Digitalisation of the type specimens of Lepidoptera (butterflies and moths) of the Royal Museum for Central Africa: before long the pictures on the web (by Ugo Dall'Asta and Frans Desmet).
Digitisation of Lepidoptera type material of the Royal Museum for Central Africa has been carried out with a Coolpix 990 digital camera. All primary types, as well as allotypes, were photographed. In the absence of the former two, a picture of a paratype (excluding Microlepidoptera, Pyraloidea and Lymantriidae) was taken. All labels were included on the photograph and the status of the type was checked with recent literature. These photographs, 4374 in total (of which 1498 primary types),will be available on the web early next year with information on synonymy and other data about the specimens.
Even today, biologists sometimes wonder why so much effort is carried out to keep natural history collections in good condition. One of the major reasons is that in many fields, these are the most important depository of information on organisms. Except for vertebrates and higher plants, finding the name of organisms can sometimes be a very difficult task. In zoology, this is mainly the case for invertebrates. Within this group, some organisms are better known like butterflies. In West-Europe, these can often be identified in the field even without capturing the specimen. However, such easy identifications remain an exception in invertebrates.
When switching to the tropics, even for a well known group such as the butterflies, identification becomes also difficult due to the vast number of species. In West-Europe, for example, there are a little less than 400 different butterfly and skipper species, but in the Afrotropical region (Sub-Saharan Africa including the surrounding islands), there are more than 4000 (Larsen, 2005). Within habitats, this diversity is also clearly seen, as for example on a single mountain, mount Fébé near Yaoundé (Cameroon), on which more than 700 different butterfly species were captured (Libert, pers. comm.). A second example is a degraded forest in Ivory Coast (Bossematié Forest, 20km south of Abengourou), an area of only 216 km², in which probably as many as 500 different butterfly species occur (Fermon, et al., 2000).
This difficulty in identification is of course even worse in other groups of tropical invertebrates, furthermore the literature on these organisms is scattered amongst innumerable publications. A practical example of identification of Afrotropical moths will be presented later in this paper. Because of all these difficulties, the easiest and most practical way of identifying specimens becomes comparing them with those of a well curated collection. This means that these collections of invertebrates are real identifications tools which are very often used by many scientists, not only for systematics, but also for biodiversity studies, finding of indicator organisms, faunistics, etc.
The specimens which are the most manipulated are of course the type specimens. They are the bearers of the scientific names and, in case of doubtful identifications, scientists always refer to them. In order to preserve this type material as much as possible, a program of digitisation was carried out to photograph these specimens.
The Royal Museum for Central Africa, located in Tervuren, was established in 1897 and is thus a fairly recent Museum. The entomology section is very large, it occupies 2000 m²,in total. The Lepidoptera collection, like all other insect collections of the section, is exclusively Afrotropical.
General view of the butterfly collection of the Royal Museum for Central Africa: a little less than half a million specimens housed in 197 cupboards in more than 4.000 drawers.
(photograph by San-Ho Correwyn)
In the early 20th century the Lepidoptera send to the Museum from Africa came chiefly from the former Belgian Colonies: the Democratic Republic of the Congo, Rwanda and Burundi. Today, still 75 % of the specimens are from these countries. Later, correspondents from Ghana, Kenya and Uganda sent quite a lot of specimens and, for these countries we have now also a good coverage of the species. All together, other countries, including South Africa, make up only a few per cent of the collection.
Through databasing of two families/subfamilies (Papilionidae & Charaxinae) it was possible to estimate the total number of specimens in the Lepidoptera collection: about 240,000 butterflies and skippers (Rhopalocera), and 230,000 macro- and micromoths (Heterocera). The collection of butterflies and skippers probably contains 75% of the nearly 4000 known Afrotropical species. Curation of the moths families revealed that the coverage for moths is much less: about 27% of the Noctuidae species and about 33 % of the Geometridae (two of the largest Afrotropical moth families) are represented out of the about 37 500 known Afrotropical species (Vane-Wright, 1997). All these collections are housed in 197 massive oak cupboards in more than 4000 hermetic boxes (Figure 1).
As mentioned before, the types are the most manipulated specimens and the digitisation programme was focused on them. The aim was to put on internet recto and verso photographs of type material. First of all of, the primary type (holotype, lectotype or neotype) was photographed.If available, the allotype (which is usually a specimen of the opposite sex) was also recorded. When no primary type or allotype were present, a paratypewas photographed. Since it is a tradition to deposit paratypes in sister museums, these specimens are, in modern Lepidopterology, nearly as valuable as primary types.
