ID Guide 3 (cont'd): Thin-banded Lichen Moth and Similar Species in Texas

Many of the Cisthene lichen moths are similar in general pattern but quite variable within each species. This led Knowlton (1967) in his "Revision" of the genus to provide limited information on discrimination by pattern and to rely heavily on genitalic differences for species separation. While that might be justifiable from a technical standpoint, it left the identification of specimens and photos by non-specialists at a great disadvantage for 50 years. Along with Knowlton's brief notes, much useful information on identification by color patterns has been previously published but it is widely scattered in the literature (e.g., Neumoegen & Dyar 1893; Holland 1903; Dyar 1904; Covell 1984; Powell & Opler 2009; Beadle & Leckie 2012). That said, I have studied sets of verified images and specimens (e.g., Barcoding of Life Data System, BOLD) to elucidate additional helpful hints to separate several species. I searched Moth Photographers Group (MPG), BugGuide (BG), Butterflies and Moths of North America (BAMONA), and other online sites for images and distributional data. I reviewed all iNaturalist observations (as of 9/26/2017) of Cisthene moths in the U.S. east of the Rocky Mountains. None of these sources is error-free, thus I relied heavily on barcoded specimens (BOLD) and those vetted by genitalic examination (e.g., Knowlton 1967) and recognized experts to assess color patterns.

In the previous two journal entries, I provided an artificial key to the 12 Texas species of the genus Cisthene. In this third part of this series, I offer the first of a set of descriptions of species, emphasizing those aspects which are most useful for identifying each in the field or from photographs and descriminating them from similar species. I review the range of each species as presently known and offer any habitat notes that I can recognize. The reader is refered to that previous key for more images of the species covered here.

For convenience, I am starting with Thin-banded Lichen Moth, the most widespread species in Texas, most numerous in Central Texas, and the one with which several other species are likely to be confused. In this journal entry, I include notes on these species: Thin-banded (including the Arizona population known as C. tenuifascia schwarziorum or "Schwarz's Lichen Moth"), One-banded, Barnes', Martin's, and Tamaulipan Lichen Moths. Common names are from Covell (1984), Beadle & Leckie (2012), and BAMONA (2017); I offered a few suggestions for common names in the previous key to facilitate communication among non-specialists.

Acknowlegments: I am grateful to @alexwild (Univ. of Texas Insect Collection), @hughmcguinness (who checked specimens at U.S. National Museum), Ed Knudson (Texas Lepidoptera Survey), Steven Nanz and Bob Patterson (Moth Photographer's Group), Valerie Bugh (Lady Bird Johnson Wildflower Center), @beschwar, @dianaterryhibbitts, @jaykeller, @leehoy, @ptexis, @rjnjr, @royaltyler, Ann Hendrickson, and Arlo Pelegrin for useful discussions, and to the several photographers cited below and in previous parts of this ID Guide 3, and all of the iNaturalists who have uploaded observations of Cisthene moths.

Thin-banded Lichen Moth (Cisthene tenuifascia)
MPG: http://mothphotographersgroup.msstate.edu/species.php?hodges=8066 (but see note below)
BG: http://bugguide.net/node/view/90495
Cisthene tenuifascia TX5451615-Lasley 100x2 Cisthene tenuifascia TX3028159-Lasley 100x2
Figures 1 & 2. Variation in the Thin-banded Lichen Moth in Texas. Ph. @greglasley, used by permission.

Range. Thin-banded Lichen Moth ranges from Arizona ("Schwarz's" Lichen Moth) east across the southeastern U.S. to Florida, as far north as southern Kansas, Kentucky, and North Carolina, ranging up the Atlantic Coast (rarely) to New Jersey (Knowlton 1967, Muller 1976, and MPG); it is also found in northeast Mexico (Coahuila, Nuevo Leon). The species is apparently not common east of Texas as there are presently no confirmed iNaturalist or BugGuide records in that region, but Knowlton (1967) examined specimens from several southeastern states. There are scattered reports from Utah, South Dakota, and perhaps elsewhere north of this general range.

