Saturday, November 28, 2009

November 27, 2009 Day 12 All About J Form

We see our caterpillars are in various stages of beginning the process of pupating. From the Monarchs in Space Teachers Guide we understand that a caterpillar will empty its gut when it has finished developing and at that time produces frass with a pinkish hue. Pinkish frass is visible in the rearing boxes today. After emptying its gut, a monarch caterpillar will search for a sheltered, horizontal surface; as we see the caterpillars are orienting to the underside of the top of the rearing boxes.

To attach securely for the duration of the pupal (chrysalis) stage, the caterpillar spins a bed of silk and then a silk button in the center. It is from this button, with its anal prolegs (these are the pair of suction cup legs at the end of the caterpillar) anchored by crochets (tiny hooks on the legs) that the caterpillar releases it's hold and hangs like a letter J, upside down. It may, depending on the temperature, hang in this position for 12-16 hours.

Toward the end of the J stage, the caterpillar's color changes due to the chrysalis developing inside and the caterpillar usually straightens in its hanging position. What happens next, happens quickly. Simply stated, the caterpillar succumbs to contractions that cause the caterpillar's skin to split and move upward toward the silk button attachment, revealing the chrysalis that has been forming. When the skin reaches the silk button, the caterpillar's cremaster is released and pushed into the silk button and the chrysalis twists to secure the cremaster to the silk.

Over the next few hours as this process repeats itself in our rearing boxes, we expect to see these beautiful, lime green jewels of metamorphosis hanging where our letter J stage caterpillars are hanging now.

November 27, 2009 Day 12 The Landing

Welcome home Atlantis and the crew of the STS-129 Mission. The landing was beautifully executed at 9:45 am at the Kennedy Space Center. Meanwhile, more than 200 miles above planet earth, the Expedition 21 Crew on board the ISS is traveling at 17,000 miles per hour. Keeping them company, as you know, are three silent, lime green monarch chrysalides.

Tonight, as you gaze up into the night sky and consider the perspective you have on the heavens and our dear space travelers, you may want to consider as well, the perspective they have of the earth...and of us.

November 26, 2009 Day 11 First Chrysalides Formed!

Happy Thanksgiving! Caterpillars are home with me over break so that they can maintain their optimum growth at temperatures between 70 and 72 degrees and have 12 hours of daylight. These are the photos I collected at noontime and again just before midnight.

Our first J-stage caterpillars appeared in the morning; all other caterpillars were resting or eating. The two J-stage caterpillars were the ones who were the previously discolored, splotchy caterpillars we put in isolation and fed milkweed leaves for the past few days.

The next time I checked them was around midnight. Some caterpillars were still resting, some were eating, some seemed to be making silk beds, a few more were in J-stage, and finally, we had our first two chrysalides visible!

Note of interest: Visible in one photo is the pink-hued frass that is common for a caterpillar when it "empties its gut" prior to J-stage, and visible in another is a dark pile of caterpillar skin that was shed as the chrysalis was revealed.

For more photos, please click on the slide show at the side bar of this blog!