Cecropia Caterpillar Growth: Moth larvae photos & videos. journal.

Hyalophora cecropia: A Life Cycle Photo Journal.

Part 2: The Caterpillar

Scroll down to see a "Cecropia Moth Caterpillar Growth and Development Photo Journal". View the striking color differences exhibeted within a single instar growth period. Study an indepth slide show showing the ordeal of ecdysis into 5th instar shed.

Eggs of the cecropia moth. They were laid hours after capture of the female moth June 21st 2009. Hatching occured ten days later.

This caterpillar hatched on July 2nd, 2009 about an hour ago. The baby is well on its way to finding its first meal.

(Above) 1st instar two day old cecropia moth caterpillars as seen July 4rth 2009 feeding on silver maple leaves.

To the right are larvae on willow July 6th 2009. The upper left individual is beginning to show signs of orange coloration.

July 7th larvae were spotted preparing to ecdyse into the 2nd instar.

Two cecropia caterpillars: The first to the left is preparing to ecdyse into the 2nd instar while the second has just emerged in the second skin.

One larva a few hours later showing the dramatically different color of the second instar phase of growth. The larva is now 6 days old. (July 8th 2009)

These ten day old 2nd instar caterpillars show different colors from each other. They were both hatched from the same mother. I do not know the reason for this difference. Some larvae showed a darker 2nd instar skin coloration. Might they be color morphs? Note: the far right larva is still in 1st instar.

Before eggs were due to hatch, I did online research looking for advice on what tree species would succussfully host cecropia larvae. Some sources mentioned "silver maple" as a posibility. (Available fruit trees were hard to find and the nearest willow is nearly a mile away.) These caterpillars ate maple leaves but growth was retarded. Growth of those fed maple developed at less than half the rate of willow fed caterpillars. All larvae eating willow were in 2nd instar while those on maple remained in the 1st instar and were much smaller. Feeding all larvae willow seemed to make a big difference in growth and development. Most of the maple-fed larvae readily accepted willow (July 9th 2009)

July 15th 2009 It is evident all 3rd instar larvae now have very similar colors and markings, the earlier variations, possibly due to earlier diet, seem to have been lost with the old skin. All have been on a diet of willow for 6 days..

3rd instar larvae display a wealth of color and contrast following evolutionary form and function! Ecdysis happened this morning. (July 14th 2009)


A few days later (July 17th 2009) The colors within the 3rd instar have deepened.	Greyish toned tubercles now are a beautiful light blue. Background colors are shifting from yellow to a light green.

(July 21st 2009) This caterpillar is still in the 3rd instar. It is growing well and looks about as large as the 4rth instar individual shown below as it looked a day earlier. The original "greyish" tubercles are now a darker blue with a black band in the middle.

Three closeups showing tubercle color deepening and change in 3rd instar cecropia larvae. The photos were taken on the same individual, July 14th, 17th and 21st, 2009. The change from silver/grey, to light blue, turning to a deeper blue with a black band is evident.

Notice how the tubercles in the above pictures seem to be farther apart in each image taken over time. Indeed, the tubercles are increasingly in less and less proximity to each other. The larvae is growing causing the skin to fill out and expand. Somewhat similar to expanding markings or points as when a ballon is blown up with air, so too are the skin highlights enlarging, changing or made noticable.

Questions: Might it be that more colors show up as the skin is stretched out to reveal pigments and patterns previously hidden from view? Would a stretched, thus thinner, skin tend to allow more of the body and/or, at times, new skin within to impact affected color?

Note: Many caterpillars seem to be growing and/or developing at different rates. This was more apparent during the first three instars. As growth progressed the differences seemed to become less pronounced. Pupation started for five of the six larvae between the 10th and 12th of the month. However, the cocoon from one particular fast growing caterpillar was found already completed on August 8th.

This gives a total time as a caterpillar between 37 to 41 days. (This is much shorter than the average 60 day larval time period given in textbooks.)

Here is an old 3rd instar exuvia skin left after ecdysis into 4rth instar. The opening is clearly visable where the larvae exited the old skin.

