Escalantiana J.Y. Miller, 2019

González, Jorge M., López, Bernardo, Huerta, John Phill & Miller, Jacqueline Y., 2019, A new genus of Castniinae (Lepidoptera Castniidae) with comments on comparative morphology and bionomics of its assigned species, Zootaxa 4668 (1), pp. 89-104 : 93-101

Description of Escalantiana J.Y. Miller , gen. nov.

( figs. 1–13 )

Type species. Castnia escalantei (J. Y. Miller, 1976: 7) , by present designation.

Taxa included in Escalantiana J.Y. Miller gen. nov.

escalantei (J.Y. Miller 1976) (Castnia) n. comb.

chelone (Hopffer, 1857) (Castnia) n. comb.

estherae (J.Y. Miller 1976) (Castnia) n. comb.

Male Diagnosis. Forewing. Ground color grayish-brown with pale bifurcate Y-shaped marking which extends from the subcosta across the end of the discal cell and terminates in Cu 2 -1A; diffuse postdiscal spot band extends from near apex to anal angle and reveals the darker spot band below; two irregular gray-brown spot bands along the submargin; base of wing gray-brown mixed with darker brown and black; numerous battledore-shaped scales present overscaling darker areas. Ground color ventral forewing paler warm ashen-brown basad overscaled with bluishblack in cell basad and terminating along a dark blackish-brown angular transverse band across the mid-discal cell, which is overscaled heavily with tawny along the distal edge; the Y-shaped markings from above are evident by two other bluish-black markings but reduced and edged heavily in tawny. These include: (1) a globular marking at end of the discal cell, which extends from R 1 -R 2 to M 2 -M 3; and (2) a postdiscal spot band which extends from R 3 -R 4 to Cu 1a -Cu 1b with fainter markings in Cu 1b -Cu 2 and Cu 2 -1A. Intervening areas of Y-shaped markings and area along submargin warm ashen-brown. Veins darkened, warm ashen brown on both wings. Fringes above and below warm ashen brown to fuscous shading to tawny at anal angle and along anal margin.

Hindwing. Dorsal ground color fuscous gray-brown with prominent black markings with a few interspersed iridescent blue scales. Margin bordered heavily in tawny posteriad which extends from near base of wing at 1A- 2A across the mid-cell toward the costal margin and recurves back as an extradiscal spot band edged on the inner and outer margins with tawny; an undulate diffuse gray-brown submarginal band and edge of lateral margin warm brown; basal erect androconial patch in cell. Ventral ground color warm fuscous ashen brown with markings similar to above but black markings not contiguous, without iridescent blue scales, and edged heavily in tawny with a few tawny scales overscaled on black areas; dense erect scales or pilli present in the secondary accessory cell. Fringe dorsally warm ashen gray-brown to fuscous shading to ashen gray-brown with tawny along anal margin.

Females are similar to males in terms of coloration and markings with double raised scales including even iridescent bluish scales on the dorsal hindwing ( fig. 1 ). The angular black marking on the hindwing cell below is more produced distad in the females. There can be a single, circular dark black-brown spot in the hindwing cell in either sex.

Antennae dorsally and ventrally tawny and equal to one-half length of forewing costa, comprised of 63–68 segments; male nudum/apiculus, 9/18; female 9/23–9/25. Head, ashen gray-brown. Labial palpi fuscus, brown or cream extending along the eye length with the distal segment approximately one-fifth length of the second segment; proboscis absent or reduced. Legs ( fig. 11 ): foreleg epiphysis reduced; both pairs of tibial spurs reduced but present on the mesothoracic and metathoracic legs; numerous spines on tarsi and also present on the outer margin of the tibia.

Abdomen dorsally fuscous gray-brown with darker brownish-black at posterior margin of abdominal segments; ventrally tawny shading to fuscous or gray-brown posteriad.

