Journal archives for March 2021

March 20, 2021

Calephelis Metalmark ID Notes for California (Fatal & Wright’s)


Differences between Wright’s (C. wrighti) and Fatal (C. nemesis ssp. dammersi) in California

1] Location/Habitat: Fatal- Found in southeastern California mainly in riparian areas along the coast generally below 800’ elevation. Butterfly’s range closely follows the range of its host plants Brittlebush (Encelia californica) and Baccharis glutinosa. Wright’s- Found in southeastern California mainly in desert canyons and gullies generally above 800’ elevation. Butterfly’s range closely follows the range of its host plant, Sweetbush (Bebbia juncea).

2] Median band darkness: Fatal- Light to dark. Wright’s- None.

3] Upper-wing color: Fatal- Brownish, orangish brown, or/& reddish brown. Colors are often mixed & can vary from light to dark. Upper-wing color is never a pure uniform orange. Wright's- Orange to reddish brown. Upper-wing color is almost always uniform. A few Wright’s possess a dark shading on the leading edge of the forewing and/or the inner part of their wings adjacent to the body. This shading can create a somewhat bi-color look.

4] Black Post-Median band line pattern on Forewing: Fatal- Bar 1 & 2 about even with each other and Bar 3 is offset significantly higher above them. Wright’s- Most the time (75% +/-) Bar 1 and 3 are roughly even with each other and Bar 2 is offset significantly below them. Occasionally (25% +/-) Bar 1 to 3 have a pattern similar to Fatal or possess a seemingly random pattern (See also the below Bar Alignment Note)

Miscellaneous & Reference Info.

Bar Alignment Note: To interpret the bar alignment pattern on an extended upper forewing, an imaginary line formed by connecting its first 3 black submarginal dots on its forewing should be held approximately in a horizontal position to the identifier. Bars will often have an irregular shape (e.g. a slanted line or two joined slanted lines). Height for these bars should be taken at the center of the cell they are within. The black submarginal dots located above bars can be used as reference as they are situated at cell center. Bar alignment pattern is usually clearer on the closed underwing.

Reliability of ID Notes: Information in the guidebooks for identifying Calephelis in the southwestern United States I have often found confusing and occasionally inaccurate. This arises in part from the three subspecies of Fatal in the United States (ssp. australis in Texas, ssp. nemesis in Arizona, & ssp. dammersi in California) generally being treated as having identical features when in fact differences exist.

In deriving the above notes, data from Butterflies of America was first analyzed for unique species traits. Identifications from this source are largely made by academic professionals who may perform genitalia or DNA analysis. Interesting traits from it were then tested on other data such as iNaturalist to see if they held. If they did not hold, an attempt was made to find out why (e.g. misidentification, variability, etc.). Wing shape, white fringe-marks, and submarginal spot size on hindwing were not found very helpful. The above ID notes were found to be reasonably accurate, especially, when one is able to get confirmation with at least two of a species’ special features. I have additional journal posts in iNaturalist on identifying Calephelis in Texas and Arizona. Comments and corrections are welcomed.

Main Reference Sources:
"A Swift Guide to Butterflies of North America" (2017) by Glassberg
Personal observations & readings from BugGuide, iNaturalist, etc.

Posted on March 20, 2021 04:04 PM by sfrue sfrue | 0 comments | Leave a comment


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