Argyria lacteella (Fabricius, 1794)

Landry, Bernard, Bilat, Julia, Hayden, James, Solis, M. Alma, Lees, David C., Alvarez, Nadir, Leger, Theo & Gauthier, Jeremy, 2023, The identity of Argyria lacteella (Fabricius, 1794) (Lepidoptera, Pyraloidea, Crambinae), synonyms, and related species revealed by morphology and DNA capture in type specimens, ZooKeys 1146, pp. 1-42 : 1

Argyria lacteella (Fabricius, 1794)

Figs 3 , 4 , 5 , 6 , 7 , 11 , 17 , 24 , 27 , 29 , 33

Tinea lacteella Fabricius, 1794: 313. Type locality: " Americae insulis " (USA Virgin Island of Saint Croix; see Remarks). Fernald 1896: 72, plate V figs 4, 6; Dyar 1903: 411; Grossbeck 1917: 126, probably referable to A. gonogramma , see Remarks; Schaus 1940: 400; Amsel 1956: 31, pl. 69 fig. 6, part of records, misspelled ' Tinea lactella '; Munroe 1956: 127; Błeszyński and Collins 1962: 214; Zimsen 1964: 579, misspelled ' Tinea lactella '; Kimball 1965: 234, part of records; Błeszyński 1967: 96; Jaume 1967: 2; De la Torre y Callejas 1967: 20; Alayo and Valdés 1982: 61; Tan 1984: 96 et seq., misidentification; Ferguson et al. 1991: 40, misidentification; Munroe 1995 a: 35; Heppner 2003: 288, part of the records; Martinez and Brown 2007: 81, fig. 9, referable to A. gonogramma ; Roque-Albelo and Landry 2010; Scholtens and Solis 2015: 54; Landry et al. 2020: 101, fig. 6B; Gibson et al. 2021: 29.

= Pyralis albana (Fabricius, 1798 ( Pyralis ). Unnecessary replacement name.

= Zebronia abronalis Walker, 1859: 969 ( Zebronia ??). Type locality: Brazil, Rio de Janeiro.

= Catharylla lusella (Zeller, 1863: 51) ( Catharylla ). Type locality: St. Thomas Island [USA Virgin Islands]. Syn. rev.

= Argyria vestalis Butler, 1878: 494, 495. Type locality: Jamaica. Syn. nov.

= Argyria multifacta Dyar, 1914: 317. Type locality: Panama, Porto Bello. Syn. nov.

Type material examined.

Lectotype of Tinea lacteella (Fig. 3 ), here designated, with label data as follows: 1- "P. albana | ex Ins: Amer: |?Schmud?", 2- "Mus[eum]. S[ehested] & T[oender] L[und], 3- "LECTOTYPE | Tinea lacteella | Fabricius, 1794 | Des[ignated] by B. Landry, 2021"; deposited in ZMUC.

Holotype of Zebronia ? Zebronia abronalis (Figs 4 , 24 ), with label data as follows: 1- “Type”, 2- “Rio”, 3- “91”, 4- "Zebronia | Abronalis", 5- "TYPE LEP: No 1195 | Zebronia? | abronalis | Walker | HOPE DEP[ARTMEN]T.OXFORD"; deposited in OUMNH.

Holotype of Catharylla lusella (Fig. 5 ), with label data as follows: 1- “Type”, 2- Lusella | Zell[er]. Mon[ograph]. p.51.", 3- Zell[er]. Coll[ection]. | 1884.", 4- "♂ | Pyralidae | Brit.Mus. | Slide No. | 7092" | DNA voucher Lepidoptera B. Landry, no 00158 | NHMUK013696754 | MOLECULAR 215427977; deposited in the NHMUK.

Holotype of Argyria vestalis (Fig. 6 ), with label data as follows: 1- “Type”, 2- "Jamaica | 78. 19", 3- ♂ | Pyralidae | Brit.Mus. | Slide No. | 7093 | NHMUK013696753"; deposited in the NHMUK.

