Gypsy Moth in the Classroom |
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In this article... Gypsy Moth as a Classroom Tool Suggested Classroom Activities Timeline Rearing the Gypsy Moth in the Classroom
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Gypsy Moth as a Classroom Tool Considered a major pest in Michigan's forests and woodlots, the gypsy moth is proving to be a valuable classroom tool. The gypsy moth's hardiness and its ability to complete its life cycle in approximately 51 days allows students to view the hatching process from an egg mass, see the development of four or five larval stages (including shedding its skin), the metamorphosis from a caterpillar to adult (pupa stage), and the emergence of the adult moth before the process of laying egg masses begins the life cycle again. Egg masses can be found in most Michigan counties (eggs must go through a diapause or rest period during the winter to be able to hatch). Suggested Classroom Activities
Though it is a real pest in backyards and on thousands of acres of Michigan forests, the gypsy moth is an excellent classroom project. A low-cost, safe project showing the metamorphosis of an insect, the gypsy moth life cycle usually completes its four stages (egg, larvae, pupa and adult) in less than 60 days. The best time of the year to begin a gypsy moth project is in February or March. This allows students to view the complete process before the end of school year and does not pose a threat to the outdoor environment if any caterpillars or moths escape. In mid-May, after the classroom project has ended, gypsy moth caterpillars are hatching out in the wild and students will be armed with knowledge to help deal with gypsy moth problems. Egg masses can be found in most counties in the Lower Peninsula and parts of the Upper Peninsula, and gathering them can be a classroom project. A gypsy moth artificial diet is available at a low cost, and hundreds can be fed through the complete cycle for around $6. Classroom rearing results will vary depending on room conditions, humidity, food, time of year and other factors. For instance, eggs gathered in January and February may take three or four weeks to hatch, while those gathered in March take less time. The hatch from an individual egg mass usually is completed in two to three days. Little equipment is needed for raising the gypsy moths. An old aquarium, glass container of any kind or plastic bag will work to store the egg masses until they begin to hatch. Upon hatching, transfer the larvae to individual cups or containers. Gypsy moth hairs, called "setae," can cause allergic reactions in some people. Avoid this by limiting physical contact with the hairs of the caterpillars. Caterpillars can be transferred or examined using small paintbrushes or tweezers (the hairs stick to the brushes like Velcro). Using rearing cups with clear sides and/or lids allows easy inspection without disturbing the contents. Many projects involving gypsy moths can be done in class. In addition, simply raising the moths from an egg mass in a location available to students allows them to learn about insect growth and development. A number of educational resources are available (see page 23) listing many "field tested" activities using the gypsy moths in the classroom. If students are assigned individual caterpillars to raise, it is recommended to have some additional larva available in case some die. Newly hatched caterpillars are less than 2 millimeters long and are hairy. In the wild, they may remain around the egg mass for several days if weather conditions are unfavorable. Then they climb high up the trees and out to the ends of limbs. In a classroom, the moths will climb the sides and across the top of their container. The gypsy moth artificial diet includes wheat germ and vitamins and has an agar ingredient to make it set up in a custard-like texture for easy feeding. The diet can be refrigerated and should be changed if it becomes hard or moldy. Temperature and humidity are two key factors in raising gypsy moths. Caterpillar development increases as the temperature becomes warmer. The best temperature is thought to be 77 degrees. The best humidity range for raising caterpillars is about 50 to 60 percent. That rate is higher than what is found in most classrooms but can be achieved by placing a wire mesh platform in the bottom of the rearing container and adding one-half-inch of water in the bottom. The container must have a lid, but it can be loosely placed to allow some ventilation and prevent molding of the food. When a gypsy moth classroom project is completed, live caterpillars, pupae and adults can be killed by placing them overnight in a freezer. |
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