The Effect of Gypsy moths on Pennsylvania’s Forests

1. The Effect of Gypsy moths on Pennsylvania’s Forests By Luke Parr Luke Parr

2. What is Gypsy Moth? • Gypsy moth is a moth in the family Lymantriidae. It is one of America’s biggest forest pests. Gypsy moths like to feed on the foliage of oaks and aspen, but will also effect hemlock s and pines. Gypsy moths are defoliators and cause tree mortality in many cases if the defoliation is severe enough. Luke Parr

3. Gypsy Moth Defoliation The effects of defoliation on trees is very hard and sometime may be sever enough to cause tree mortality. If less 50% of a tree’s crown is defoliated; the tree will have a slight reduction in radial growth. If more then 50% of a tree’s crown is defoliated though; the tree will refoliate and produce a second flush. A healthy tree can usually withstand 1 or 2 consecutive defoliations of greater then 50%. Weak trees or trees that have been weakened by previous factors such as droughts are killed after only one defoliation of greater then 50%. These trees can also experience a radial growth reduction between 30% to 50%. Luke Parr

4. Introduction of Gypsy Moth into America. • The reason for the gypsy moth problem in the United States today is because of this man; Etienne Leopold Trouvelot. Trouvelot was a painter but had an interest in entomology (the scientific study of insects). His main interest was the study of native silkworms that might be used for silk production. Although the reasons are unknown, Trouvelot one day returned from a trip to France with some gypsy moth egg masses. He was culturing them on some trees in the back of his house when some of the larvae apparently escaped. Trouvelot knew the potential danger and notified the local entomologists, but no action was taken. Luke Parr

5. Gypsy Moth Control Natural Human • Deer Mice– Considered the most important predator of low density gypsy moth populations. • Tachinid Flies– They parasitize moth populations. • Braconid Wasps- Also parasitize moth populations. • Nucleopolyhedrosis - A naturally occurring organism, that has been developed as a microbial pesticide. • Bacillus Thuringiensis - A microbial and biological. It is a crystal protein toxin that kills the cells lining the insect gut. Its the most commonly used pesticide. • Acephate – A pesticide that is used to treat individual trees. • Carbaryl - At one time it was the most widely used pesticide in the gypsy moth program. • Diflubenzuron – A highly restricted use pesticide that is applied by certified applicators only. Luke Parr

6. Gypsy Moth Life Cycle • Eggs- Gypsy moth eggs are laid in egg masses. They are the size of a quarter. They are present from late August through April. • Larvae- In this stage gypsy moth resembles a caterpillar. In this stage they tend to feed on foliage. • Pupae- In this stage the caterpillars shed their skin one last time and turn into a dark brown shell like insect. This takes place between June and early July. • Adult- Adults appear in late July and early August. They do not feed in this stage. The female gypsy moth, which does not fly, will lure in a male gypsy moth to mate with. She will then lay her eggs and die. Then the cycle continues all over again. Luke Parr

7. Differences Between Male and Female Gypsy Moths Male Female The male gypsy moths are grayish-brown and can fly. Female gypsy moths are larger then males. They are whitish with black marks and cannot fly. Luke Parr

8. Trees Affected • Maple • Elm • Oak • Apple • Alder • Birch • Poplar • Widow Trees • As a gypsy moth grows it is also know to feed upon evergreens like pine and spruce. Luke Parr

9. Gypsy Moth Defoliation in Pennsylvania Luke Parr

10. Sources • http://www.fs.fed.us/ne/morgantown/4557/gmoth/atlas/ • http://en.wikipedia.org/wiki/Gypsy_moth • http://www.gypsy-moth.com/ • http://www.ivyhall.district96.k12.il.us/4th/KKHP/1insects/gypsymoth.html Luke Parr