We’ve nurtured three monarch butterfly caterpillars through their final bulking up and into the chrysalis stage and it’s been fascinating watching it all – one of them attached itself to the handle of a teapot in the kitchen so we got an up-close view of proceedings.
We moved the caterpillars inside because of wasp predation which doesn’t seem to be the complete extermination it was last year, as a few caterpillars have been making it through to chrysalis without our help. Wasp predation should finish at about the end of February.
To find out more about monarch butterflies, visit the Monarch Butterfly NZ Trust website.
Eggs on a swan plant leaf. Hatching will be 4-8 days, depending on temperatures. The egg will turn grey when it’s ready to hatch and a black dot (head) will be visible. Females lay up to 400 eggs at the rate of about 40 a day. Photo: Sandra Simpson
A tiny, very hungry, caterpillar … Photo: Sandra Simpson
… turns into a large, very hungry caterpillar. In 2-3 weeks it grows to 2700 times its birth weight! To accommodate this growth it moults 5 times. Photo: Sandra Simpson
Now we follow the story through photos of a single caterpillar …
When the caterpillar weighs about 1.5g it sets off to find somewhere to hang its chrysalis – in this case the handle of a teapot! Rear ‘protolegs’ attach to a silk ‘mat’ it’s secreted and the caterpillar begins turning itself inside out to form the chrysalis, with plenty of wriggling involved. The process took no more than 10 minutes. Photo: Sandra Simpson
With a final wriggle the chrysalis is complete and the black bit left sticking out the top (we wondered what was going to happen to it) falls off – excess skin. The chrysalis kept wriggling for a little bit. Within 2 days what’s left of the caterpillar becomes a pupa. No one yet knows what the beautiful gold spots are for. Photo: Sandra Simpson
It takes about 10 days for hatching – just before the butterfly emerges the chrysalis turns black (still with gold markings) and the butterfly inside becomes visible. Photo: Sandra Simpson
The newly hatched butterfly (a male) rests quietly near what’s left of the papery chrysalis. When it emerges it has an abdomen full of fluid that pumps into its wings before it can fly. During summer monarchs live for 60-70 days. Photo: Sandra Simpson
Many thanks to the University of Waikato’s monarch butterfly life cycle page for extra information. This overview page about monarch butterflies is also worth reading.