On the photographs, the recto and the verso of all or nearly all labels were included, as well as a small lath to have an idea of the expanse of the specimen (Figure 2).
Red : Cymothoe arcuata Overlaet (Nymphalidae), holotype recto.
Yellow : Bunaeopsis princeps aurata Rougeot (Saturniidae), holotype verso.
In this project, all types of Lepidoptera under the responsibility of the authors were photographed: the butterflies, the skippers and the macromoths.The Microlepidoptera and Pyraloidea (curated by others) as well as the Lymantriidae were not included. This latter family is now being revised and, when revision will be completed, the photographs of types will also be included.
Number of primary types, allotypes and paratypes if primary types are absent, of butterflies and skippers of the collection of the R.M.C.A.
|Family - Subfamily||Ht||At||Pt|
Although photographing the specimens proceeded rather quickly, a big drawback was the verification of the types.Doing this verification with the original literature would have been a monumental task, so we made the choice to do it with recent catalogues, if available (1960 and later). Luckily, there is a recent catalogue for butterflies and skippers (Ackery et al. 1995), and verification did not take too much time. Here follows the list of type material for this group in the collection of the R.M.C.A. (Table 1).
List of catalogues used to verify the type status of the Heterocera of the R.M.C.A. The family/subfamily names are the ones currently accepted in Lepidopterology, original references at the end of the paper.
|Family - Subfamily||Bibliography|
|Arctiinae||Watson & Goodger, 1995|
|Notodontidae||Kiriakoff 1964 & 1970|
|Sphingidae||Kitching & Cadiou, 2000|
Unlike the butterflies and skippers, there is no single catalogue for the Afrotropical moths. Even on the catalogue level, literature on moths is scattered in different journals and books. Those that were used for the verifications of the type material are listed in Table 2. Knowing that there are about 50 macromoth families, it is obvious that the coverage of this group in recent literature is far from complete.
When recent catalogues were not available, checking was done with older ones or information found the collection of The Natural History Museum, London. Table 3 shows the list of the numbers of primary types of macromoths at the R.M.C.A.
Number of primary types in the Heterocera of the R.M.C.A., excluding Microlepidoptera, Pyraloidea and Lymantriidae.
None the less, the authors were sometimes confronted with unsolvable problems. For example, two holotypes of a Saturniid species mentioned in recent catalogue could not be traced back through the zoological record and their label data could not be checked.
This shows once more the weakness of our actual state of the knowledge on African moths: only catalogues or revisions, all of them with very little illustrations, mainly in black and white, and illustrates the difficulties in identifying taxa in the absence of reliable collections.
The project of digitizing the type specimens started in January 2003 with a Nikon COOLPIX 990 digital camera. A first step was to calibrate this camera to the needs of the project. The automatic settings were unsatisfactoryand the following settings were used:
- Flash: off
- Focus mode: ‘macro close-up’
- Image quality: FINE (1.0-1.2 megabyte per photograph)
- Illumination: circular neon lamp, setting ‘fluorescent’ (submenu: +1+2+3) for Rhopalocera, and annular illumination,setting ‘cloudy’, submenu: -2-3 for Heterocera
When searching for the best settings to take the pictures, our policy was to focus on yellow, because when this colour is at its best, the others are also quite satisfactory. As background the most suitable colours seemed to be light blue or light grey.
Note that the Coolpix 990 is now bypassed by quite a number of more performing digital cameras.
During the period of January 2003 till February 2005 a total of 1498 primary types were photographed and their type status verified to the best of the author’s abilities. The total number of photographs taken, including secondary type material, is 4374, of which 2246 butterflies and skippers and 2128 macromoths (Table 4).
Number of photographs of butterflies and skippers taken for the digitalization project.
|Family - Subfamily||#Pictures|
Number of photographs of moths taken for the digitalization project, excluding Microlepidoptera, Pyraloidea and Lymantriidae.
The information about the photographs has been edited using Excel (because of the flexibility and ease of transfert of this software). The fields used in the excel file were:
| Code | Family | Subfamily | Genus | species | subspecies | form | author | comments | HTrecto | HTverso | ATrecto | ATverso | PTrecto | PTverso |.
The ‘code’ field contains a unique code, different for each specimen. It should be noted that the ‘comments’ field is also very importantsince it can contain information on synonymy, as well as all problems encountered during the process of verification of the type material with the recent catalogues.
