Editing Papilio polyxenes (section)

===Caterpillar and chrysalis===
This caterpillar absorbs toxins from the host plants, and therefore tastes poor to bird predators.<ref name=":0" /> The black swallowtail caterpillar has an orange "forked gland", called the [[osmeterium]]. When in danger, the osmeterium, which looks like a [[snake]]'s tongue, everts and releases a foul smell to repel predators.<ref name=":0" />
[[File:Black Swallowtail Chrysalis by sdetwiler at wikimedia commons.jpg|thumb|Black swallowtail chrysalis, brown color morph]]

The [[pupa]]e may be green or brown, but not depending on surroundings or the background on which they have pupated. The color of the [[Pupa#Chrysalis|chrysalis]] is determined by a local genetic balance that ensures the majority of pupae will blend in.<ref name=CBIF>[http://www.cbif.gc.ca/spp_pages/butterflies/species/BlackSwallowtail_e.php Black Swallowtail], Butterflies of Canada</ref> A section of the green pupae will turn a much darker green at the very end of the pupae stage. This color change occurs a few hours to a full day before hatching.<ref name=CBIF/> Unusually, this butterfly's chrysalis is girdled with a loop, with its feet attached to the silk pad, which helps the butterfly to unfold its very large wings when crawling out.<ref name=ipr>{{cite web|title=Horticulture Friday, live at Reiman Gardens|url=http://iowapublicradio.org/programs/talk-iowa|website=Iowa Public Radio, Talk of Iowa|publisher=IPR|accessdate=27 March 2015|date=27 March 2015}}</ref>