Finding Utah Butterflies-->Yellow Sulphur (Colias philodice eriphyle)

Overview:

The Yellow (or Clouded) Sulphur can be found flying in alfalfa fields from mid April to October. Because caterpillars of this buttefly feed on alfalfa, its numbers tend to explode in these alfalfa fields with successive generations during the summer months. One of the challenges of collecting Yellow Sulphurs is that these fields are usually on private property where owners might not appreciate people trampling through their hay. However, because this butterfly is so common here, it is usually not too difficult to find adult butterflies in adjacent roadways and neighborhoods.

Although adult butterflies are normally yellow, from time to time, you will find an albinic (white) female of this butterfly. An example is pictured in the lower right hand corner of the photo plate above. There are many species of sulphur butterflies that have albinic females.

Specific Localities:

Any alfalfa field in Utah that has not been sprayed with insectiside.

Flight Periods:

April through October. 

Raising Caterpillars Resources:

Yellow Sulphur caterpillars rest right on the vein of the upperside of alfalfa leaves (Medicago sativa). Ironically, finding caterpillars in alfalfa fields can be a long and arduous task simply because of how much plant there is; notwithstanding the fact that any alfalfa field could have tens of thousands of caterpillars during the summer months even when the butteflies are on wing. A nice tactic to look for caterpillars might be to look for isolated, individual plants growing incidentally along nearby roads. Females of this butterfly will also lay eggs on sweet clover (Melilotus officinale); a weed that also grows along roadways and ditches. Sweet clover has yellow flowers whereas alfalfa has purple flowers.

Raising Butterflies: http://www.raisingbutterflies.org/colias-philodice-eriphyle/ 

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