest is, as is often said, history. The insect began to spread from the trees around 17 Myrtle Street in Medford and continues to extend its range today.

No one knows for sure how the gypsy moth got its common name. It has been suggested that an English butterfly collector dubbed the insect the gypsy moth in 1742, probably because of its vagabond habits. Linnaeus called the insect Phalaena dispar. The term “dispar” referring to the disparency in form between the male and female moths. The males are typical winged moths while the females are wingless.

The insect has never become a problem in England. In fact, there have even been attempts to reintroduce the insect to the British Isles, apparently without success. On the European continent, the insect has been a pest, sporadically causing major problems from France to Japan.

Attempts to keep the gypsy moth under control in the United States have included massive spray programs including DDT applications in the 1950s. Biological control agents including bacterial and viral diseases and predator and parasitic insects have been investigated and introduced in attempts to limit the success of this insect. A sex pheromone of the female gypsy moth, called disparlure, has been identified and synthesized and is used to trap males to determine their distribution and abundance.

In spite of the best efforts of modern science, the gypsy moth is here to stay. It sure would have been better if that French astronomer Trouvelot had kept his eyes on the stars and left the gypsy moth in France!


Writer: Tom Turpin
Editor: Andrea McCann