Before long the 4374 photographs and the corresponding Excel file will be transferred to a user friendly website. One of the outcomes of this website will be that the section will start a policy of not lending type material any more. Specialists will find low resolution pictures on the web as first information. If better quality is needed, original photographs can be sent by e-mail. If this information is still not satisfactory, the only alternative will be to visit the section and look at the specimens themselves. These photographs and corresponding information should be available on the museum website early next year.
Without the Coolpix 990 brought in by Dr Marc De Meyer through a project, the digitisation would not have been possible.
- Ackery, P.R., Smith, C.R. & Vane-Wright R.I. (eds); 1995. Carcasson's African butterflies: an annotated catalogue of the Papilionoidea and Hesperioidea of the Afrotropical region. East Melbourne: CSIRO, xi + 803 pp.
- Bouyer, T. 1999; Catalogue of African Saturniidae. Entomologia Africana collection hors série n°1, 73 pp, 16 col. pl.
- Fermon, H., Waltert, M., Larsen, T.B., Dall'Asta, U., & Mühlenberg, M. 2000. Effects of forest management on diversity and abundance of fuit-feeding nymphalid butterflies in south-eastern Côte d'Ivoire. Journal of Insect Conservation 4 : 173-189, 4 figs, 6 tabs.
- Goodger, D.T. & Watson, A. 1995. The Afrotropical tiger-moths. An illustrated catalogue, with generic diagnoses and species distribution, of the Afrotropical Arctiinae (Lepidoptera : Arctiidae). Stenstrup, Denmark: Apollo Books, [iv] + 65 pp.
- Kitching, I.J. & Cadiou, J.-M. 2000. Hawkmoths of the world: an annotated checklist of world Sphingidae (Lepidoptera). The Natural History Museum, London: Comstock Publishing Associates, vi +226 pp, 8 col. pl.
- Kiriakoff, S.G. 1960. Lepidoptera, Familia Thyretidae. - in WYTSMAN, P., Genera Insectorum, fasc. 214e. - Imprimerie et Editions Mercurius, 66 pp., 2pl.
- Kiriakoff, S.G. 1964. Lepidoptera, Familia Notodontidae, pars prima, genera Aethiopica et Malgassica. - in WYTSMAN, P., Genera Insectorum, fasc. 217e. - Imprimerie et Editions Mercurius, 213 pp., 11pl.
- Kiriakoff, S.G. 1970. Lepidoptera, Familia Notodontidae, addenda et corrigenda ad partem primam genera Aethiopica et Malgassica. - in WYTSMAN, P., Genera Insectorum, fasc. 217a. - Imprimerie et Editions Mercurius, 74 pp.
- Kiriakoff, S.G. 1970. Lepidoptera, Familia Thaumetopoeidae. - in WYTSMAN, P., Genera Insectorum, fasc. 219e. - Imprimerie et Editions Mercurius, 33 pp., 3pl.
- Kiriakoff, S.G. 1977. Lepidoptera Noctuiformes Agaristidae II (Ethiopian and Madagascan Species) - in Das Tierreich, vol. 98. Walter de Gruyter, Berlin, i-viii + 1-165.
- Larsen, ms. Butterflies of West Africa. Stenstrup, Denmark: Apollo Books,
- Poole, R.W. 1989. Noctuidae. Lepidopterorum Catalogus (New Series) (118), part 1, xii + 1-500, part 2 [iv] + 501-1013, part 3, [viii] +1015-1314. Leiden: E.J. Brill.
- Scoble, M.J., (ed.). 1999. Geometrid Moths of the World: a catalogue. The Natural History Museum, London: CSIRO Publishing, Collingwood, Australia, part 1, xxv + 1-482 + 1-129 (index 1&2), part 2, 485-1016 +1-129 (index 1&2).
- Vane-Wright, R.I. 1997. African Lepidopterology at the millennium. Metamorphoses Supplement 3 : 11-27, 4 figs.
- Watson, A. 1965. A revision of Ethiopian Drepanidae (Lepidoptera). Bulletin of the British Museum (Natural History) (Ent.), Suppl. (3): 177 pp.
- Whalley, P.E.S. 1971. The Thyrididae (Lep.) of Africa and its islands; a taxonomic and zoogeographic study. Bulletin of the British Museum (Natural History) (Ent.), Suppl. (17): 198 pp.