Journal archives for December 2022

December 7, 2022

Eudesmia cypris: A distinctive lichen moth from central Mexico

Resumen (español): Entre las varias especies del género de líquenes Eudesmia descritas en México, E. cypris se reconoce fácilmente por su tórax negro. Por lo demás, es muy similar a E. arida. Ocurre en las tierras altas del centro de México en los estados de Aguascalientes, Guanajuato, Jalisco, Michoacán y el sur de Zacatecas.


Eudesmia cypris (L to R): Agauscalientes, @leptonia | Michoacán, @minerva31 | Michoacán, @elrayman210

In my continuing review of the literature on the lichen moth genus Eudesmia, I have tried to carefully read the original descriptions, compare those to the earliest published drawings of the species (often from the type specimens), and then compare these to the array of modern images available on iNaturalist and other repositories. This is very challenging for the populations of this genus in Mexico. There are no less than 11 species names that have been applied to various Eudesmia populations in Mexico. Many of these are likely to be synonyms because of the variation in color and patterns that wasn’t appreciated by researchers in the 19th Century (see my journal entry on this topic). However, a few of the named species have distinctive enough characters to be recognizable in modern images.

One such species is Eudesmia cypris (Druce, 1894) (originally described in the genus Ruscino; see below). Druce described the species from a specimen from Lake Chapala, Jalisco, Mexico. This is a blackish moth with the standard Eudesmia orange-yellow median band across the forewings, a subterminal arc of the same color, and with the basal part of the hindwings also orange-yellow. Druce described the median orange-yellow band as “wide”, but his illustration in volume 3 of the moth volumes of Godman & Salvin’s Biologia Centrali-Americana (plate 78, figure 5; see below) shows a Eudesmia with a rather narrow median band compared to the variation seen in various other populations and species. The margins of this median band are fairly straight.

Druce BCA III 78-5 Ruscino cypris annotated

The subterminal orange arc is much like that in Eudesmia arida in that it does not quite reach the costal margin of the forewing. Most importantly, however, Druce further described the species as having the “head, antennae, thorax, abdomen, and legs black; collar and tegulae orange-yellow.” The black thorax and abdomen are evident in the aforementioned image in the Biologia and these are distinct from all other populations of Eudesmia in Mexico. The next nearest species with black on the thorax are the distinctive Eudesmia unicincta and Eudesmia lunaris of Colombia and Venezuela. Populations of other named Eudesmia species all around E. cypris have an entirely orange-yellow head, thorax, and abdomen.

As I reviewed observations on iNaturalist, I encountered a distinct set of images in the highlands of central Mexico with the diagnostic black center of the thorax, surrounded by the orange collar and tegulae as described by Druce. They occur in a geographically unified region in the interior of Mexico in the states of Aguascaliente, Guanajuato, Jalisco, Michoacán, and Zacatecas (see screen capture from iNat, below). I conclude that these all represent Eudesmia cypris. The species appears to be confined mainly to the western portion of the Trans-Mexican Volcanic Belt (TMVB)(see map below) and nearby highlands of the Sierra Madre Occidental to near Zacatecas (city). There are no images yet of the species on the Pacific coastal slope of west Mexico and none south of the TMVB.

Map Eudesmia cypris iNat 20221206
Map of Eudesmia cypris observations, as of 7 December 2022. For another version of a range map of Eudesmia cypris, see my journal entry on testing SimpleMappr.

Perez-Moreno et al 2021 Fig 1 TMVB crop 2nd
Trans-Mexican Volcanic Belt (TMVB). Adapted from Pérez-Moreno et al. 2021. Appl. Sci. 2021, 11(13), 6126. Open Access, downloaded from mdpi.com.

Thus far this range seems to be allopatric with (i.e., completely separate from that of) Eudesmia arida which occurs south to northern Zacatecas in the west and across the arid Mexican plateau to Nuevo Leon, San Luis Potosi, and Hidalgo. I haven’t found any other obvious field marks for separating cypris and arida in images of living moths except for the black thorax (which is all orange in arida). It is conceivable that cypris is just a regional color morph of arida (in which case, “Eudesmia cypris (Druce, 1894)" would have name priority over “Eudesmia arida (Skinner, 1906)”), but that must await proper phylogenetic studies with genitalic examination and DNA analysis.

References

Druce, H. 1894. Descriptions of some new species of Heterocera from Central America. Ann. Mag. Nat. Hist. (6)13:168-182.

Druce, H., 1881-1900. Biologia Centrali-Americana. Insecta. Lepidoptera-Heterocera, Vol. I., Vol. II (1891-1900), Vol. III (Plates; 1891-1900). Edited by F. D. Godman and O. Salvin. Links to BHL: Description of Ruscino cypris in Vol. II; link to plate 78 in Vol. III.

Skinner, H. 1906. New butterflies and moths with notes on some species. Entomol. News 17(3):95-96.

