Research Article |
Corresponding author: Mark J. Sterling ( m.sterling@nhm.ac.uk ) Academic editor: Jadranka Rota
© 2024 Mark J. Sterling, Daisy T. Cadet, Jordan Beasley, David C. Lees.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Sterling MJ, Cadet DT, Beasley J, Lees DC (2024) A success for community science: Carmenta brachyclados sp. nov. (Lepidoptera, Sesiidae, Synanthedonini), a clearwing moth from Guyana discovered with its hostplant indoors in Wales (United Kingdom). Nota Lepidopterologica 47: 201-218. https://doi.org/10.3897/nl.47.130138
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A new species of Sesiidae, Carmenta brachyclados Sterling & Lees, 2024 is described from adult specimens, pupal exuviae and larval borings which were accidentally transported to South Wales, United Kingdom. DNA barcoding and morphological evidence shows that this species is native to the Neotropics, where it feeds in the seedpods of the leguminous tree, Mora excelsa Benth. (Fabaceae: Caesalpinioideae) and that it is related to a group of seed-feeding species of clearwing moths within the genus Carmenta Edwards, 1881, naturally occurring in the Neotropics and southern Nearctic, although C. mimosa Eichlin & Passoa, 1984 has been introduced in Australia and elsewhere as a biological agent.
Whilst in Guyana, local people told my mother, Ashleigh Cadet, that if she left an offering of tobacco to the jungle spirits, she would be shown something beautiful from the jungle, so that is what she did - DTC.
Ashleigh Cadet, a professional photographer and the mother of DTC, lives in Port Talbot, South Wales. Port Talbot is more famous in the United Kingdom for its steelworks than its clearwing moths. However, on 4 February 2024 DTC (who is not a lepidopterist) spotted an insect flying at a window in the house which she shares with Ashleigh. On closer inspection there was a similar but dead specimen on the windowsill. DTC posted an image of the live specimen on Instagram (Fig.
As DTC had found a live specimen, MJS and DCL sent DTC some images of larval workings and pupal exuviae of clearwing moths and suggested she search the plants in the house. Unknown to MJS and DCL, this was no mean task as both DTC and Ashleigh are keen plant growers, but a careful search and identification of some 85 living indoor pot plants and any remaining cut flowers which could be found produced no obvious sesiid hostplants and no exuviae. The live specimen had died in the fridge, but DTC brought both specimens, still in good condition, to the NHMUK for identification. Both specimens were promptly DNA barcoded by the third author (JB). The results suggested that they belonged to the genus Carmenta Edwards, 1881, a large genus of Sesiidae distributed throughout the Americas and that they belonged to an apparently seed boring group from central America/the northern part of South America.
This finding was a lightbulb moment. Ashleigh had returned (on 18 October 2023) from a photographic assignment in Guyana. In a corner of the room in which the specimens had been found lay Ashleigh’s boot bag, back from the trip. DTC carefully searched the boot bag and in debris and dried mud at its bottom found two pupal exuviae, both almost intact (Figs
The fragment and the exuviae were carefully preserved by DTC and sent to the NHMUK. Examination of two potentially still capped tunnels revealed nothing more inside. The fragment was shown by DCL and MJS to Dr Sandra Knapp (NHMUK) who immediately suggested that it was part of a seedpod and even suggested a genus for it (correctly as it proved). This raised the possibility that the plant fragment could itself be identified by DNA barcoding using plant primers.
Carmenta is a genus which is almost exclusively known from the Americas. This paper represents what appears to be the first record of the genus Carmenta from Europe or the UK (albeit accidentally imported without release into the wild). Outside the Americas, the genus is known from Australia, Indonesia, Malaysia, Thailand, Vietnam and Hawaii, where Carmenta mimosa Eichlin & Passoa, 1984 has been introduced as a biological control for the invasive leguminous weed, Mimosa pigra L. (Paynter, 2005). In Central and South America a few species of Carmenta have pest status, notably C. foraseminis Eichlin, 1995 which infests cocoa pods (Theobroma cacao L.) (Harms and Aiello 1997;
The present description of a new species follows a comparison by the naming authors of the specimens to the described species of Carmenta and to other sesiid materials at the NHMUK and on BOLD.
