Butterflies and Caterpillars
Butterfly wing scales magnified at 60X.
Butterfly scales magnified at 200X. I wish the little microscope would take higher quality photos, this would be so cool if the lines could be seen on the scales. There is a lot of "noise" (little dots of light) in this photo. Maybe someday I'll have access to a really good digital microscope! Anybody got a spare $1500 ? ;)
This beautiful Monarch larva is munching on Common Milkweed, its only food. Milkweeds contain a cardiac glycoside in the leaves which the caterpillar stores in its body. The bright coloration is a warning to birds not to eat it. This picture was taken in late August, the butterfly that this caterpillar will become will migrate to Mexico and overwinter there. Most butterflies live only about a month. Monarchs that migrate delay their sexual maturity for several months. After mating in February and laying eggs in Texas, they will die. Reproduction is the "kiss of death" for these insects! A lot of children want to know if a caterpillar is a male or female, I tell them it isn't possible to tell the gender until it becomes a butterfly.
The tag on this Monarch's wing weighs very little, it doesn't interfere with the butterfly's flight. Anyone finding a butterfly with a tag should contact the researchers at the address to aid in migration information.
Well, in nature there are always exceptions to the rule! I photographed this Monarch Butterfly laying her eggs on a milkweed pod instead of under the leaves. It will be interesting to see if the eggs survive. She can't use the excuse of being an inexperienced first-time mother, because ALL of the Monarchs only lay one brood of eggs!
This female Monarch butterfly had just been released in the "Secret Garden" by a group of students at my school. The females do not have the dots (pheremone cells) on the lower wings that the males have.
This butterfly wing was magnified 10 times with an Intel Play digital microscope. The microscope takes low megapixel photos, so the picture quality is not quite up to par. The scales on the wings serve different purposes, they work as "solar collectors" to help warm the butterfly for flight; they give coloration to the butterfly; they help attract a mate. It is a misconception that butterflies can not fly if their wings are touched and the scales come off. The biggest danger is if the wings are damaged from being caught by awkward little hands, then the butterfly can no longer fly. It is best to use an insect net and a wide-mouthed jar for catching butterflies; don't keep them in the jar for long, they may flap around too much and break their wings.
Monarch butterfly forelegs magnified at 10x
Monarch butterflies appear to have only 4 legs, but they really do have 6. This photo, taken with my new digital stereomicroscope, shows the tiny, vestigial forelegs.
Note the tiny spiked feet near the head, these are the true legs of the caterpillar, the black and white ones are called "prolegs". The two antennae are called "whiplashes". The ones near the head are longer than the ones at the end of the abdomen.
A group of kindergarteners from my school anxiously await the release of this Monarch butterfly in the Secret Garden. They had raised the butterfly from an egg and followed the lifecycle in their classroom.
female Monarch butterfly laying an egg
on a milkweed leaf in my yard; it took only a couple of seconds, then she was fluttering off to another plant. The eggs are usually laid singly on the underside of the leaf to help protect them from predators. Butterflies taste through their feet. It is common to see them quickly touching leaves in search of host plants on which to lay their eggs.
Male Monarch Butterfly; Danaus plexippus
Milkweed Butterfly Family September 2006 It is easy to determine the gender of a Monarch butterfly, just wait for it to open its wings and then look for the black dot on the vein of the lower wings. This spot is where the male's pheremone is released.
This photo was taken of the wings of a dead butterfly. The wings were closed, the lower half of this photo shows the scales on the outside of the wing and the upper half the brighter scales of the inside wing.