The species ranges over most of Texas with its center of abundance in the central third of the state where it is by far the most numerous species. It has been documented as far west as the Davis Mountains, reported in older records on the BAMONA website from the Panhandle, and overlaps with other species in East and South Texas. In the latter areas, it overlaps broadly with One-banded and Lead-colored Lichen Moths, the last one being probably more numerous in heavily forested parts of East Texas.

Identification. Thin-banded Lichen Moth can be recognized by the combination of an orange vertex, dark thoracic disk, relatively narrow basal orange streak which nearly or actually reaches the PM band, and a narrow, sometimes irregular and sometimes broken orange PM band.

Because of it's variability and similarity to several other species, there has been extensive confusion on how to identify Thin-banded Lichen Moth. Knowlton's (1967) bias against using patterns to identify most Cisthene lichen moths left a major knowledge gap for the past fifty years. This has been compounded by other factors including: (a) overlooking previously described field marks, and (b) biased selection or erroneous identification of images on authoritative sites like MPG and BAMONA. Sources of confusion include the following:

Cisthene tenuifascia AZ8053951-sambiology 100x2
Figure 3. Apparent "Schwartz's Lichen Moth", Cisthene tenuifascia ssp. schwarziorum, Chiricahua Mts., AZ.
Ph. @sambiology, used by permssion.
-- One problem in recent years has been the images available for comparison online. At the present writing (September 2017) it appears that all of the images on the MPG page for Thin-banded Lichen Moth are examples from Arizona and New Mexico and all are of the subspecies schwarziorum ("Schwarz's" Lichen Moth) described by Dyar in 1899, with a very confusing subsequent taxonomic history. Schwartiorum differs from nominate Thin-banded in Texas by having a proportionately wider, complete PM band, yellower colors, and blackish gray ground color. Texas Thin-banded are more variable in these aspects but typically have a narrower PM band; in about a third of specimens, the PM band is broken. Color areas are usually true orange, although yellow examples occur, and the ground color is typically a slate gray on fresh specimens. See the key in the previous journal entry for more illustrations of typical Thin-banded in Texas.

Cisthene unifascia_5184
Figure 4. One-banded Lichen Moth, Burnet Co., TX. Ph. @gcwarbler.

-- One-banded Lichen Moth (C. unifascia). Older literature (pre-1916) did not distinguish what we now call Thin-banded and other species from unifascia, thus old references to the latter included several different lichen moths. To this day, the similarity of the two names (scientific and common) can still cause confusion among non-specialists. In almost all instances, One-banded is easily separated from Thin-banded by the shape of the PM band made up of two broad-based triangles which meet narrowly--or not at all--in middle. The forward edge of the PM band is irregular and deeply indented, the notch appearing nearly rectangular. One-banded Lichen Moth is confined to the s.e. one-half of Texas; it co-occurs widely with Thin-banded in Central Texas and with Lead-colored and Packard's Lichen Moth in East Texas.

Cisthene barnesii TX5852279-Lasley 100x2
Figure 5. Barnes' Lichen Moth, Hays Co., TX. Ph. @greglasley, used by permission.
-- Barnes' Lichen Moth (C. barnesii) is normally recognized by the gray vertex (top of head). It can otherwise be very similar to Thin-banded. Original descriptions of barnesii emphasize the paleness of the gray color on the head and thorax (Dyar 1904, Knowlton 1967), thus presumably lighter than Thin-banded. The "legacy" version of BOLD (version 3) illustrates a single barcoded example of Thin-banded which seems to show gray on the vertex, the only one of 21 images on that page. None of the 25 public data images on BOLD of Thin-banded show a gray vertex, so this condition is assumed to be rare in Thin-banded. If a photo of a purported Thin-banded shows gray on top of the head, the color of the middle legs may be useful: Thin-banded should show at least some yellow-orange on the middle femur, often half or more but at least a smudge at the base of the mid-femur (see Fig. 2, above). The legs of all barnesii are reportedly gray and should show no more than a trace of yellow at the base of the mid-femur, if any (Fig. 5). There is, however, an apparent correlation within all Cisthene of the extent of orange/yellow color in the wings and the amount also on the legs. Range again may help; Barnes' Lichen Moth is generally associated with foothill areas and pinyon-juniper or juniper-oak woodlands; it is unexpected outside of the Trans-Pecos or southern and eastern Edwards Plateau.