Wing venation ( fig. 12 ; Miller 1976) with the discal cell closed and with the tracheated recurrent vein and radial accessory vein somewhat reduced; subcosta free with R 3 arising from R 2 two-thirds along forewing costal length; R 4 and R 5 somewhat connate at base; 2A incomplete with crossvein 1a-2a stalked and curved toward anal angle. Hindwing with discal cell closed in part; origins of Rs, M 1, and M 3 approximate; prominent erect setose scales extend across secondary accessory scales and posteriad to anal margin. Frenulum bristles in female less than six.

Male genitalia ( figs. 6 , 9 ). The genitalic capsule is miniaturized with the uncus foreshortened and fused into a single square-shaped protuberance; dorsal uncus with a few raised small jagged bumps centrally and membranous area and along uncus with several blunt trichoid sensillae; gnathos heavily sclerotized and fused anteriad, deeply excavate posteriad, slightly dentate; subscaphium darkly sclerotized with deep indentation; valvae markedly reduced in size with distal portion recurved; saccus divided, and with dorsal portion heavily sclerotized. Phallobase recurved, heavily sclerotized, similar in diameter throughout and approximately equal to the length of the end of the saccus to the end of the valvae; aedeagus somewhat flattened, asymmetrical with heavily sclerotized plate contiguous with the main portion of phallus in sinistral view; membranous in dextral view.

Female genitalia ( fig. 13 ). Papillae anales blunt, moderately sclerotized, heavily setose; anterior and posterior apophyses not equal in length; sterigma lightly sclerotized in both dorsal and ventral views with lightly sclerotized plate posteriad of ostium bursae; setal tufts evident laterally and on sterigma dorsally and ventrally; ductus bursae lightly sclerotized near junction with bulla seminalis, membranous and undulate distad; corpus bursae and bulla seminalis membranous.

Early Stages and Foodplant Association. The type species is associated with Blue Agave ( Agave tequilana F.A.C. Weber ; Asparagaceae ) ( González Hernández et al. 2007). Escalantiana chelone n. comb. has been found boring in other Asparagaceae ( Agave striata Zucc. ) ( Aldasoro Maya 2000a, 2000b, 2003; Ramos-Elorduy et al. 2011), while E. estherae n. comb. possibly attacks certain Bromeliaceae (see discussion below).

Flight Period: All specimens of the original type series were collected from May through August.

Etymology. The genus is named to honor Dr. Tarsicio Escalante senior, who made so many excellent contributions to our knowledge of Mexican Lepidoptera and for his immeasurable generosity in sharing his knowledge with other members of the scientific community throughout the world. The gender of the name is feminine. It should be noted that Escalantiana estherae n. comb. was named in honor of his wife, Esther ( Miller 1976).

Geographic distribution. The original type series of E. escalantei included 11 specimens from the Mexican states of Chihuahua and Morelos, but most of them from various localities in Guererro. The type of E. estherae n. comb. was reported from Jungapeo, Michoacán, but specimens have been collected in Zoyatepec and Acahuizotla, Guerrero. One of the specimens of the type series, as well as specimens of E. chelone n. comb. are known from a few localities in Hidalgo. Consequently, the genus seems to be restricted to Mexico.

Comments. Castnia chelone ( figs. 2 , 7 ) was originally described by Hopffer (1856) based on two males and one female from Mexico (“Drei Exemplare, Zwei Männchen, ein Weibchen von Mexico ”). Miller (1976) designated one of the males as the lectotype. Curiously the lectotype was subsequently stolen from the MfN, together with many other specimens, by an unscrupulous dealer (R. Worthy, pers. comm.). Fortunately, a collection given to the Museum by the heirs of an Ernst Jugl contained “many of the stolen specimens which it is believed he bought from the dealer in question. Amongst these was the lectotype of chelone along with several other castniid types.” (R. Worthy, pers. comm.). Later, Houlbert (1918) placed E. chelone in the genus Sympalamides [sic] based not on actual specimens but on the figures in Hopffer (1856), Preiss (1899) and Strand (1913). From Houlbert’s (1918) notes on E. chelone , it appears that he was uncertain of the relationship between this species and the other species in the genus ( Miller 1976). Castnia escalantei (= E. escalantei ) was later described by Miller (1976) based on seven males and four females collected from several localities in three Mexican states. Miller (1976) also described Castnia estherae (= E. estherae ) based on a single female specimen collected in Purúa, Michoacán, Mexico. Eventually, Miller (1995) and Lamas (1995) placed Castnia chelone and C. escalantei in the genus Synpalamides , which comprises mostly Brazilian species, these two being the only ones in the group from outside South America. The latter designation was kept by Moraes & Duarte (2014). Curiously, E. estherae was not mentioned by Miller (1995), and Lamas (1995) and Moraes & Duarte (2014) preserved it in the genus Castnia Fabricius.