Monarch butterfly; Danaus plexippus
) with us to Florida on a "hurricane Ivan clean-up trip" (Oct. 2004) as a chrysalis because I knew it would emerge before I got back home. It came out of the chrysalis in the container when we got to northern Alabama. We stopped at a rest stop near Gadsen and I released it on some goldenrod flowers. She was lucky, she got a 200-mile head start on her siblings in Oak Ridge! This beautiful little lady will fly to Mexico over the next few months to overwinter in the pine trees in the mountains outside Mexico City. If she makes the journey and survives the winter, in late February she will mate and begin the flight back north. She will lay her eggs in northern Mexico or southern Texas in March. After laying her eggs she will die. Her offspring will then fly on to places farther north about a month later, such as Oak Ridge, and in late April my students will enjoy watching their caterpillars go through their lifecycle! :)
Monarch caterpillar hanging in a "J"; crochets
the 6 true legs are on the thorax near the head). Then for several hours the caterpillar pulls air into its' body through the tiny breathing holes in the abdomen, called spiracles. The skin begins to loosen and the white stripes begin to take on a light green cast. Just before the big transformation takes place, the whiplashes ("antennae") begin to shrivel and the caterpillar straightens out. Suddenly, the skin begins to split just behind the head and the caterpillar wriggles violently to loosen the skin. The skin then slides up to where the caterpillar is attached by the black stalk called a cremaster. After a minute or two of hard wriggling the skin pops off and a light green chrysalis hangs where a caterpillar had been! (See next picture)
I had just tagged this Monarch butterfly before releasing it with a first grade class at my school. If the butterfly was later found by researchers in Mexico, the tag would identify where it came from.
, such as this one from a Monarch. It is hard to believe a caterpillar could emerge from such a small egg, it is only about 1 millimeter tall. Note the tiny lines radiating from the top of the egg. The mother monarch lays her eggs on only milkweed leaves (which she identifies by tasting them with her feet!), usually on the underneath side. A butterfly can lay over 500 eggs.
It is easy to see the wings of the butterfly through this transparent Monarch chrysalis. It is hard to believe there is an entire butterfly packed tightly into this inch-long chrysalis.
This is one of the first signs that may indicate the presence of a Monarch caterpillar; as they eat more and get larger, they produce large amounts of frass (a.k.a. "poop"). The caterpillar was on the leaf just above this one, the frass collected below it. There is a small amount of a chewed leaf that fell too.
Two Monarch chrysalises The caterpillar's body becomes a "soupy" mix of cells while it is in the chrysalis. During the 10 - 14 days that it is pupating, the caterpillar goes through a marvelous transformation. As the cells rearrange, wings slowly begin to show through the transparent shell of the chrysalis, a different kind of mouth is forming and the butterfly will soon develop scales and begin to turn black. The last 24 hours are the most amazing to watch as the chrysalis quickly turns from green to black and orange. Note the black line and the small gold dots on the green chrysalis. Some scientists believe they may help function in camouflage. The butterfly in the black chrysalis emerged a couple of hours after this photo was taken. The green one emerged a few days later.
Monarch Caterpillar and frass ("poop") on leaf below. This was one of my first photos to take with my new "emergency purse and pocket camera", a tiny 6 megapixel Nikon L11 point and shoot. I was very excited to find this caterpillar in the garden outside my room at school, I shared it with the children in the first grade class across the hall. The frass was what caught my attention to the caterpillar from my room! The teachers were laughing during lunch that only I could get excited about seeing caterpillar poop! :)
is probably about 1 day old and only about 2mm long. When it hatched, the first meal it ate was its egg shell. Next it ate the tiny hairs on the back of the leaf. This little caterpillar has already eaten a small hole in the leaf. Within the next 2 weeks, it will eat many leaves. The tiny black bumps on the top near the head and back end will grow into the "whiplashes" (antennae). In 2 weeks this little caterpillar will molt its' skin 4 times (the period between moltings are called "instars") and eat and poop a lot! Monarch caterpillars gain 3000 times their hatching weight by the time they are ready to become a chrysalis. I tell my students if they grew at the same rate as these caterpillars, by the time they became teenagers they would be as big as a school bus and weigh as much as 2 female elephants!
The butterfly loosens from the chrysalis and then, with no warning, the chrysalis splits open and the butterfly begins to emerge head first. I waited 45 minutes to catch this stage of metamorphosis in action.