The adult specimens of the new taxon belonging to Sesiidae (hereafter ‘the mystery clearwing’) were obtained indoors in South Wales. The mystery clearwing specimens were relaxed in a chamber containing water and a few drops of glacial acetic acid and set at the NHMUK, after legs had been removed from each specimen for DNA barcoding. They were then compared to the collection of Sesiidae at the NHMUK (including supplementary collections and accessions). In addition, following the results of DNA barcoding, which showed that almost all the specimens identified to species level in the top 99 hits in the BOLD identification engine (https://boldsystems.org/index.php/IDS_OpenIdEngine) were species of the genus Carmenta, the mystery clearwing was also compared to all described species currently placed in Carmenta. A checklist of these described species was prepared from
For these species, the original description was located and compared to the mystery clearwing. Type specimens and (if dissected) their genitalia were examined if these were held at the NHMUK. In other cases, an image (of the type (female allotype or syntype where possible) was also compared to the mystery clearwing. The genitalia of two female specimens of Carmenta cf. whitelyi were compared to those of one of the mystery clearwings (slide number NHMUK014332461) and, in the case of C. theobromae, a non-type specimen and images of further non-types were compared.
The process for comparing the mystery clearwing to the shortlisted Carmenta species is set out in Suppl. material
The two sequences from the two sesiid specimens are identical. One of the sequences (for NHMUK013700463) was queried on BOLD (on 23/02/2024). A neighbor joining (NJ) tree was constructed, and minimum p-distances were calculated between the query sequence and nearest neighbours using 100-Identity. We then downloaded all available BINs identified as Carmenta with GenBank accessions from BOLD (on 5/05/2024), together with those identified as Alcathoe, Hymenoclea, and Penstemonia (following the results of the phylogenetic analysis of Cognato et al. (2023)) and ran the query sequence with them using default options in Phyml 3.0 (online; http://www.atgc-montpellier.fr/phyml/execution.php), including the model selected by Bayesian Information Criterion (GTR + R model favoured) and ABayes support.
The fragment of plant material was shown to Dr. Sandra Knapp for an approximate identification, and she immediately suggested part of the seedpod of the legume genus Mora R.H. Schomb. ex Benth. (1839). DNA barcode sequences were subsequently extracted as follows.
A small fragment (<1 cm) of seed was prepared for extraction by grinding in liquid nitrogen with a pestle and mortar. Half of the resulting powder was then used for DNA extraction with a cetyltrimethylammonium bromide (CTAB) extraction (DOI: https://dx.doi.org/10.17504/protocols.io.e6nvw157zlmk/v1). Purified DNA was quantified by nanodrop. Three regions were used to generate DNA barcodes, rbcL, matK and ITS2 (Table
DNA barcoding region | Primer name | Sequence 5’–3’ |
---|---|---|
ITS2 | ITS3 | GCATCGATGAAGAACGCAGC |
ITS4 | TCCTCCGCTTATTGATATGC | |
MatK | MatK_1R_kim | ACCCAGTCCATCTGGAAATCTTGGTCC |
MatK-3FKIM-r | CGTACAGTACTTTTGTGTTTACGAG | |
rbcL | rbcLa-F | ATGTCACCACAAACAGAGACTAAAGC |
rbcLa-R | GTAAAATCAAGTCCACCRCG |
PCRs were performed using the KAPA Plant PCR kit in 25 µl reaction volumes comprising 12.5 µl KAPA Plant PCR buffer, 4.8 µl nuclease free water, 1 µl 25 mM MgCl2, 0.75 µl 10 µM forward primer, 0.75 µl 10 µM reverse primer, 0.2 µl polymerase and 5 µl DNA template. The following thermocycling protocol was used: 20 s at 95 °C for initial denaturation, followed by 35 cycles of 20 s at 95 °C for denaturation, 15 s at 55 °C for annealing, 20 s at 72 °C for extension, and 1 min at 72 °C for the final extension. PCR amplicons were visualised on a 1% agarose gel and quantified by Qubit. Amplicons were pooled for library preparation with the Oxford Nanopore Ligation Sequencing kit (v14) and sequenced on a Flongle (v10.4.1). Resulting reads were aligned and consensus sequences generated using Geneious (v2023.0.4). For MatK, the final sequence was a consensus of 393 fragments; for rbcL, 259; and for ITS2, 100.
