Native Butterflies Take Flight
As the butterfly house winds down for the season, make sure not to miss out on seeing us. There are a few of us left munching away on the hostplants in the butterfly house before we prepare to overwinter. Below are different caterpillar instars (ages) of our spice bush butterflies and one red admiral who just emerged on 9/13/18. Come and enjoy the warm weather with our butterflies.
7/27/18: This week we are seeing our eastern black swallowtail caterpillars growing very quickly. There are a few that have one more instar (stages of growth for a caterpillar. They usually go through five instars and molt or shed their skin between each instar) and then they will be ready to transform into a chrysalis.
Second Instar of a black swallowtail
7/23/18: Monarchs having been laying eggs on the milkweed and we have just spotted our first few caterpillars emerging. Generally, you will find them on the undersides of the leaves where a little chewing is present.
7/19/18: New visitor to the butterfly house. The flowers are so appealing that we have an Eastern Comma, Polygonia comma join our other butterflies. As far as we know, no one brought in the butterfly, it just entered in of its own accord.
7/5/18: Program Director Leila Nordmann caught this Cecropia moth, North American's largest native species, warming its wings as it emerges from its cocoon. The moth has a lifespan of only 2 weeks!
6/15/18: The sunnier, warmer weather has encouraged our butterflies to eclose or hatch out of their chrysalides. Currently, there are monarchs, eastern black swallowtails, and painted ladies flying around the butterfly house. Our newly, redesigned chrysalides case is helping our butterflies find better places to hang from such as branches and black felt. Being able to hang easily allows for the wings to inflate or have meconium pumped into the tubular veins of the wings, spreading them like sails. The wings then dry and harden allowing the butterfly to lift off and fly.
Arrival of the Silkworms
What look like small, black poppy seeds are actually the eggs of a silkmoth, Bombyx mori. These eggs will hatch out into slender, white caterpillars, commonly referred to as “silkworms,” that feed on mulberry leaves. In this case, our mulberry leaves are crushed into a dry powder, which we prepare by adding water and microwaving.
Because of over 5,000 years of domestication, Bombyx mori is no longer found in the wild. It has been transported from China by humans all over the world to where mulberry trees are found starting in the 6thcentury. In North America the red mulberry tree (Morus rubra) is native, and the first silkworms arrived on the East Coast from Europe in the 1700’s.
Why do we have them at the Fairbanks Museum? They're fascinating and bring a new dimension to our Butterfly House. You might recognize their value from any silk fabric. The silk comes from the cocoons of these silkmoths. All silkmoths produce a silken cocoon but what is special about this particular species is the continuous single strand it makes to form its cocoon. That single strand can be up to 3,000 feet long and is very strong fiber for its weight. To produce 1 pound of silk, you would need between 2,000 and 3,000 cocoons. That one pound would consist of about a 1,000 miles of silk filament!
In 6 to 12 days, we should see our first caterpillar begin to hatch out from these eggs.