Euphydryas anicia wecoeut

Photo Life History:  Euphydryas anicia wecoeut

Habitat:  Pinyon Juniper; Canyonlands, badlands, swells, and reefs within the Colorado Plateau region of  Eastern, Northeastern, Central and Southern Utah as well as Eastern Colorado.

Host Plants:  Castilleja chromosa

Suitable Lab Host Plants:  Most any species of paintbrush (Castilleja) or Penstemon.

Caring for Live Female Butterflies:  Feed females regularly.

Methods of Female Oviposition:  Portable Cages.

How to Find Eggs:  Females lay eggs in large clutches on host plants.  Look on the ventral side of leaves towards the lower portion of the host plant.

How to Hatch Eggs:  Consolidate eggs into one container.

How to Find Caterpillars in the Field:  To find gregarious pre-diapause larvae, look for webbing (almost like a spider web) on the plant.  Post-diapause larvae can be found either resting at the base of the host, off the plant altogether, or feeding on host plant flowers or leaves .  Keep in mind that once you find one post-diapause larva, start looking closer in that general area as post-diapause larvae disperse roughly within 100 feet (or so) from where the pre-diapause larvae fed.  Euphydryas anicia larvae can begin feeding on its host plants as soon as the host breaks ground in the spring.

Caterpillar setups:  For pre-diapause larvae, I recommend using the open terrariums or open bucket technique.  Overcrowding is not generally an issue since larvae are gregarious in nature.  For lab rearing in the late spring, I like finding Penstemon eatonii plants that have already flowered and have cupped leaves.  I place cut-out clutches of eggs on the leaves of Penstemon cuttings of these plants and let the eggs hatch and set up a webbed nest/feeding station right on the plant.  (Handling hatchling first instar larvae is not necessary.)  For post-diapause larvae, see Post-Hibernation Strategies below.

Larva to Pupa:  Caterpillar silks to leaf or twig; creates and attaches cremaster; hanging as a J before pupating.

Number of Broods per Year: 1

Overwintering Stage:  Third or Fourth Instar Larva.  

Overwintering Strategies: Your Own Backyard.

Post-Hibernation Strategies: When you feed post-diapause larvae after overwintering, if you're only rearing a few caterpillars, I highly recommend isolating caterpillars from sibling caterpillars using the twin cup method (or similar) in order to avoid re-diapause--an extremely common situation with checkerspots.  (See this video for more information on the twin cup method.)  Jacque Wolfe recommends exposing post-diapause larvae to cold overnight temperatures.

Avoiding Diapause Techniques:  Not applicable.

Disease Prevention:  For post-diapause larvase, change out host plant and remove frass every two to three days using the twin cup method.

Emergence:  Emergence Container

Field Notes: Populations of this butterfly are scattered throughout the San Rafael Region of Utah; east towards the East Tavaputs Plateau and North towards the Uinta Basin.  Many populations use Castilleja chromosa which can grow spotty and intermittent throughout this region.  With this butterfly, it is always recommended that you find populations of adults before seeking immatures.