We used Phyml 3.0 (online) to run the final query sequences (MatK, 686 bp; rbcL, 599 bp) as part of an alignment including all genera found in the
The illustrated material, other than Fig.
Description of the external features of the new taxon follows
Accession numbers and other data for sequences used in all trees (Figs
The initial query of the mystery clearwing (NHMUK013700462) on BOLD resulted in a 5.66% p-distance to the nearest hit (“Carmenta sp. lep131”, representing Barcode Index Cluster [BIN] BOLD:ABV2191). Only DNA barcodes identified as the genus Carmenta appeared in the top 50 hits with a maximum of 10.4% p-distance. In all there were 244 sequences identified to the genus Carmenta representing 52 identified species with 72 BINs publicly available on BOLD (on 16/08/2024). Following branching patterns in the resulting NJ tree, NHMUK01370046 was 6.57% p-distant to both C. guyanensis from French Guiana (BOLD:AAM7091) and a species from Costa Rica (BOLD:AEF7752), 7.07% p-distant to another species from Costa Rica (BOLD:AET8297), 7.34% p-distant to sp. lep111SG from Panama (BOLD:ABV4214), 8.97–9.22% p-distant to BOLD:AAK2798 (variously identified as C. surinamensis, C. foraseminis and C. theobromae), and 10.09–10.22% p-distant to C. foraseminis (BOLD:ABV2190).
The mystery clearwing clearly fitted with the genus Carmenta from a DNA barcode perspective (Fig.
Adding in available BIN cluster representatives downloaded from BOLD (on 5/05/2024) and running again in Phyml 3.0 (online) resulted in Fig.
For the plant DNA barcodes, Blast results (https://blast.ncbi.nlm.nih.gov/Blast.cgi) for the seedpod fragments Matk showed a perfect match of 100% with Mora excelsa Benth. (KX538501), a 99.71% match with M. gonggrijpii (Kleinhoonte) Sandwith (KX538485, EU362005), a 98.98% match with Stachyothyrsus staudtii Harms (JX099332), and a 98.69% match to Dimorphandra conjugata (Splitg.) Sandwith (EU361934).
The Phyml tree for the Matk marker (Fig.
Phylogenetic tree using Phyml 3.0 of the DNA barcode of the holotype of the new taxon (NHMUK013700462) run with DNA barcodes of representative BIN clusters for the other 40 publicly available BINs of Carmenta spp. Supports shown on nodes are ABayes measure in Phyml 3.0 (see Methods), with a minimum of 0.95 being considered significant for the purposes of this analysis. The clade subtended by C. mimosa, which includes the new taxon, is highlighted in light blue. The tree was rooted in FigTree using three representatives of the genus Synanthedon including the type species S. tipuliformis and publicly available BINS of three other genera (Hymenocloa, Penstemonia and Alcathoe, highlighted in pink) likely to be internal to Carmenta (see Methods). The accompanying image is the ventral surface of the holotype of the new taxon prior to relaxing and setting.
The generic characters for Carmenta are: ductus bursae sclerotized on at least ½ its length for most species; ductus seminalis arising midway between posterior end and corpus bursae or nearer the latter in most species; most species without signum on corpus bursae (
The morphological results at the specific level are set out in Suppl. material
Phylogenetic tree using Phyml 3.0 showing the position of the DNA barcode of the holotype of the new taxon (NHMUK013700462) in the context of likely seed-boring Neotropical sesiids and focusing on host associations, which are a subclade of the light blue highlighted clade in Fig.
Phylogenetic tree for the Matk marker using Phyml 3.0 and including a sequence of the seedpod fragment (in red) and for of all genera found in the
Phylogenetic tree for the rbcL marker including sequences of the seedpod fragment (in red) and of all genera found in the
The type(s) of Sesia surinamensis Möschler, 1878 are described as lost in
For Carmenta benoisti and C. flavostrigata there are substantial differences between photographic images of the types and the drawings of those types on the one hand and the unknown specimens on the other.