Holotype of Argyria pusillalis variety Argyria multifacta (Fig. 7 ) with label data as follows: 1- "PortoBello | Pan[ama]. Febr[uary]. [19]11 | AugustBusck", 2- "Type | No.16316 | U.S.N.M.", 3- "Platytes | multifacta | Type Dyar", 4- "♀ genitalia | slide 3826 | R W Hodges", 5- "Genitalia Slide | By RWH ♀ | USNM 10,709"; deposited in the NMNH. Paratypes of Argyria pusillalis variety Argyria multifacta with label data as follows: 1 ♂: 1- "PortoBello | Pan[ama]. Febr[uary]. [19]11 | AugustBusck", 2- "♂ genitalia | slide, 29 Apr. '32 | C.H. #29 | Genitalia slide | By ME ♂ | USNM 99,668"; 1 ♀: same data; 5 ♀♀, 2 ♂♂: same data except “Mar[ch]”; 2 ♀♀: 1- "RioTrinidad | Mar[ch]. [19]12 Pan[ama] | ABusck | coll"; 1 ♂: 1- "CorazolC[anal]Z[one] | Pan[ama] 3/24 [19]11 | AugBusck", 2- "♂ genitalia | slide, 9 June. '32 | C.H. #83" [slide not found]; deposited in the NMNH. [Note: the Tabernilla (Busck) and Corazol (Crafts) specimens were not found at NMNH]

Other specimens examined.

238 specimens (see Suppl. material 2).

Morphological diagnosis.

This is a small satiny white moth of 9.5-14 mm in wingspan. The forewing brown markings are median triangles on the costa and dorsal margin usually linked by a thin straight line sometimes slightly thicker on the discal cell as a spot, but sometimes inconspicuous, another triangle subapically on costa, usually separated by a thin white line from a short oblique dash anteriorly, and a wavy terminal line (Figs 3 - 6 , 11 ). There are also specimens of A. lacteella with a complete median fascia (Fig. 7 ) in the South of the distribution of the species, in Panama (holotype of synonym A. multifacta ), French Guiana, Bolivia, and Brazil. In forewing markings A. lacteella differs from A. gonogramma (Figs 8 , 12 ), which usually has a well-marked darker, blackish-brown spot on the discal cell, linked by a thin, curved line to a short diagonal bar on costa and a thin triangle on the dorsal margin, and without a clear costal triangle subapically. In forewing markings A. lacteella is most similar to A. centrifugens (Fig. 10 ), which is generally bigger (14-19 mm in wingspan) and which has the line anteriad to the subapical costal triangle curved to reach the costa at right angle whereas that line in A. lacteella runs obliquely into the costa. In male genitalia (Fig. 17 ) this species differs from the most similar A. gonogramma by the basal projection of the valva that is slightly longer and bent mesad at right angle whereas it is just barely curved in A. gonogramma (Figs 16 , 18 ). The cornuti on the vesica also are smaller and thinner in A. lacteella compared to those of A. gonogramma . In female genitalia A. lacteella (Figs 24 , 27 ) is also most similar to A. gonogramma (Fig. 28 ), but A. lacteella has two “pockets” anterolateral of the ostium bursae, whereas A. gonogramma has one continuous pocket anterior of the ostium.

Molecular results.

Phylogenetic inference based on COI barcode alignment reveals a large clade grouping the A. lacteella samples. This clade is relatively homogeneous since the percentage of divergence within this species remains low with an average of 1.25% (Fig. 2 ). It is then divided into two clades also identified by the species delimitation approaches. The first one is mainly composed of samples from South America, i.e., Brazil, French Guiana, Argentina, Colombia, but also from the Galapagos Islands. The different intraspecific delimitations identified by the species delimitation approaches within this clade are therefore certainly related to geographical divergence. The historical samples originating from Panama and the United States Virgin Islands belong to this clade as well. The barcodes of these samples are not complete (Table 1 ), the missing may induce phylogenetic artefacts due to long-branch attraction. A molecular analysis focused on this species including more localities but especially more loci could clarify this situation. The second cluster is composed of a clade of samples from the US on one side and a very large clade of samples from Costa Rica on the other. The latter shows a very low level of variation.