Cecropia caterpillar newly shed into 4rth instar. The appendages and head are huge. The skin itself, under the right lighting, has a "thicker, folded, baggy" appearance. The ever-growing larvae will stretch the skin to its maximum size, at which time, it will abandon the skin for a larger one. A basic body color change of "more blue/ yellow with less black" continues to express itself. Black markings have dissapeared on the body and claspers. (July 20th 2009)

The same caterpillar as viewed from the top showing the large head. Also, a strikingly beautiful aqua blue color in the upper dorsal region contrasting with the palette of colored tubercles is a nice surprise. The 3rd instar black spots are gone on top as well. (see above comment.)

Above are two 4rth instar cecropia caterpillars as seen July 24rth 2009. The one to the upper right is seen two days after the shed while the larger left larvae ecdysed about 4 days ago.

Notice the more predominant darker green color in one compared to the other, especially in the head, legs and claspers.

To the left is the same larvae as the upper left one seen directly above. This photo shows off the beautiful blue on the back contrasting with the blue, red and yellow tubercles. When positioned in the more comfortable preferred posture as seen above, the colors are more subdued and camouflaged. The caterpillar is usually shaded from intense sunlight by the canopy of foliage above. Colors we find more appealing to our sensibilities only become apparent when the larvae is in bright or direct sunlight. This is detrimental to its health and also increases exposure to predators. The lighter blue colored upperparts true function is to hide the insect from being spotted from one looking upwards towards bright sunlit foliage thus being presented with the larvae's back dorsal area from below, (as positioned above).

Above: This late 4rth instar caterpillar is shown one day before it began the process of ecdysis into the fifth and last skin. Compare how it looks now, July 28th 2009, with how it appeared 8 days ago, July 20th.

Of Ordeal And Patience:

A 4rth instar caterpillar is preparing to ecdyse into it's 5th and last skin as a larvae. A long wait and arduous labor for the caterpillar lies ahead. This is a difficult time lasting a couple days. I have been watching closely hoping to observe and photograph the actual event. ( I missed one yesterday.) This larvae assumed the present position sometime in the late afternoon of July 28th.

The close watch began the morning of July 29th. and lasted all day into the morning of July 30th, During this 27 hour time span, from 8:00AM until 11:00AM the next day, the larvae exhibeted periodic stretching, spasmodic contractions and occasional violent twitching. It seemed a long and arduous struggle was taking place with no immediate discernable result. When, finally, the long wait was over the larvae proceeded to break free of the confining skin and slowly move itself forwards while working the skin backwards. I got an ecdysis photo sequence but the larvae had shifted position so most pictures were partly out of focus. The left image catches a tittle of the drama of what I saw.

Below is a 41 frame photo sequence showing details of ecdydsis skin shed into 5th instar. To view a larger picture click on a thumbnail image. To view as a slideshow sequence click on the upper left photo and then use the navigation tools below each full size image to advance to the next frame. Note: clicking on any of the 15 thumbnails will bring up the 41 image slideshow.

(Yes, patience can be rewarded. A third try yielded the results shown below.) August 1st, 2009

Here is a video showing ecdysis into 5th instar in a different way.

Above: July 28th 2009 Here the caterpillar is recycling as it eats the discarded old skin. Again, just as in the fresh 4rth instar skin, the appendages are huge. The larvae shows rapid growth and eats prodigiously. I need to go get more willow leaves!

Left: Soon it will be time to clean up the frass once again!

Above are two caterpillars. One just shed a day ago into the 5th and final instar, The other is still in the 4rth skin. Can you tell which is which? Hint: look at the head sizes and how "loose" the skin looks in one and how "filled out" and "stretched" it is in the other. It's the same pattern of growth as seen earlier in the previous shed. (July 28, 2009

Two views of a caterpillar as it looks at about 5 days after its 5th instar shed. It is GROWING! Notice the color difference. The top shows an irridescent pale bluish sheen in direct light. ( August 4rth, 2009)

A cecropia caterpillar is seen begiinning to draw pieces of vegetation together and glueing them with strands of silk. The process continues as the silken framework of the future cocoon, reinforced by leaves and twigs, begins to take shape. (August 9th, 2009)

See how the caterpillar builds the cocoon. . watch the transition from the picture above to the photo below. click here or on the cocoon below.