Taylor’s checkerspot butterflies enter chrysalis: a key milestone in captive breeding

Every spring, a quiet yet extraordinary transformation unfolds in our conservation facility. After weeks of care and feeding, the Taylor’s checkerspot caterpillars (Euphydryas editha taylori) in our breeding program have all entered the chrysalis stage—a critical developmental milestone in our work to prevent the extinction of this endangered butterfly.

Earlier this spring, our overwintered caterpillars emerged from diapause (a dormant phase) in response to increasing daylight and warmth. Over several weeks, they resumed feeding on their primary host plant, Plantago lanceolata (ribwort plantain), growing rapidly through their final instars and building the energy stores required for metamorphosis.

Flash forward to May, all of our caterpillars have entered pupation. Each forms a silk pad and suspends itself in a characteristic “J” shape before shedding its skin and forming a chrysalis. Within this casing, a complex transformation takes place—tissues reorganize to form the adult butterfly’s wings, body, and organs in a process that will last roughly two to three weeks.

This pupal stage is one of the most delicate in the butterfly’s life cycle, and our team closely monitors temperature, humidity, and health throughout. If development proceeds as expected, we anticipate the first adults to emerge by late May or early June.

Unlike wild individuals, the butterflies emerging in our facility will not be released. Instead, they will form part of a carefully managed captive population used to support ongoing breeding and genetic conservation efforts. These adults will help us maintain a robust and diverse captive lineage—an essential foundation for long-term recovery and, potentially, future reintroductions.

Each chrysalis is a small capsule of hope and resilience. With the continued support of our partners and community, we’re working to ensure that this remarkable species is not lost to extinction.