Monarch Butterfly Development

Daily photos of every stage of development from egg to adult, including caterpillar and chrysalis. There is also a chart with a quantitative analysis of caterpillar growth. Please see the About page for more information and commentary.
Day 1: July 23, 2020 4:23 PM This photo was taken about 5.5 hours after a female monarch butterfly visited milkweed plants in my yard and presumably laid this egg, which was the only one I...
Day 1: July 23, 2020 4:23 PM
This photo was taken about 5.5 hours after a female monarch butterfly visited milkweed plants in my yard and presumably laid this egg, which was the only one I…
Day 2: July 24, 2020 9:35 AM There is no obvious change from the previous day.
Day 2: July 24, 2020 9:35 AM
There is no obvious change from the previous day.
Day 3: July 25, 2020 8:56 AM There is no obvious change from the previous day.
Day 3: July 25, 2020 8:56 AM
There is no obvious change from the previous day.
Day 4: July 26, 2020 9:56 AM The egg is starting to hatch.
Day 4: July 26, 2020 9:56 AM
The egg is starting to hatch.
Day 4: July 26, 2020 4:04 PM About 6 hours after hatching began, a tiny caterpillar has emerged. There is no sign of the egg shell, which was probably eaten by the caterpillar. At this...
Day 4: July 26, 2020 4:04 PM
About 6 hours after hatching began, a tiny caterpillar has emerged. There is no sign of the egg shell, which was probably eaten by the caterpillar. At this…
Day 5: July 27, 2020 9:30 AM The caterpillar has already grown considerably and is starting to show the colored bands typical of monarch butterfly caterpillars. Length=3.57 mm. Width=0.76...
Day 5: July 27, 2020 9:30 AM
The caterpillar has already grown considerably and is starting to show the colored bands typical of monarch butterfly caterpillars. Length=3.57 mm. Width=0.76…
Day 6: July 28, 2020 10:00 AM Length=5.56 mm. Width=1.18 mm. Volume=6.06 cubic mm.
Day 6: July 28, 2020 10:00 AM
Length=5.56 mm. Width=1.18 mm. Volume=6.06 cubic mm.
Day 7: July 29, 2020 9:27 AM Length=6.60 mm. Width=1.29 mm. Volume=8.61 cubic mm.
Day 7: July 29, 2020 9:27 AM
Length=6.60 mm. Width=1.29 mm. Volume=8.61 cubic mm.
Day 8: July 30, 2020 8:43 AM Length=9.01 mm. Width=2.17 mm. Volume=33.3 cubic mm.
Day 8: July 30, 2020 8:43 AM
Length=9.01 mm. Width=2.17 mm. Volume=33.3 cubic mm.
Day 9: July 31, 2020 8:24 AM Length=8.29 mm. Width=1.82 mm. Volume=21.5 cubic mm.
Day 9: July 31, 2020 8:24 AM
Length=8.29 mm. Width=1.82 mm. Volume=21.5 cubic mm.
Day 10: August 1, 2020 8:34 AM Length=14.20 mm. Width=2.71 mm. Volume=82.2 cubic mm.
Day 10: August 1, 2020 8:34 AM
Length=14.20 mm. Width=2.71 mm. Volume=82.2 cubic mm.
Day 11: August 2, 2020 9:26 AM Length=16.6 mm. Width=2.82 mm. Volume=104 cubic mm.
Day 11: August 2, 2020 9:26 AM
Length=16.6 mm. Width=2.82 mm. Volume=104 cubic mm.
Day 12: August 3, 2020 9:10 AM Length=26.2 mm. Width=4.49. Volume=415 cubic mm.
Day 12: August 3, 2020 9:10 AM
Length=26.2 mm. Width=4.49. Volume=415 cubic mm.
Day 13: August 4, 2020 9:04 AM Length=20.8 mm. Width=4.79 mm. Volume=374 cubic mm.
Day 13: August 4, 2020 9:04 AM
Length=20.8 mm. Width=4.79 mm. Volume=374 cubic mm.
Day 14: August 5, 2020 8:45 AM Length=28.6 mm. Width=5.21 mm. Volume=608 cubic mm.
Day 14: August 5, 2020 8:45 AM
Length=28.6 mm. Width=5.21 mm. Volume=608 cubic mm.
Day 15: August 6, 2020 9:00 AM Length=39.7 mm. Width=6.77 mm. Volume=1429 cubic mm.
Day 15: August 6, 2020 9:00 AM
Length=39.7 mm. Width=6.77 mm. Volume=1429 cubic mm.
Day 16: August 7, 2020 9:19 AM Length=48.1 mm. Width=8.81 mm. Volume=2932 cubic mm.
Day 16: August 7, 2020 9:19 AM
Length=48.1 mm. Width=8.81 mm. Volume=2932 cubic mm.
Day 17: August 8, 2020 8:45 AM The caterpillar has stopped feeding, climbed to the top of the cage, and attached itself. It is now a prepupa.
Day 17: August 8, 2020 8:45 AM
The caterpillar has stopped feeding, climbed to the top of the cage, and attached itself. It is now a prepupa.
Day 17: August 8, 2020 2:02 PM Pupation has occurred! A wing anlage is visible at the right side of the chrysalis, although it was not visible in the caterpillar or prepupa. It must have been...
Day 17: August 8, 2020 2:02 PM
Pupation has occurred! A wing anlage is visible at the right side of the chrysalis, although it was not visible in the caterpillar or prepupa. It must have…
Day 18: August 9, 2020 6:41 AM The chrysalis looks about the same as when pupation occurred.
Day 18: August 9, 2020 6:41 AM
The chrysalis looks about the same as when pupation occurred.