Invasive species / Gypsy Moths

Delilah Gonzalez

March 3, 2009

Period 1

What is an Invasive species ?

Invasive species is a phrase with several definitions. The first definition expresses the phrase in terms of non-indigenous species (e.g. plants or animals) that adversely affect the habitats they invade economically, environmentally or ecologically.

The second definition is an expansion of the first and defines an invasive species as a widespread non-indigenous species.

Conditions that lead to invasive species.

Scientists propose several mechanisms to explain invasive species, including species-based mechanisms and ecosystem-based mechanisms. It is most likely a combination of several mechanisms that cause an invasive situation to occur, since most introduced plants and animals do not become invasive.

Gypsy Moths

The gypsy moth, Lymantria dispar, is a moth in

the family Lymantriidae of Eurasian origin Originally ranging from Europe to Asia, it was

introduced to North America in the late 1860s and

has been expanding its range ever since.

Appearances

Egg masses are buff colored when first laid

Egg masses may bleach out over the winter months when exposed to direct sunlight and weathering.

Egg masses contain from a couple of hundred to about 1200 eggs

Female Gypsy Moth

female gypsy Moths continued

Females are generally light tan with brown or dark tan bars on their wings. Female Gypsy Moths do not fly. Egg masses are Found on the bark of trees, they also can be found under decks and on woodpiles, outdoor furniture and playground equipment. egg masses are most visible in the late fall after leaves have fallen. Egg masses are generally 1 1/2 inches long and shaped like teardrops. They appear to be wrapped in a tan-colored felt cloth. They are spongy, without noticeable exit holes.

Eggs of Gypsy moths

Gypsy moth egg masses are typically laid on branches and trunks of trees

During outbreaks they have been known to fly to ships in port and lay their eggs on the ships.

Moths

Introduced into the United States in 1868. Gypsy eat hundreds of other trees and shurb species including oak, apple, alder, aspen, basswood, birch, poplar, willow, hawthorn, hemlock, tamarack (larch), pine, spruce, and witch hazel. Gypsy moth usually avoids ash, butternut, black walnut, locust, sycamore, and yellow poplar (tuliptree).

Damage

Tree damage is caused by the insect larvae, or caterpillars, which emerge from their eggs beginning in early spring and continuing through mid-May. As might be expected, a caterpillar’s appetite increases with each moult.  Feeding continues until mid-June or early July when the caterpillar enters the pupal stage emerging, finally, as a moth. 

What happens to female and male moths

Both male and female moths exist only to reproduce once with the male moths flying to find the females who are too heavy to fly.  After the females lay their eggs from July to September, depending on location, moths of both sexes then die.

Work sited

www.Wikipedia.com

http://www.dcnr.state.pa.us/Forestry/gypsymoth/index.aspx

http://www.gypsy-moth.com/