Castnia amalthaea H. Druce, 1890

Worthy, Robert, González, Jorge M. & Ríos, Sergio D., 2019, A review of the genus Insigniocastnia J. Y. Miller, 2007 (Lepidoptera: Castniidae) with notes on Castnia amalthaea H. Druce, 1890, Zootaxa 4550 (2), pp. 277-288 : 278-281

Castnia amalthaea H. Druce, 1890

Having decided that Athis amalthaea should be restored to the genus Castnia based on general morphology, wing venation and the many similarities to Castnia invaria Walker, 1854 , we searched for more information about it. Druce (1890) does not give the number of specimens or the sex but the description appears to be from a single specimen. The only specimen that has been found is the one in NHMUK which is a female ex-Druce and matches the original description ( Figs. 1, 2 ); this is therefore the holotype fixed by likely monotypy. Druce only gives a brief description but writes “This species is allied to Castnia Therapon, Kollar. ” Castnia therapon Kollar, 1839 is another species that was originally described in the genus Castnia but then treated as being in Athis ( J. Y. Miller 1986, 1995; Lamas 1995b); it was subsequently transferred to Imara Houlbert, 1918 by Moraes (2009) to be later corroborated by Moraes & Duarte (2014). We have found no evidence to suggest that amalthaea is closely related to therapon . Druce (1890) gives as the type locality only “ Brazil ”, there is no further information on the specimen labels so the type locality cannot be further restricted.

The search for further specimens proved fruitless until RW spotted a specimen that looked similar to C. amalthaea in Thierry Porion’s collection. The specimen, from Argentina, had been identified as Castnia lecerfi Dalla Torre, 1913 and the clear resemblance showed us that C. amalthaea and C. lecerfi could be one and the same species.

Unfortunately, C. lecerfi is also a very poorly known taxon. It was originally described as Castnia wagneri Le Cerf, 1911 ; Dalla Torre (1913) then realised that this name was preoccupied, being a junior homonym of Corybanthes (sic) wagneri Buchecker, [1880] , now considered to be Telchin evalthe wagneri from Colombia. He gave it the replacement name Castnia Le Cerfi (sic). Le Cerf (1911) described C. wagneri based on one male from Misiones, Argentina (data below) which is now in MNHN ( Figs. 3, 4 ). Having studied the specimen, the great similarity to the C. amalthea type specimen confirmed our suspicions about their synonymy. The fact that C. lecerfi was treated as a species of Castnia by Lamas (1995b) and accepted as such by Moraes & Duarte (2014) also confirmed our opinion that its senior synonym, C. amalthaea , belongs in the genus Castnia .

Breyer (1931) mentioned that the habitat of the species is “ Santiago del Estero, Argentina ” (this does not coincide with the locality of the holotype so it is not clear why he states it) and that he possessed a female, now in MLPA, from the same locality, whose figure appears in his 1931 paper. He also lists and figures a male from “Mogotes, La Rioja” which he lists as allotype ( Breyer 1931) ( Fig. 5 ). This male, now also in MLPA as are all the ex-Breyer specimens, has a label “ Argentina, La Rioja, Patquia” and a red label reading “Alotipus”; the localities Mogotes [Colorados] and Patquia are only about 25km apart. Breyer thought that Le Cerf described wagneri from a female, so he “designated” a male in his collection as “allotipo”, a spurious designation which carries no type status. In the collection of Mateo Zelich there is another specimen from La Rioja Province, he originally had two from the same locality but the other is now in the collection of Thierry Porion. ( Fig. 6 )

Subsequently, RW found the holotype and paratype of C. minerva R. Krüger, 1926 in NHMUK ( Figs. 7, 8 ), previously synonymised with Castnia invaria penelope Schaufuss, 1870 by Lamas (1995b). These specimens are from Paraguay and are a good match for the holotype of C. lecerfi so clearly belong to C. amalthaea . No other specimens have been found under this name.