Cisthene angelus AZ1084691-Keller 100x2 Cisthene picta OK321853-Dreiling-BG-BOLD 100x2
Figure 6 (left). Angel Lichen Moth, Mt. Lemmon, AZ. Ph. @jaykeller, used by permission.
Figure 7 (right). Pictured Lichen Moth, Washington Co., OK. Mark Dreiling, BOLD public data.

-- There seem to be no confirmed specimens or images of Thin-banded which have a solid orange thorax. Such examples are likely to be either Angel (C. angelus) or Pictured Lichen Moth (C. picta) (Figs. 6 & 7). However, this mark has been overlooked in some online images, placing them erroneously as Thin-banded. The solid orange thorax of those other two species may occasionally show a thin gray line in the rear center of the thorax (Fig. 7). Both Angel and Pictured Lichen Moths typically have a wide basal streak which is usually broadly connected to the PM band. Range is also useful since neither of those two species is expected to occur in deep East or South Texas and angelus is apparently confined mostly to the Trans-Pecos within Texas, ranging east only to the Devil's River.

Cisthene martini AZ321518-Melton-BG 100x2
Figure 8. Martin's Lichen Moth, Cochise Co., AZ. Ph. copyright Charles W. Melton, BugGuide, used by permission.
-- Martin's Lichen Moth (C. martini) is a species primarily of the forested mountains of southern Arizona and adjacent New Mexico and basically looks like a Thin-banded on which the colors are all darkened and oversaturated. At the moment it should be considered hypothetical in Texas. MPG shows a single occurrence of Martin's Lichen Moth in Jeff Davis Co., but the source of that record is unknown to me. Bob Neuelle Jr. collected series of Cisthene moths in August 2015 and July 2016 high in the Davis Mountains which look similar to Thin-banded Lichen Moth but have much darker ground color and much richer red-orange color areas on the FWs (see specimen images on iNat by @rjnjr). Some of these look like good candidates for Martin's Lichen Moth. This identification is speculation on my part and has not yet been confirmed by barcoding or genitalic examination. A Cisthene photo from the Davis Mountains in July 2015 by @aredoubles looks like a standard Thin-banded, similar to populations to the east.

Cisthene subrufa MX4094721-Gonzalezii 100x2 Cisthene subrufa MX2342966-Gonzalezii 100x2
Figures 9 & 10. Tamulipan Lichen Moth, (both) Nuevo Leon, Mexico. Ph. @gonzalezii, used by permission.

-- In South Texas, the poorly known Tamaulipan Lichen Moth (Cisthene subrufa) occurs. The species has been documented several times in northeastern Mexico around Monterrey and at least as far south as eastern San Luis Potosi (iNaturalist observations; Figs. 9 & 10). Color areas on this species are pale creamy yellow rather than orange. A key mark is the basal streak which stops well short of the PM band area. The basal streaks are convex and thus in top view they appear to form a symmetric elliptical pale area flanking the dark thoracic disk, looking like an avocado split in half. Ground color is brownish gray, thus paler than fresh Thin-banded, but faded examples of the latter will appear browner. Size is important: Tamaulipan Lichen Moth is small, with a reported wingspan of 13 to 16 mm (thus FWs about 5.5 to 7 mm) while the smallest individuals of Thin-banded span 16 mm and larger; I have four measured images of Thin-banded with FWs ranging from 8 to 10.5 mm.

Even as I upload the last two images of (assumed) Tamaulipan Lichen Moth for this article, I am challenged to figure out how to separate that species (particularly the example in Fig. 9 on the left) from "Schwarz's Lichen Moth" of southern Arizona (Fig. 3). Over 100 years ago, Dyar (1899) apparently named "Ozodania" (= Cisthene) schwarziorum from two widely separated specimens (AZ and Veracruz); Knowlton (1967) tried to retrace the later use of that name and settle the designation of the type specimens but perhaps even his careful examination was insufficient to properly portray this complexity. I may be in error on my identification of the moth in Figure 9...or Figure 3...or both...or neither. Such is the continuing challenge of learning about this intriguing genus*!

