Gypsy Moth

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The Gypsy Moth is an insect in Wisconsin that deserves more attention. The Gypsy Moth is considered to be a very destructive Invasive Species. The caterpillar that metamorphose into the moth especially is capable of great damage to many different kinds of trees. The moth has made its way into Wisconsin within the past 30 years, and has continued to spread to almost every corner of the state. Some counties are considered to be infested with the Gypsy Moth. The conditions in Wisconsin are favorable for the insect to thrive.


The gypsy moth is native to Russia, Europe, and North Africa. It is typically found around the Mediterranean Sea. The Gypsy Moth is usually held in check by many parasites, predators, and the freezing winters of its homeland. This helps keep the moth's population in check. Professor L. Trouvelot brought the Gypsy Moth over from its native region into North America around 1868. His intent was to breed it with a silkworm. [1] The moth accidentally got released in Massachusetts and bred like crazy. The moths steadily increased in population and expanded westward into Wisconsin in the 1970's.[2]

What does it look like?


The eggs are laid by the female in masses. They can be identified from their "fluffy" looking eggs. The eggs can range in color from white to brownish orange.[3] The eggs are laid in dime size masses and lay dormant through the winter. The eggs hatch in spring to feed off the many blossoming trees.

A nest of Gypsy Moth eggs

Caterpillar Form

The caterpillar form of the Gypsy Moth is surprisingly easy to identity. They usually start off very small and grow rapidly to be roughly three inches long. Physically they are easy to identify with their yellow heads and hairy bodies. What stands out most about them is the distinct pattern of dots on their backs. They have 5 pairs of blue dots followed by 6 pairs of red dots.[4] Most of us have seen this destructive insect without even knowing it, although there are a few other insects who look similar to the Gypsy Moth in caterpillar form. It takes one year for the insect to complete its whole life cycle.

Adult Female Moths

The adult female Gypsy Moth has a large cream colored head and a very wide abdomen. The wings of the female are cream colored or sometimes a very light brown color with a zig zag like pattern on them. They also have long thin antennae as well as patches of dense tiny, golden hairs all over the female's head. The wingspan of an adult female gypsy moth is about 2 inches, the main difference between the male and the female is that the female can only fly shorter distances compared to the male moth. The females are almost always larger than the male moths. The female moth grows up to be an estimated 2.5 inches long when fully matured.[5]

A female gypsy moth (top) and a male gypsy moth (bottom)

Adult Male Moths

The male moths only grow to be about 3/4 of an inch long and have large feathery antennae. Their wings have been described as brown and/or grayish colored. The males are easily identified and distinguished from the females. The males use their antennae to locate and attract the female moths in order to mate, like many other insects do too.[6] His antennae are much larger than the females antennae.

Where is it in Wisconsin?

The gypsy moth was first found in Wisconsin in the 1970’s. The moths infiltrated Wisconsin from the West and spread throughout the state. By 1989 it had made its new home on Wisconsin's eastern half, including Green Bay and Milwaukee.[7] They have been found in almost every county in Wisconsin and the eastern half of the state is considered infested with the Gypsy Moth. They are more prone to be found in heavy woods and somewhat warmer weather. Green Bay is a place the moth has found to be enjoyable, with its large forests supplying the moth with a ton of food, and its warmer, humid climate in the spring and summer months.

What does it consume?

The Gypsy Moth is known to eat almost any tree/plant, feasting on almost 300 different species of plants. The caterpillars that hatch from the larvae can do significant damage to large trees. About once every ten years the gypsy moth will reach outbreak levels, spreading their destruction throughout the state. Studies show the caterpillar form prefers to eat hardwood trees. They have been known to attack certain species of trees as their favorite such as; oak trees, apple trees, some poplars, alder trees, hawthorn trees, and willow trees.[8] In the caterpillar stage of life, the Gypsy Moth has been known to completely destroy the leaves off trees, killing the tree. The feeding usually starts at the top of the tree, so if the tree is rather tall it may not be known that there is an infestation until it is too late. Once the caterpillars get older, they work their way down the tree trunk and seek shelter from predators and weather on the ground. Once it becomes night, the older caterpillars then move back up the tree to feed off the leaves in the canopy of the tree, often when out of sight.[9]

Damage caused by the Gypsy Moth caterpillars

What is being done about it?

Wisconsin has started to quarantine some counties, especially in the eastern half of the state. This quarantine sets restrictions on the outdoor items that can be taken from the quarantined counties to non-quarantined counties. These items include; Christmas trees, firewood, logs, outdoor furniture, and other outdoor items.[10] The best way to avoid the spread of the gypsy moth is to be aware of what it looks like. Recognize what it looks like in all stages and be prepared to dispose of it when possible. The best route to eliminate the threat of Gypsy Moths is to contain them.


  1. "Alien Profile: Gypsy Moth," Eek! Environmental Education for Kids, Accessed 2017-04-27,
  2. "Gypsy Moth," Wisconsin DNR, Accessed 2017-04-27,
  3. "Gypsy Moth Identificaiton," Washington State Department of Agriculture, Accessed 2017-04-27,
  4. "Gypsy Moth Identificaiton," Washington State Department of Agriculture, Accessed 2017-04-27,
  5. "Gypsy Moth," Orkin, Accessed 2017-05-02,
  6. "Gypsy Moth," Orkin, Accessed 2017-05-02,
  7. "Pest Alert," USDA, Accessed 2017-05-02,
  8. "Gypsy Moth," Orkin, Accessed 2017-05-02,
  9. "Gypsy Moth," Orkin, Accessed 2017-05-02,
  10. "NR 40 Reasonable Precautions for Quarantined Species: Gypsy Moth," Wisconsin DNR, Accessed 2017-05-02,

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