Distribution.

Widespread in the Western Hemisphere from the US State of Florida north to Alachua County in the north, across Central America and the Antilles, in South America to Argentina in the south, as well as on the Galápagos Islands (Fig. 33 ).

Remarks.

Fabricius (1798) changed the name of his Tinea lacteella (1794) with another ( Argyria albana ). The reason for this is unrecorded and remains unclear, but this is possibly because Fabricius (1798: 476, spelling it " Tinea lactella ") incorrectly considered Tinea lacteella to be a homonym of Tinea lactella Denis & Schiffermüller, 1775 (a synonym of Endrosis sarcitrella (Linnaeus)). Also, he may have corrected ‘improper’ names as in his treatments of Tinea compositella Fabricius, 1794 and T. tapetzella Linnaeus, 1758, both without putative ‘homonyms’ and respectively renamed Pyralis composana and P. tapezana (Fabricius, 1798: 480), or he felt that the exact orthography of any name was not so important.

The first label associated with the lectotype of A. lacteella (Fig. 3 ) reads "P[yralis]. Argyria albana | ex Ins. Amer: | Schmidt". The second line of this label means "from the American Islands" while the name of the third line refers to the collector of the specimen, who, according to Zimsen (1964) was either Adam Levin Smidt, a custom-house officer, or Johan Christian Schmidt, a surgeon. Both lived on the island of St Croix, which was at that time a Danish possession (T. Pape, pers. comm. to BL, 18 August 2022). The second label associated with this type specimen refers to the collection of Ove Ramel Sehested and Niels Tønder Lund who lived in Copenhagen and were pupils and friends of Fabricius ( Baixeras and Karsholt 2011).

The locality of origin is an additional complication associated with A. lacteella . The locality of Fabricius’ Pyralis albana (1798) is mentioned as " Americae insulis " [American islands] whereas that of A. lacteella (1794) is " Americae meridionalis arboretis " [South American arboretum]. Given that "Dr. Pflug" is mentioned in the original description of A. lacteella , it is reasonable to conclude that " Americae insulis " was a correction for " Americae meridionalis arboretis ". This is because Paul Gottfrid Pflug (1741-1789), a medical doctor, lived in the Caribbean island of Saint Croix (United States Virgin Islands) during the last five years of his life, where he collected insects that he sent to Denmark. He is mentioned often by Fabricius as a specimen collector (O. Karsholt, pers. comm. to BL, 3 June 2021). Therefore, A. lacteella / Argyria albana is from an American island ( Americae insulis ) that is probably Saint Croix.

As confirmed by Copenhagen Museum former curator Ole Karsholt and present curator Thomas Pape, only one type specimen presently exists for Americae lacteella / Americae albana (Fig. 1 ) and because Americae albana is best considered as an unjustified replacement name, the type of Pyralis albana Fabricius, 1798 is the same as that of Tinea lacteella Fabricius, 1794. This specimen is without an abdomen and is designated as the lectotype upon the recommendation of curator T. Pape, who wrote (pers. comm. to BL, 7 June 2021): "As Fabricius does not indicate the number of specimens, I would consider a lectotype designation as appropriate, unless this has already been done by referring to this specimen as "the type" or something similar." Such a designation also serves to stabilise the identity of the species name laden with confusion caused by Fabricius himself.

The type specimen of A. lacteella (Fig. 3 ) is badly rubbed, lacking most scales on the head, and some on the thorax and forewings as shown by the denuded anal vein on the right forewing. It also lacks most of the diagnostic brown markings of the forewing, notably the subapical triangle on the costa, but the terminal zigzagging brown line is almost complete and there are a few brown scales in the position of the median spot and fewer brown scales still on the dorsal margin medially.