The present distribution of neotropical Castniinae seems to support vicariance events described by Rosen (1978) (“a major vicariance event during the early tertiary led to the eastward drift of the proto-Antilles relative to their position between nuclear Central America and South America. This resulted in the fragmentation of the more-or-less continuous biota into Middle America, Antillean, and South American components. With the extensive mountain building in northern Mexico, this same process isolated both the northern and southern elements of the Middle America biota …” Miller 1986). Synpalamides is a genus found mostly in Southeastern Brazil, even though some species have been recorded as far west as Bolivia and as far North as Venezuela and Trinidad (Ríos & González 2011, Penco 2011, González & Worthy, 2017). According to Rosen’s (1978) theory, the range of the ancestral stock of Synpalamides was possibly more widely distributed in the early tertiary ( Miller 1986). But after the eastward drift of the proto-Antilles into their current position, that ancestral stock generated today’s endemic Ircila Houlbert (only found in Hispaniola), Synpalamides proper in South America (mainly Eastern Brazil, but other South American countries) and a Mexican group (“ancestral Synpalamides ”). Thus, the “ancestral Synpalamides ” would become the herein proposed genus Escalantiana gen. nov. whose associated species E. chelone n. comb., E. escalantei n. comb., and E. estherae n. comb., share certain morphological features, such as wing venation, scale development, and male and female genitalia, that align them close to Corybantes . However, their distributional range [ Corybantes species are mainly South American, even though C. veraguana (Westwood, 1877) has been reported from Panama] has been restricted for such a long time that sufficient evolutionary isolation has certainly occurred ( Miller 1986).

A phylogenetic analysis was done by Miller (1986) with a selection of apomorphic characters based on the method of argumentation scheme ( Hennig 1966). The chosen outgroups to compare with the Neotropical Castniinae were the Cossinae (Cossidae) and the genus Synemon Doubleday ( Castniidae : Castniinae : Synemonini) which were regarded as ancestral groups ( Miller 1986). Miller (1986) used a large number of morphological characters to perform several analyses resulting in three phylogenetic trees. Miller’s (1986) results show that in every cladogram, the genus Escalantiana gen. nov. appears close to Eupalamides , Amauta , and Corybantes , while appearing distantly related to Synpalamides Hübner , though the latter is clearly basal to Escalantiana gen. nov. Even though Moraes & Duarte (2014) present a comprehensive phylogenetic analysis of the family, they did not study these Mexican species and kept them under the assignments provided by Lamas (1995).

As discussed above, Houlbert (1918) and others originally placed Castnia chelone in the genus Synpalamides due to the similarity of the forewing markings. However, members of Synpalamides have a coiled proboscis while species of Escalantiana gen. nov. have either a reduced or aberrant proboscis. The palpi are reduced in E. chelone n. comb. and E. escalantei n. comb. but somewhat larger in E. estherae n. comb. In addition, there are a number of distinctive features that distinguish Escalantiana gen. nov. from Synpalamides . Those include the Y-shaped forewing markings with the two layers of wing scales along with specialized wing scales and androconial scale patches basally on the forewing. Also, the hindwing, dorsally, and especially the ventral hindwing in Escalantiana gen. n. Black markings with iridescent blue scales are present on the hindwing in both sexes (in E. escalantei n. comb.). Androconial scales in cell basad and the setal brush in the cell extending along M 1 (in E. estherae n. comb.) as well as other specialized scales. While it is not unusual to see the setal patches on the dorsal hindwings in a number of the Castniini , the number of specialized androconial and other types of scales present on the wings in Escalantiana gen. nov. is remarkable. Finally, the reduced male genitalic capsule is present in all three species ( figs. 6–8 ) and specialized trichoid sensillae are evident near the uncus of the males ( fig. 9 ). Contrary to Synpalamides whose phallobase is thin, deeply curved, somewhat contorted, and less than half the length of the aedeagus, with the latter terminating with a straight lateroterminal projection at the tip ( Miller 1986; Moraes & Duarte 2014; González & Worthy 2017).