  • UPDATE (10/15/2017): "It's the leg color, Stupid!" Further examination of lots of images suggests that Schwarz's and Tamaulipan Lichen Moths can be distinguished by leg color (see the images above): Schwarz's, being a subspecies of Thin-banded, has mostly gray legs including in particular the middle tibia which are most often easily visible in photographs. By contrast, Tamaulipan Lichen Moth consistently has banded middle legs, especially the tibia which is often yellow in the middle third with gray on either end, and the hind legs are usually all yellow. See my next journal entry: https://www.inaturalist.org/posts/12088-id-guide-3-concluded-more-field-marks

References:

Barcoding of Life Data System (BOLD) website: http://www.boldsystems.org/ Version 4.0 (last accessed 28 September 2017).

Beadle, David, and Seabrooke Leckie. 2012. Peterson Field Guide to Moths of Northeastern North America. Houghton-Mifflin-Harcourt, Boston.

Covell, Charles V., Jr. 1984. A Field Guide to the Moths of Eastern North America. Houghton Mifflin, Boston.

Dyar, Harrison G. 1899. A new Lithosian. Psyche 8(277):359-360. [Describes Ozodania schwartiorum from Arizona and Mexico, but see Knowlton's analysis (1967).]

Dyar, Harrison G. 1904. Descriptions of new forms of the genus Illice Walker. Proc. Ent. Soc. Washington 6(4):197-199. [Describes several new species and varieties. All descriptions are very brief, based on one to seven specimens. Includes key to all known species and varieties.]

Holland, W. J. 1903 (1968 Dover reprint). The Moth Book. Dover Publ., New York. [Key to seven spp. of "Illice" (= Cisthene) on p. 109.]

Knowlton, Carroll B. 1967. A revision of the species of Cisthene known to occur north of the Mexican Border (Lepidoptera: Arctiidae: Lithosiinae). Trans. Amer. Ent. Soc., 93(1):41-100. Link to pdf copy available on BugGuide: http://bugguide.net/node/view/790908

Lotts, K. and T. Naberhaus, [coordinators]. 2017. Butterflies and Moths of North America (BAMONA). Bozeman, MT: Big Sky Institute. On-line posting: (http://www.butterfliesandmoths.org/, Version 09282017), accessed 28 September 2017.

Moth Photographers Group (MPG) website: http://mothphotogrphersgroup.msstate.edu (last accessed 28 September 2017).

Muller, Joseph. 1976. Third addition to the supplemental list of Macrolepidoptera of New Jersey. J. New York Ent. Soc., 84(3):197-200.

Neumoegen, B. and H. G. Dyar. 1893. A preliminary revision of the Bombyces of America, North of Mexico. J. New York Ent. Soc. 1(3):97-118. [p. 115 has brief key to 7 spp.]

Powell, Jerry A., and Paul A. Opler. 2009. Moths of Western North America. Univ. of Calif. Press, Berkeley.

Posted by gcwarbler gcwarbler, September 27, 2017 21:59

Comments

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Chuck, this is absolutely great. It's well researched, clearly written, and badly needed. Thanks so much for this contribution.

Posted by ptexis over 3 years ago (Flag)
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Wonderfully written - I have many dozen specimens from Arizona and West Texas and I will have to go back and carefully review each one!

Posted by rjnjr over 3 years ago (Flag)
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@rjnjr Bob, be aware that there is at least one other species in Arizona (Cisthene coronado) that is very similar to Martin's Lichen Moth and I haven't studied that one. Knowlton couldn't separate the females (by any means).

Posted by gcwarbler over 3 years ago (Flag)
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@pfau_tarleton -- be on the lookout for this genus.

Chuck, again, magnificent research here! I'll be especially happy when I see more of these moths. :)

Posted by sambiology over 3 years ago (Flag)

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