C. theobromae is, as mentioned above, a pest species on Cacao. Although we have not been able to review an image of the type specimen, the mystery clearwing specimens are different in physical appearance from the non-type specimen in the NHMUK collection and the images we have reviewed in the pest literature and various other sources. As stated above, DNA barcode data show confusion between C. surinamensis, C. theobromae, and C. foraseminis, so identities in the pest literature should be taken with caution.
Holotype • ♀, wingspan 18 mm, fwl 8 mm, Central Guyana, ex seedpod fragment Mora excelsa (det. DNA barcode), accidentally collected ca. 12.x.2023 (leg. Ashleigh Cadet) and transported to United Kingdom, adult found live indoors, Wales, Neath, Port Talbot, 04.ii.2024, leg. Daisy T. Cadet, specimen number NHMUK013700462, accession number BMNH(E) 2024-18. Paratype • ♀ same collection data as holotype except found dead in house, specimen number NHMUK013700463, slide number NHMUK014332461. The types have been deposited at the NHMUK (see also Associated material not individually linked to each type).
Hindwing with branch of M3 and CuA1 very short (1/10th of distance between edge of discal cell and termen), forewing with discal spot narrow and tapering below M3 towards dorsum, exterior transparent area elongate, with moderately convex outer margin, apical area predominantly black, reaching close to branch of R4 and R5, entire area between stalks of R4 and R5 scaled black (Figs
Female (Figs
Male. Unknown.
Female genitalia (Fig.
Two larval tunnels filled with a mixture of frass and silk were found between the two lignified surfaces of a fragment of seed pod of the leguminous tree Mora excelsa Benth. The pupal exuviae of one of the specimens is illustrated at Figs
Central Guyana. Accidentally transported to UK without release in the wild.
The specific name is derived from brachys (gr.) short; klados (gr.) a branch. The species is named after the characteristic short branch of M3 and CuA1 in the hindwing.
Hostplant voucher (Mora excelsa pod fragments): NHMUK013700486. Pupal exuviae of Carmenta brachyclados females: NHMUK013700484, NHMUK013700485 (these were not readily matchable to specific types and so have separate object numbers).
A comparison of data on similar species of Carmenta to C. brachyclados is available in Suppl. material
The closest taxa to C. brachyclados are C. whitelyi and a taxon we refer to (without describing) in this paper as C. cf. whitelyi. However, in C. whitelyi the branch of M3 and CuA1 in the hindwing is longer (1/5 distance between the edge of the discal cell and the termen) whereas in C. brachyclados it is shorter (1/10th of the distance between the edge of the discal cell and the termen). Also, in the forewing of C. whitelyi, the discal spot is broader and hardly tapers towards the dorsum and the exterior transparent area is subquadrate and comparatively narrow, with an almost straight outer margin, whereas in C. brachyclados, the discal spot is narrower and tapering below M3 towards the dorsum, the exterior transparent area is elongate, and its outer margin is strongly convex (Figs
In C. cf. whitelyi the branch of M3 and CuA1 in the hindwing is a similar length to that of C. whitelyi, the discal spot is broader than in either C. brachyclados or C. whitelyi and the exterior transparent area is elongate, with the outer margin less convex than C. brachyclados (see Suppl. material
The NHMUK collection has 5♂ and 12♀ which we have identified as C. cf. whitelyi, including eight specimens collected by Herbert Simpson Parish on 29.vi.1901. Existing DNA barcodes and other similar material in the NHMUK collection, including a large number of Le Cerf manuscript types, indicate that there is a complex group of similar species, and that this taxon is best described as part of a comprehensive review of that group.
The updated ICZN Code states that the type locality of a nominal species-group taxon is the geographical place of capture, collection or observation of the name-bearing type (Article 76.1). However, if capture or collection occurred after transport by artificial means, the type locality is the place from which the name-bearing type began its unnatural journey (Article 76.1.1) and this is our case. DNA analysis of the adults and the plant fragment, together with timing of emergence compared to Ashleigh’s work itinerary, point to the origin of the holotype in Guyana although the exact location is unclear. Aside from some savannah sites unlikely to constitute localities for Mora excelsa within the upper Rio Takuto, Tapunini and Upper Demerara - Berbice regions, Ashleigh’s work in Guyana took her to a number of other sites in Upper Essequibo and Potaro-Siparuni. The Essequibo and Siparuni Rivers border the Iwokrama forest and Turtle Mountain range, sites that she visited, and she photographed a few large buttresses that might belong to M. excelsa near Iwokrama River Lodge on 12/10/2023. These regions are in the central part of Guyana (Fig.
