Found a Painted Lady Chrysalis

We found a Painted Lady chrysalis (Vanessa cardui) on the same thistle that we collected the two caterpillars before at Tilden Regional Park (Berkeley, CA).

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This morning when we went to Tilden, the weather was very bad for finding butterflies. It was below 60 degrees, very cloudy, and there were occasional sprinkles. On the trail, the only thing we could really do was search for caterpillars or eggs. 

There are a lot of potential lepidopteran host plants at Tilden and the habitat is great since there is a creek and a lake to provide for riparian species. For trees, there are tons of willow (Salix), coast live oak (Quercus agrifolia), eucalyptus (Eucalyptus) and some conifers among a number of other trees. As for shrubs and vines, there is plenty of bramble (Rubus ursinus), stinging nettle (Urtica dioica), milk thistles (Silybum marianum), plantain (Plantago), and a whole bunch of other small plants.

What interested us most were the nettles and thistles which are favorite hosts of the Red Admiral (Vanessa atalanta) and Painted Lady (Vanessa cardui), respectively. There were the most nettles near the beginning of the trail but it was so dense and shaded that it would hard to find anything; and there presumably wasn't any because it all seemed rather uneaten with no leaf nests or frass as evidence for caterpillar inhabitants. There were a lot of thistle growing along the entirety of the trail, much of which was mature and flowering -- perfect nectar sources for butterflies had the weather been better. Last time we found two Painted Lady caterpillars on a rather isolated plant near the beginning of the trail that was covered in heaps of frass trapped in silk. 

After walking for half an hour and investigating every thistle plant we spotted, we only found two groups of plants that had any evidence of caterpillars: one was the plant from before and the other was a group of huge ones growing much further down the trail. Neither seemed to have any current inhabitants (the nests can stay for months after the caterpillar leaves if nothing destroys it). But when we took a closer look at the first plant, we noticed a Painted Lady chrysalis hidden deep within the thorny thickets at the base of a plant. 

Upon closer inspection, this chrysalis seems close to emerging. The fifth instar caterpillar that we found on this plant on 7/9 had already long pupated and emerged yesterday so this does make sense if they are in the same clutch; the outdoor temperatures are generally lower than indoor which hastened the growth rate and development of our caterpillar. If it is a male, than perhaps we can attempt to have them mate in captivity as we had our Gulf Fritillaries (Augraulis vanillae) do today. 

- Brian