i realize that it looks like the sand people got us in the end, since we disappeared in the middle of death valley and have posted nothing in the intervening [wince] nearly three months.  oops.  all i can say is, my laptop died the blue-screen death, locking the remaining trip photos inside until recently, and with it perished my photo-processing software, so visual aids to the posts i’ve had in mind have been a little paralyzed.  add to that the fact that the pebbles and i will be joined by a small new human in june, and a semester-start with 1500 first-year students, and you get the idea — not as an excuse, but by way of an explanation.

but it’s time to begin 2012, however belatedly, as i have intended all along — with butterflies!

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in our back yard, we have a large swan plant (Asclepias physocarpa), a species of milkweed that has become well established in nz, probably by dint of playing host to the beloved monarch butterfly, Danaus plexippus.  while neither is native, monarchs most likely colonized nz under their own steam, and were later assisted in becoming established by the increasing popularity of swan plants in gardens.  both seem to be well tolerated although i can’t find much information on the weed status of Asclepias.

in any case, we had some caterpillars last year, but only a few made it to adulthood due to a combination of wasp predation, aphid infestations and probably also a very fat praying mantis i discovered lurking under one of the leaves late in the season.  so this year, when i noticed tiny caterpillars starting to munch the swan leaves, i decided to bring a few inside for observation once they got larger, and hopefully save them from predation while enjoying some living-room science.  i selected a few nice fat ones a few weeks later, as well as some of the earliest chrysalises, and set them up in a small terrarium.

over the next few days, the ones i had brought in pupated obligingly, although i was amazed at the speed with which it happened — so quickly that i didn’t get a chance to photograph the metamorphosis, although a nice series can be seen here.  one in particular took up the telltale j-posture one evening, was still in it the following evening, and then had already changed into its smooth green chrysalis when i checked back an hour later, although still somewhat elongated and contracting gently.  i had not realized previously that the pupa forms inside the caterpillar skin; the latter splits open and peels back, falling as a tiny shriveled husk once the chrysalis emerges; this was one of several fascinating revelations i had while watching the process.  another was the gorgeous detail of the chrysalis structure — edged in black and iridescent gold, with the patterns of the future wings already visible as soon as the chryalis forms.  (apparently it’s not uncommon for pre-schoolers observing the monarch life cycle in new zealand to mistake the chrysalises for green lollies… an error i don’t imagine is often made more than once by any given child.  EW)

about two weeks later, my first butterfly hatched, again with astonishing speed: the chrysalis turned black and transparent overnight, was still whole first thing in the morning, and half an hour later had a trembling butterfly clinging to its emtpy membrane as the wings slowly filled.  we kept it inside until the wings appeared stiff and finished and the butterfly began to climb, and then took it outside to make its maiden flight and contribute to the next generation.  the remaining three followed over the next week, allowing me a good look at them as they hung to dry, but never actually emerging while i watched.  at last check, the swan plant still had new caterpillars appearing on it, although it is now mostly stem and strange seed pods, the voracious first generation having mostly decimated its leaves and the aphids busily finishing the rest.  but hopefully our monarch population will return each year, so we can share the amazing details of their transformations with our own next generation when it joins us.  :)

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