Carmenta brachyclados sp. nov.; 11. Holotype ♀ dorsal; 12. Holotype ♀ ventral; 13. External diagnostic characters of C. brachyclados; 14. External diagnostic characters of C. whitelyi; 15. Paratype of C. brachyclados ♀ genitalia slide number NHMUK014332461; 16. Paratype of C. brachyclados pre-genital abdomen. Scale bars: 10 mm (11, 12, 16); 1 mm (15).
Fig.
Map of Guyana showing the most likely sampling positions (white circles: Turtle Mountains and Iwokrama Forest/Iwokrama River Lodge) for the seedpod of Mora excelsa with the two live pupae of Carmenta brachyclados inside. Credit: Google Earth/Landsat/Copernicus/Rivers_Guyana.mkl/Guyana regions english.png (CC by 2.5).
Harms and Aiello comment that, given that many, perhaps most, fruits and seeds are eaten by ground-foraging mammals (e.g., agoutis, squirrels, and peccaries) soon after falling, one would expect that individuals remaining in fallen fruit soon would be eaten or buried by mammals (
The fragment of seedpod we have examined shows that the larva of C. brachyclados, at least in its latter stages, bores between the hardened surfaces of the seed pod. This part of the pod will be less nutritious than the fruits or seeds but perhaps this is a defensive adaptation against predation by small seed and fruit-feeding mammals. It would be interesting to explore whether this or other similar species feed in fruits and/or seeds in the early stages of their development but transfer to the hardened part of seedpods, for better protection against predation, in the latter part of their development. There are other potentially significant roles of seed boring sesiids in the ecology of tropical forests. We do not know what happened to the seed(s) contained within this pod (M. excelsa pods have only 1–2 seeds:
The genus Carmenta is exceptionally diverse, and there must be other undescribed species ready to discover in the Neotropics particularly (
It is rare for a species of micromoth and most unusual for a species of larger moth (as that term is commonly used in the UK) to be newly described from specimens found in the UK. The last time the latter occurred was with Thera britannica (Turner, 1925).
However, the increase in the prevalence of international travel, both for work and leisure purposes, increases the likelihood of potentially interesting and important data on the biodiversity of insect species being found in somewhat unlikely places (
Finally, prior to the development of pheromone lures, clearwing moths were notoriously difficult to find or rear, even by experienced lepidopterists (Zukowsky 1913: 1215). The chances of two clearwing moths from the Neotropics successfully emerging in South Wales, over three months after they arrived, from a small fragment of a seedpod of a tropical tree, accidentally stuck to the boot of a professional photographer, carried halfway round the world in a boot bag to a cold Welsh winter, and being preserved in good condition, together with their food source and pupal exuviae, seem highly remote. The jungle spirits were clearly with Ashleigh. It must have been very good tobacco.
We are grateful to Ashleigh Cadet for her patience in answering questions about the details of her work in Guyana. Many thanks also to Claire Griffin, Sequencing Assistant at the Natural History Museum London for her help in cryogenic grinding of seed material and providing the CTAB extraction protocol. We thank Dr. Sandra Knapp (NHMUK) for identifying the plant fragment as a piece of seedpod likely to belong to Mora sp. We thank Jacek Wajer (NHMUK) for kindly providing links to herbarium samples showing pods of M. excelsa. Théo Léger and Viola Richter of Museum für Naturkunde, Berlin are thanked for locating and photographing the syntypes of Sesia surinamensis Möschler, 1878. We are grateful to Dr Franz Pühringer for all his help, including permission to use the sequences for Carmenta guyanensis and C. surinamensis (Fig.
Supplementary table S1 and figures S1–S20
Data type: pdf
Explanatory note: Comparison of data on similar species of Carmenta to C. brachyclados.
Supplementary table S2
Data type: xls
Explanatory note: Accession numbers and other data for sequences used in Figs