There are two very different phenotypes in this species, the more common one seems to be the one with fairly large white patches on the hindwing as represented by the holotype of C. lecerfi ; all the specimens from Santiago del Estero have larger white patches and both specimens of minerva have more white still, and are also of this phenotype. The holotype of C. amalthaea represents the other form which has no white on the hindwing and appears much redder; it also has much narrower forewing white bands. The specimen in coll. Zelich is also of this form. The Breyer specimen from La Rioja and the specimen in coll. Porion are intermediate, which is what led us to realise that C. amalthaea and C. lecerfi are the same species. The amalthaea holotype has only “ Brazil?” as the locality data; the “?” suggests that Druce had doubts about the provenance so it cannot necessarily be trusted and can be disregarded. All other specimens known of the amalthaea phenotype or intermediates were taken in La Rioja Province, which is the most south-westerly known area of distribution and furthest from the Brazilian border. In MLPA there is another female specimen collected by Breyer sometime later in Formosa Province ( Fig. 9 ), this specimen may be a male but as we have been unable to examine it we follow Penco (2011). This is identified as C. lecerfi but has a very different phenotype, being intermediate between C. amalthaea and C. endelechia H. Druce, 1893 . The forewings are the same as in C. amalthaea but the hindwings are more reminiscent of C. endelechia , which is known to occur in Formosa; in size, it also seems to be intermediate between the two.

Before 2018 these were the only specimens known and all of the Argentine ones except for the Porion one were illustrated in Penco (2011).

In February 2018, Alejandro Borquez (pers. comm.) and Carlos Calderón collected nine males of C. amalthaea in Santiago del Estero, Argentina, doubling the number of known specimens. Borquez had been to the locality several times before but had never seen C. amalthaea there, the only Castniid he’d found there was Geyeria uruguayana (Burmeister, 1880) ( Moraes & Duarte (2014) proposed the new combination Paysandisia uruguayana ). Apparently, it had been a very wet season in this area which could have triggered emergence after the moths had spent several years in the pupal form. All the specimens taken are of the form with white on the hindwings like the C. lecerfi holotype ( Figs. 10–12 ), but several others were seen, one female of which was of the red ( amalthaea ) form. Although all the specimens caught were males, females were also seen and had a very different flight. The Argentinean habitat appears to be fairly open, arid scrubby areas in the Gran Chaco ( Figs. 13 , 14 ) and males fly constantly about 1–1.5 metres above the ground along animal tracks between about midday and 2:00 p.m. Females are clearly larger and fly higher, above the thorny bushes, about 2–3 metres above ground level or even higher; they also tend to fly later in the afternoon. Apparently, the larvae feed on a small to medium sized bromeliad ( Bromeliaceae ) which grows very locally in the mountains on trees such as Schinopsis balansae (Quebracho colorado), Aspidosperma quebracho-blanco (White quebracho), Prosopis nigra (Red carob), Prosopis alba (White carob) and Schinus molle (Peruvian peppertree). In March 2018 Borquez also collected two males in Misiones Province, only about 40km from the type locality of wagneri . A specimen was also seen, but not taken, at Rafaela, Santa Fe Province in March 2018.

Ríos & González (2011) mention that C. lecerfi might eventually be found in Paraguay since the material studied by Le Cerf was collected at Villa Lutecia, near San Ignacio, Misiones ( Argentina), close to the Paraná River. This locality is less than 10 km away from Itapúa Department ( Paraguay), so it is very likely that the species could live in the patches of Atlantic forest or grasslands from that Paraguayan region. This has now proved to be the case as the specimens of C. minerva were collected in Itapúa Department very close to the Argentine border.

One of us (SDR) recently collected a female (Fig. 16) in Paraguay on a cloudy day at 11:50 a.m. It was flying low among plants of Caraguatá, Bromelia sp., ( Bromeliaceae ), in a Chaco forest remnant associated with the salty lagoons south of Riacho Yacaré; its flight was slow and “heavy”. After a first attempt at capturing it, the specimen flew away but came back to the same plant. It is quite possible that it was trying to oviposit and the bromeliad may be the host plant. Overall, the moth resembles a miniature Castnia invaria .

A map with all known records is shown in Fig. 13 .

Material examined: 16 males and 5 females were examined for this study, although it should be noted that the sexes are difficult to separate and we have found many specimens in both institutional and private collections that have been mis-sexed. We have confirmed the sex for all specimens collected in 2017–2018 and the types of C. amalthaea and C. minerva in NHMUK; for all Argentinian specimens collected before 2018 we have relied on Penco (2011).