Posted on December 7, 2022 06:00 PM by gcwarbler gcwarbler | 2 comments | Leave a comment

December 19, 2022

Testing SimpleMappr

I'm learning how to use SimpleMappr (SimpleMappr.net) to create distribution maps. Here I'm going to try to embed the first map I created. It shows the distribution of five species of Eudesmia lichen moths in southern South America. The data are mostly from a download of all iNat sightings of four of the species as of Dec. 8, 2022, with the addition of a couple of records from earlier literature. Please don't take this as a final product of anything. I'm still working on the data set. This is just an EXAMPLE of the use of SimpleMappr.

The next test is to show a downloaded version of a map which I then uploaded to Flickr and will embed here. This shows the distribution of observations of Eudesmia cypris in Mexico, from iNaturalist data as of Dec. 8, 2022. This can be compared to the (adjacent) screen capture of the iNat observation map from my previous post on this species. (There are more dots on the iNat screen capture because it includes a few sightings on which there isn't community agreement yet, e.g. the original observer or subsequent identifier has not yet concurred.)

Eudesmia_cypris_1350 Map Eudesmia cypris iNat 20221206

Well, that seems to work OK. Don't worry about the size of the legends, scales, etc. These versions of the images have been reduced just to fit conveniently in the journal format.

Posted on December 19, 2022 03:25 AM by gcwarbler gcwarbler | 8 comments | Leave a comment

December 22, 2022

Recognizing Eudesmia quadrifasciata of southern Mexico

Resumen (español): Eudesmia quadrifasciata es muy similar a E. arida. Su principal carácter distintivo, la mayor parte de las alas traseras negras, no es evidente en las fotos de campo. Las diferencias sutiles en la forma de la mancha subterminal en las alas anteriores pueden ayudar a distinguir la especie; esta mancha es más corta y más en forma de lágrima en quadrifasciata que en arida. Los rangos de las dos especies están muy separados. E. quadrifasciata se encuentra desde el estado de México al sur hasta Oaxaca.


Eudesmia quadrifasciata: Acatlán, Puebla @hildeberto | Zapotitlán, Puebla @bsullend

Eudesmia quadrifasciata: Ixtapan de la Sal, México @mizrain | Zapotitlán, Puebla @monitorzapotitlansalinas

The lichen moth Eudesmia quadrifasciata (Erebidae: Arctiinae) is very similar to E. arida of northern Mexico and the southwestern United States. Walker (1865) described "Gerba quadrifasciata" from Oaxaca, Mexico, from a single male specimen. It's primary distinguishing character is the mostly black hindwing with just a small basal spot of orange, a character that will be unrecognizable in most field photos. Other than this aspect, Walker's brief original description does not allow for handy discrimination from most other Eudesmia which occur in Mexico. Of note, however, Walker did mention that the subterminal crescent "narrows towards the interior angle, which it does not reach." Hampson's (1900) redescription of quadrifasciata and illustration of the type (below) indicate that the subterminal crescent runs from "just below the costa to just below vein 2", i.e., somewhat shorter than the more northern E. arida and unlike E. menea. The illustration of E. quadrifasciata by Hampson (1900, pl. 25, fig. 23, below, left) shows a forewing that is probably indistinguishable from that of E. arida but Draudt's illustration (1918, pl. 35, row i, below, right) emphasizes that the subterminal crescent is short and teardrop-shaped (thicker anteriorly, narrowed posteriorly). As with populations of other species/phenotypes, the hue of the color bands and their widths vary quite a bit within the small available set of images. None of the available images on iNaturalist shows a view of the hindwing or abdomen.

Eudesmia quadrifasciata Hampson 1900 Eudesmia quadrifasciata Draudt 1918

Among iNaturalist observations as of 20 December 2022, I identified 9 observations in the Mexican states of Oaxaca, Puebla, Morelos, and Mexico which have a distinct short, teardrop-shaped subterminal crescent (map, below). An additional somewhat disjunct record in the state of Jalisco appears to be of the same phenotype:
Eudesmia_quadrifasciata_1350_rect

Dyar's (1917) "Cisthene" [= Eudesmia] tehuacana, described from Tehuacán in the state of Puebla, Mexico, apparently differs from E. quadrifasciata only in that the abdomen is "black above, except at base and tip". I expect this is just a regional variant of E. quadrifasciata.

References:

Draudt, M. 1918. 61. Genus: Cisthene Wkr. Pp. 273, In: A. Seitz, The Macrolepidoptera of the world: a systematic account of all the known Macrolepidoptera. Division II: The Macrolepidoptera of the American Region, Vol. 6. The American Bombyces and Sphinges. Publ. 30, XI, 1918.

Dyar, H. G. 1917. A note on Cisthene. Ins. Insc. Menstr. 5:8-10.

Hampson, G. F. 1900. Catalogue of the Lepidoptera Phalaenae in the British Museum. Vol. 2. Catalogue of the Arctiadae (Nolinae, Lithosianae) in the Collecion of the British Museum. London. 589 p.

Walker, F. 1864 [1865]. List of the Specimens of Lepidopterous Insects in the Collection of the British Museum. Part XXXI--Supplement. Printed by order of the Trustees, London.

Posted on December 22, 2022 03:41 AM by gcwarbler gcwarbler | 1 comment | Leave a comment