Bionomics. Even though E. estherae n. comb. was originally known from a female holotype from Purúa, Michoacán, the additional specimens reported herein were all found in Zoyatepec, Guerrero, considerably extending the geographic range of the species. There is a possibility that the species might also be found in the southwestern forests of the state of Mexico. The region where our specimens were found is clearly a low elevation Tropical Deciduous Forest. The collection site is in a transitional zone with grasses ( Poaceae ), numerous bushes and oaks ( Fagaceae ) and pines ( Pinaceae ), with an abundance of epiphytic bromeliads ( Bromeliaceae ) and orchids ( Orchidaceae ) on most larger trees ( fig 14a, b ). Thus far, we have identified its potential larval hostplant as Tillandsia prodigiosa (Lem.) Baker (Bromeliaceae) ( fig.14c ). This plant is the most abundant bromeliad in and around the collecting site.

However, a paper on edible Lepidoptera in Mexico ( Ramos-Elorduy et al. 2011) provided information on a different host ( Agave striata Zucc. , Asparagaceae ) for another species in the genus, Escalantiana chelone n. comb., which has been infrequently encountered in museum and private collections. Miller (1986) proposed that perhaps these insects were using Agave spp. as larval hostplant. In fact, native tribes of Hñähñu, Nahuatl and Otomi ethnicity in Hidalgo, Mexico, use the larvae of E. chelone n. comb. rather extensively in their diet, they are consumed fried, most especially during Easter and are collected from Agave striata , a rather unusual plant native to northeastern Mexico ( Aldasoro Maya 2000a, 2000b, 2003; Ramos-Elorduy et al. 2011). Their habitat is tropical deciduous forest and extends to 2000–2600m elevation with tropical species present in gallery forest in addition to a scrub oak-juniper association and permanent streams in the valleys during the winter. Thus, the representatives of this genus have adapted to some rather interesting and distinct habitats. Also, González Hernández et al. (2007) report “ Castnia chelone ” (but the pictures presented show that it is clearly E. escalantei n. comb.) attacking blue agave ( Agave tequilana F.A.C. Weber ) in Tequila, Jalisco ( fig. 1 ). It appears that E. escalantei n. comb. (sometimes confused as Castnia chelone , but other times as Aegiale hesperiaris (Walker) or Acentrocneme hesperiaris Felder & Felder , Hesperiidae ) was frequently found attacking the crop during the 1950s but more recently it is uncommon (H. González H., pers. comm.; González Hernández et al. 2007; CMFCP 2007). It seems that E. escalantei n. comb. bore holes around the base of the leaves but do not penetrate deep inside the stem of the plant and its damage has not been associated with secondary phytopathogens as happens with other borers of agave plants (H. González H., pers. comm.).

Most specimens of E. estherae n. comb. mentioned herein were collected while flying between 11:30 and 13:30 hours on partially clouded sunny days, with temperatures oscillating from 29 to 30°C and relative humidity around 45%. If it is too cloudy, they do not fly. Males start flying at around 11:00 to 11:30 while the few females collected in Zoyatepec were flying after 12:00 and until around 13:30. They have a fast, horizontal flight covering distances of 4–5 m and back, but occasionally longer distances (10–20 m). While flying, these moths might suddenly ascend along the slopes. Most of the individuals collected were flying around the T. prodigiosa plants, but they were not observed perched on any of them. To rest, they perched on dry branches of the understory bushes. They perch in a typical castniid manner with their abdomens hanging down while their head is pointing up, assuming the typical stegopterous position of the wings, with their antennae pointing forward.