BRAZIL: 1♀ Holotype C. amalthaea , Brazil, Type, Castnia amalthaea type Druce, Brazil?, ex Stevens, Ex. Coll Herbert Druce, 1913, Joicey Bequest. Brit. Mus. 1934-120; PARAGUAY: 1♂ Holotype C. minerva, Puerto San Lorenzo , Itapúa, Paraguay, Type H.T., C. minerva Kruger 1926 Paraguay, Type R. Krüger, 53, 77-26, Joicey Bequest. Brit. Mus. 1934-120; 1♂ Paratype C. minerva, Puerto San Lorenzo , Itapúa, Paraguay, Type P.T., Einige Cotype R. Krüger, 54, 77-26, Joicey Bequest. Brit. Mus. 1934-120 (NHMUK); 1♀, Laguna Capitán, Presidente Hayes, Paraguay, 13.V.2017, Col. S. D. Ríos (MNHNPY); ARGENTINA: 1♂ Holotype C. wagneri, Républ. [ique] Argentine (Missions) Envir[ons]. de San Ignacio, Bords du Haut Parana, 1910, E.R. Wagner, Muséum de Paris, Holotype [red label], 7:2, Castnia wagneri Le Cerf Rev. Chil. de Hist. nat., 1911, vol. 15, p. 31 (P. Viette 8.1955) (MNHN); 1♂, Coll. Breyer, Rep. Argentina, [La Rioja], Patquia, no date, Alotipus [red label]; 1♀, Santiago del Estero, Rio Salado, no date, Wagner Leg.; 1♀ [?], Argentina, Formosa, Gran Guardia, XI-1952, Coll. Breyer (MLPA); 1♀, La Rioja, Mascasín, 2-III-1960, Leg. M. Zelich ( Castnia wagneri ) (MZ); 1♂, idem (TP); 2♂♂, Laprida, Choya, Santiago del Estero, Argentina, 30-50 masl, II-2018, Leg. A. Borquez (DC); 5♂♂, idem (MS); 2♂♂, idem; 2♂♂, Route 105, Pindapoy Grande, Misiones, Argentina, 100-150 masl, III-2018, Leg. A. Borquez (RW).

The genus Castnia s.s. will be dealt with in a future paper where more detail will be given about these taxa, but the synonymy for the species is given below:

Castnia Fabricius, 1807 (type species: Papilio icarus Cramer, 1775 ) amalthaea ( H. Druce, 1890) comb. rest. amalthaea—Castnia amalthaea H. Druce, 1890 wagneri—Castnia wagneri Le Cerf, 1911 (JH of wagneri Buchecker, [1880] ) (JSS) lecerfi—Castnia lecerfi Dalla Torre, 1913 (JSS) syn. nov. minerva—Castnia minerva R. Krüger, 1926 (JSS) syn. nov.

JH Junior homonym

JSS Junior subjective synonym

Figures

FIGURE 13. Distribution map of all known collecting localities of Castnia amalthaea, collected and identified as any of its synonyms. Black dots represent collected specimens, the open circle represents a sighting. Note: the type locality of C. amalthaea could be anywhere in southeast Brazil, so is not included (map prepared by Bolívar R. Garcete, MNHN Paraguay).

FIGURES 1–12. Castnia amalthaea H. Druce, 1890, Figs. 1, 2: ♀ holotype, C. amalthaea, “Brazil” (Courtesy NHMUK); Figs. 3, 4: ♂ holotype, C. wagneri Le Cerf, 1911, Misiones, Argentina (Courtesy MNHN); Fig. 5: ♂, C. amalthaea, Patquia, Argentina (Courtesy MLPA); Fig. 6: ♂, C. amalthaea, La Rioja, Argentina (Courtesy TP); Fig. 7: ♂ holotype, C. minerva R. Krüger, 1926, Paraguay (Courtesy NHMUK); Fig. 8: ♂ paratype, C. minerva, Paraguay (Courtesy NHMUK); Fig. 9: ♀ [?], C. amalthaea, Formosa, Argentina (Courtesy MLPA); Fig. 10–12: ♂♂, C. amalthaea, Santiago del Estero, Argentina, (RW collection). Scale: 10 mm.

FIGURES 14–15. Habitat of Castnia amalthaea in the Gran Chaco, Argentina. Note that the forest is a generally open, scrubby area. (Photos: Alejandro Borquez & Carlos Calderón). Figure 16: C. amalthaea resting on leaf of Caraguata, Bromelia cf. serra (Bromeliaceae), chaco forest remnant, Departamento de Presidente Hayes, Paraguay (Photo: Sergio D. Ríos).