Munroe (1995: 35) stated that Argyria abronalis is a nomen dubium, but this is incorrect as a female type (Figs 4 , 24 ) is in the Oxford University Museum of Natural History (also figured at https://www.oumnh.ox.ac.uk/collections-online#/item/oum-catalogue-3393). The forewing markings, female genitalia morphology and DNA barcode all concur to validate the synonymy of A. abronalis with A. lacteella . The species was described from the female sex, without indication or indirect evidence of more than one specimen; therefore, the OUMNH specimen is considered the holotype.

The original description of Catharylla lusella Zeller (1863) explicitly mentioned one female only, described from the island of Saint Thomas, US Virgin Islands. Thus, the male sign on this holotype’s slide number label is incorrect (Fig. 5 ). The specimen was dissected and although the genitalia dissection was not thoroughly cleaned, the visible morphological characters agree with those of A. lacteella . The forewing markings lack the median triangle of the dorsal margin and any indication of a median transverse line, as in the holotype of A. lacteella , but the subapical triangle on the costa and especially the COI barcode obtained clearly show that C. lusella syn. rev., should be considered a synonym of A. lacteella . The name had been synonymised by Fernald (1896), considered a synonym also by Schaus (1940), but considered valid again by Błeszyński and Collins (1962) and Munroe (1995; misspelled " lusalla ").

The original description of Argyria vestalis does not mention more than one specimen and the NHMUK does not hold additional specimens with these label data; therefore, this specimen is considered the unique holotype. It is a lightly marked, damaged, dissected male (Fig. 6 ); the dissection clearly shows the curved projection at the base of the valva that is diagnostic for A. lacteella ; therefore, the name A. vestalis syn. nov. is considered a synonym of A. lacteella .

Argyria multifacta was described as a variety of A. pusillalis for which "All the specimens have the median band continuous across the wing" ( Dyar 1914: 317). Among a series of specimens mentioned from several localities in the Panama Canal zone, one is recorded as Type with the type number and label data mentioned above (Fig. 7 ). Although this holotype shows a conspicuous and almost continuous median band on the forewing, thus revealing strong variation in that respect in the species, other wing characters, size, and the COI barcode data point to the synonymy of A. multifacta syn. nov. with A. lacteella .

This species evidently became established in Florida, USA in the 1970s and consequently, earlier records from Florida ( Grossbeck 1917; Kimball 1965) are believed to be wrong and referable to A. gonogramma . The earliest specimen known to us was collected in Miami-Dade County, Fuchs Hammock near Homestead, by T.S. Dickel on 31 August 1979 (MGCL catalogue no. 1112898, slide 6219, deposited in FSCA). The species rapidly spread across the state, as shown by first collection years in other vouchered counties: 1983: Highlands, Monroe, Orange; 1986: Collier, Manatee; 1987: Volusia; 1988: Lee; 1990: Pinellas; 1991: Hernando; 2000: Brevard; 2003: Marion; 2005: Alachua; 2012: Indian River; 2013: Levy (FSCA, MGCL). The collection of A. gonogramma in Florida decades before A. lacteella strongly suggests that the latter species is non-native and that it invaded in the given time frame (see Remarks for A. gonogramma ).

Amsel (1956: 31, pl. 69 fig. 6) mentions the species from specimens sporting a wingspan of 12-18 mm, and although his illustration probably represents A. lacteella , no specimens examined of that species were found to reach a wingspan of more than 14 mm.

The vesica of a male specimen from Florida, USA (not illustrated here) was successfully everted by J. Baixeras, who wrote the following to BL on 17 October 2022: "After a lot of manipulation I was able to evert what seems like a rather tubular vesica bearing a single row of non-deciduous cornuti tightly arranged like in a "gun charger" mode. The vesica seems to be somewhat convoluted at the base (I do not think it an artefact), then straight. The cornuti are extended all over the length of the vesica except in the terminal part, close to the genital opening. The basal convolution is interesting and, if my surmise is correct, should be correlated with some structure in the female, either a pocket, broadening sclerotisation or, in some cases, some corrugated area allowing expansion during insertion." The basal convoluted bend at the base of the vesica reflects the shape of the basal section of the female ductus bursae, which is indeed corrugated (Figs 24 , 27 ).