A male and a female of E. estherae n. comb. in the possession of Robert Westphal, Spain, were collected in Acahuizotla, Guerrero, 1200m in May 2018 (R. Westphal, pers. comm.). This is a locality relatively close to Zoyatepec, at about the same altitude and with the same kind of vegetation. All Zoyatepec, Guerrero, specimens of E. estherae n. comb. mentioned above were collected from March to April, which is the time of the year preceding the heavy rains. These months are not commonly chosen to collect Lepidoptera because it is too dry. Also, most known Mexican Castniidae normally fly during and after the first rains which occur sometime around May–June. Unfortunately, the forests around Zoyatepec are poorly collected since they are considered to be unsafe as illegal opium poppy ( Papaver somniferum L., Papaveraceae ) plantations are not uncommon in the surrounding areas.

Figures

FIGURE 9. Escalantiana escalantei (J.Y. Miller) n. comb., posterior view of uncus and tegumen.

FIGURE 11. Escalantiana escalantei (J.Y. Miller) n. comb. legs: (a) foreleg; (b) midleg; (c) hindleg.

FIGURE 12. Escalantiana escalantei (J.Y. Miller) n. comb. male palpus and male wing venation.

FIGURE 13. Escalantiana escalantei (J.Y. Miller) n. comb., female genitalia (dorsal Slide M-3028, Jacqueline Y. Miller) Mexico: Guerrero: Acahuizotla; v. 1958; Tarcisio Escalante.

FIGURE 14. Habitat in which Escalantiana estherae (J.Y. Miller) n. comb. was collected in Zoyatepec, Guerrero, Mexico: a) access to site showing bushes and some of the tree species; b) Tropical Deciduous Forest with oaks with multiple epiphytic plants; c) Tillandsia prodigiosa (Lemaire) Baker (Bromeliaceae) plants on branches of an oak (Quercus sp., Fagaceae). (Photos: John Phill Huerta P.).

FIGURES 1–4. Specimens of three Castniidae collected in Mexico: 1) Escalantiana escalantei (J.Y. Miller) n. comb., male, Tequila, Jalisco, ex-larva in Agave tequilana Weber var.Azul (photo: Jorge Valdez Carrasco); 2) E. chelone (Hopffer) n. comb., male, Ixmiquilpan, Hidalgo (photo: Adolfo Ibarra); 3) E. estherae (J.Y. Miller) n. comb., female, Zoyatepec, Guerrero (photo: Bernardo López G.); 4) E. estherae (J.Y. Miller), male, Zoyatepec, Guerrero (photo: Bernardo López G.).

FIGURE 5. Escalantiana estherae (J.Y. Miller) n. comb. male wings showing androconial patches with long, hair-like scales, in the hindwing, dorsally (a) and in the forewing, ventrally (b). The arrow points to a crest of long scales that originate in the inner margin of the forewing (ventrally) and bend over the dorsal side of the hindwing. Only when both wings are highly spread (as in the photograph), can these scales be seen.

FIGURES 6–8. Male genitalia (lateral view) of three species of Castniidae: 6) Escalantiana escalantei (J.Y. Miller) n. comb., (genitalia preparation M-2543, Jacqueline Y. Miller), Paratype, Acahuizotla, Guerrero, Mexico; viii.1973. Coll. A. Diaz Francis.; 7) E. chelone (Hopffer) n. comb. (from Miller (1976) Bull. Allyn Mus. 34: 1–13); 8) E. estherae (J.Y. Miller) n. comb. (genitalia preparation, Fernando Hernández-Baz), Zoyatepec, Guerrero, Mexico, iv.6.2016, Coll. J. P. Huerta P. (a) genital capsule; (b) phallus (phallobase + aedeagus); (c) uncus, dorsal view.

FIGURE 10. Escalantiana escalantei (J.Y. Miller) n. comb. female adult dorsal (above) and ventral (below) views.