Hummingbird and Butterfly Gardening: DAILY PICTURES # 110, 1 by Sheila_FW

Sheila_FW wrote:
Since we are speaking about losses, these are some of my pictures from past experiences. The first two were the same Chrysalis, and maybe the parasite in the third. The fourth has an arrow pointing to the hole where a parasite emerged from a Swallowtail's Chrysalis.

The last is an entire blackened chrysalis, and I seem to remember I didn't get viable butterfly from this one. What is it that caused this Dale, the NPV?