Figures

Figure 1. Phylogenetic inferences including 174 Argyria COI barcode sequences, i. e., 160 barcodes from BOLD, 9 COI sequences amplified by PCR (in bold), and 5 COI sequences obtained using capture from historical specimens (in red). Nodal support expressed in SH-aLRT and ultrafast bootstrap (UFBoot) is given as indicated in the caption except for nodes when SH-aLRT <80 and / or UFBoot <95. Species delimitation results including morphology, ABGD, GMYC, and PTP are indicated by different colours to represent the species proposed.

Figure 2. Mean genetic divergence (p-distance) between all samples from each species.

Figure 3. Lectotype of Tinea lacteella Fabricius, 1794 (copyright of Natural History Museum of Denmark, ZMUC). Scale bar: 1 mm.

Figure 4. Holotype of Argyria lacteella synonym. Zebronia?? abronalis Walker, 1859 (Oxford University Museum of Natural History; OUMNH). Scale bar: 10 mm.

Figure 5. Holotype of Argyria lacteella synonym. Catharylla lusella Zeller, 1863 (NHMUK Trustees of the Natural History Museum).

Figure 6. Holotype of Argyria lacteella synonym. Argyria vestalis Butler, 1878 (NHMUK Trustees of the Natural History Museum).

Figure 7. Holotype of Argyria lacteella synonym. Argyria pusillalis variety Argyria multifacta Dyar, 1914 (NMNH; wingspan: 12 mm).

Figure 8. Habitus of Argyria type specimen (in NMNH) with labels underneath; holotype of Argyria gonogramma Dyar, 1915 (wingspan: 11 mm).

Figure 10. Habitus of Argyria type specimen (in NMNH) with labels underneath; holotype of Argyria centrifugens Dyar, 1914 (wingspan: 16 mm).

Figure 11. Habitus of additional Argyria specimen. Argyria lacteella (Florida, Putnam Co., FSCA). Scale bar: 2.5 mm.

Figure 12. Habitus of additional Argyria specimen. Argyria gonogramma (Florida, Seminole Co., MHNG). Scale bar: 2.5 mm.

Figure 16. Male genitalia of Argyria gonogramma holotype (NMNH). Close-up of bases of valvae with tip of phallus in middle.

Figure 17. Male genitalia of Argyria species. Argyria lacteella (Florida, Alachua Co.). In FSCA. Scale bar: 500 µm.

Figure 18. Male genitalia of Argyria species. A. gonogramma (Florida, Wakulla Co.). In FSCA. Scale bar: 500 µm.

Figure 33. Distribution of Argyria lacteella (Fabricius).

Figures 24 - 26. Female genitalia of Argyria species 24 Argyria lacteella (holotype of A. abronalis, with spermatophore inside corpus bursae; OUMNH) 25 A. diplomochalis (Anguilla Island, BL 1889, CMNH) 26 A. centrifugens (Colombia, Amazonas, Leticia, MHNG-ENTO- 97427). Scale bars: 250 µm (24), 500 µm (25, 26).

Figures 27, 28. Female genitalia of Argyria species with ultimate segments cut dorsomedially from base to apex 27 Argyria lacteella (USA, Florida, Glades Co.) 28 A. gonogramma (USA, Florida, Orange Co.). Both in FSCA. Scale bar: 250 µm.

Figures 29 - 32. Heads of Argyria specimens 29 A. lacteella (USA, Florida, Pinellas Co.) 30 A. gonogramma (USA, Florida, Levy Co.) 31 A. diplomochalis (US Virgin Islands, St Croix) 32 A. centrifugens (Colombia, Amazonas, Leticia). All in MHNG. Scale bars: 250 µm (29 - 31), 500 µm (32).