Journal archives for February 2020

February 13, 2020

Calephelis Metalmark ID Notes For Texas (Fatal, Rounded, Rawson's & Little)

Fatal Metalmark (ssp. australis) Notes: Silver Bar 1 & 2 in postmedian band on forewing are evenly aligned (e.g. single-looped) & Bar 3 & 4 are aligned about evenly with them or slightly above (e.g. not bulging). Black Bar 1 to 4 in postmedian band on forewing follow a similar pattern except Bar 3 is offset significantly higher above them. Postmedian band of hindwing (area between silver & black lines) is open and generally pale. A fresh Fatal usually has 3 prominent white fringe-marks on its FW (Each end & the middle) and occasionally 2 to 4 less distinct white fringe-marks on its HW. [Rounded- often lacks prominent white fringe-marks, but can have 2 on its FW (Each end) & in rarer cases additional ones on FW & HW; Rawson's- Its FW usually has 2 semi-prominent white fringe-marks (Each end) & often 1 or more smaller white fringe-marks in the middle. Each HW often has 3 to 4 small white fringe-marks]. See Miscellaneous Section and Foot Note (1) for additional information.

Rounded Metalmark Notes: Silver Bar 1 and 3 in postmedian band on forewing are roughly evenly aligned & Bar 2 is offset below them (e.g. double-looped & bulging). Black Bar 1 to 3 in postmedian band on forewing usually roughly replicates the pattern of the silver bars or occasionally forms a step-like pattern with an upward slant. Black Bar 3, consequently, in postmedian band is usually even or offset higher to Bar 1 (In Fatal Bar 3 is offset significantly higher than Bar 1. In Rawson's Bar 3 is typically about even to Bar 1). Postmedian band of hindwing (area between silver & black lines) generally, but not always, has a narrowish section near abdomen. Fresh individuals often lack prominent white fringe-marks, but occasionally do have one on the front end or both ends of FW. In rarer instances they can also have a weak middle white fringe-mark on FW and additional white fringe-marks on HW. See also the below note on range differences between Rawson’s and Rounded.

Rawson's Metalmark Notes: Silver Bar 1 and 3 in postmedian band on forewing are roughly evenly aligned & Bar 2 is slightly offset below them (e.g. mildly double-looped). Black Bar 1 to 3 in postmedian band on forewing roughly replicate the pattern of the silver bars. Black Bar 3 in postmedian band is about 80% of time roughly even to Bar 1 and 20% of time significantly higher. (In Rounded Bar 3 is even or higher to Bar 1. In Fatal Bar 3 is always offset significantly higher than Bar 1). Postmedian band of hindwing usually fairly open without a narrowish section near abdomen that Rounded often possesses. A fresh Rawson's usually has 2 semi-prominent white fringe-marks on forewing (Each end) & frequently, but not always, 1 or more smaller white fringe-marks in the middle. Each HW often has 3 to 4 small white check-marks. See also the below “Range Note” for Rawson’s and Rounded.

Little Metalmark (C. virginiensis) is very rare in Texas. It is found primarily outside of Texas in the southeastern coastal states (Louisiana to North Carolina). A few have been reported, however, within Texas in the Big Thicket Preserve area northeast of Houston. No other species of metalmark falls within its range. Little Metalmark looks somewhat similar to the three other Calephelis species in Texas, but differs in never having a darkened median band or white fringe-marks on its wings. It likes open pine woods and wet prairies. Host plants are Yellow Thistle (Cirsium horridulum) and Vanillaleaf (Carphephorus odoratissimus).


Miscellaneous & Foot Notes

Range Note: Differences between Rounded and Rawson's are minimal. Best way most of the time to differentiate is probably by using their range maps. They overlap only in Central Texas (Austin/San Antonio). Rawson’s is found mainly 1) on the Edwards Plateau in rocky and riparian canyons and 2) in West Texas within a few canyons normally above 4,500’ (e.g. Big Bend N.P. & Davis Mtns). Rounded is found generally in more open and level terrain from Austin southward (excluding hill country) downward to the coast and South Texas. Fatal coexists in both their ranges.

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 a closed underwing.

Host Plant Notes: Fatal- Texas Virgin's Bower (aka Old Man's Beard, Clematis drummondii) & Willow Baccharis (Baccharis salicina). Rounded- Siam Weed (Chromolaena odorata), Pink Thoroughwort (Fleischmannia incarnata) & probably other mistflowers (e.g. Conoclinium betonicifolium, & Eupatorium serotinum). Rawson's- Shrubby Boneset (Ageratina havanensis) & probably Palmleaf Thoroughwort (Conoclinium dissectum).

Reliability of ID Notes: Information in the guidebooks for identifying Calephelis present 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 often 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 color, median band darkness, wing shape, & submarginal spot size on hindwing I examined, but did not find very helpful. I tested my ID notes on over 1,000 photographed specimens. They appear to be reasonably accurate, especially, when one is able to get confirmation with at least two of a species’ special features. Comments and corrections are welcomed. I also have journal posts in iNaturalist on identifying Calephelis in Arizona and California.

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

Foot Notes
(1) Many Fatals in Arizona and California have their silver and/or black bar pattern in their PM band on FW double-looped (Bar 2 lower than Bar 1 & 3). I have found no evidence this form is present in Texas. A Fatal of any of the three subspecies likely always has Black Bar 3 elevated over Black Bar 1 in its PM band on FW.

(2) Calephelis is a Greek word meaning “the beautiful deceiver”. This name may have been given because the butterfly was judged beautiful, but classification to a species level within the genus problematic due to their close similarity.

Posted on February 13, 2020 12:38 PM by sfrue sfrue | 0 comments | Leave a comment


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