Monday, February 21, 2011

Checkerspots

In case you were wondering, the title photo of my blog is of mudpuddling snowberry checkerspots, Euphydryas colon, in the hills above Reecer Creek Canyon north of Ellensburg, WA.   This species was formerly known as Euphydryas chalcedona, and the subspecies colon was only attributed to the populations in southwestern Washington into western Oregon (E. chalcedona colon).  Recent research however, has placed them back into a full species with a new common name ("snowberry" instead of "chalcedon" or "variable"), and those populations in SW WA and OR are now known as E. colon colon.  The populations found in central WA, such as the individuals in the photo, are referred to as the central WA cascades segregate of E. colon (see BofA page), and are currently being studied to determine how they should be named (one or multiple subspecies, or an entirely new species).
Life history - snowberry checkerspots overwinter (diapause) as early-instar larvae, in tent-caterpillar-like webs they spin among loose rocks or leaf litter below their host plants (species of penstemon and snowberry). The larvae emerge in the spring and begin feeding on the host leaves, and pupate in late spring. The adults emerge about ten days later, with a peak flight (highest numbers) usually in July.  Adults nectar on flowers, and in the Reecer Creek area seem to prefer Eriogonum species and yarrow.  After mating, the females lay their eggs in clusters on the leaves of their chosen host plant.  The adults die about ten days after emerging from the chrysalis, leaving the newly emerged larvae to continue the cycle.
Female ovipositing on penstemon
Early-instar larvae (approx. 10mm in length) 
Late-instar larvae (approx. 25mm)
Larvae preparing to pupate; one pupa/chrysalis on the right
chrysalis
Adult ready to emerge from pupa - you can see the dark color of the body and some of the spots

Freshly-emerged adult (red stain is a fluid released when adults emerge)
Adult pumping its wings
Adult with wings fully inflated
Adults on yarrow (front) and buckwheat (back) 
Adults mudpuddling (same location as title photo)

2 comments:

  1. Those are really beautiful pictures. I love your blogspot. Good job Ace!

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  2. Cait, I got on again. Love your new material and the bird pix and your others about butterflies. Keep up the good work. Nancy H who seems to be registered as John F. H. That's okay. If I comment I will sign as Nancy. The liver Brittany head works for me as well.

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