Data Paper |
Corresponding author: Andree Cappellari ( andree.cappellari@studenti.unipd.it ) Academic editor: Michael Ohl
© 2018 Andree Cappellari, Maurizio Mei, Massimo Lopresti, Pierfilippo Cerretti.
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:
Cappellari A, Mei M, Lopresti M, Cerretti P (2018) BumbleKey: an interactive key for the identification of bumblebees (Hymenoptera, Apidae) of Italy and Corsica. ZooKeys 784: 127-138. https://doi.org/10.3897/zookeys.784.25765
|
BumbleKey is a matrix-based, interactive key to all 45 species of bumblebees of Italy and Corsica. The key allows to identify adult males and females (queens and workers) using morphological characters. The key is published online, open-access, at http://www.interactive-keys.eu/bumblekey/default.aspx.
Bombus , bumblebee, identification tool, interactive key, Italy
The genus Bombus Latreille, 1802 includes around 260 species of eusocial bees, mostly distributed in temperate and cold regions of the northern hemisphere (
In the last decades, an apparent population decline of many species worldwide has been observed (
Bumblebees are pollinators of great ecological and commercial importance throughout much of the temperate world; the industry of greenhouse crop pollination is worth billions of dollars each year (
In Italy ecological studies focused on the effects of climate change and anthropogenic pressure on bumblebee communities, on their role as pollinators, or on the ecology of bumblebees in general, are very few. This is due, at least in part, to the difficulty in identifying these insects to species level by non-specialists. Moreover, the actual occurrence and the detailed distribution of bumblebee species in Italy are poorly known. In this respect, information is based on scattered, occasional, and often old or unreliable data that needs to be updated.
Surprisingly, however, bumblebees are difficult to identify to species level even for experienced taxonomists. They show great intraspecific variability in colouration pattern and a remarkable regional interspecific colouration pattern convergence, which is usually explained in terms of Müllerian mimicry (
Available keys, all dichotomic, for the identification of West-Palaearctic bumblebees are hardly accessible for non-specialists, often lacking of adequate iconography supporting character states assessment (
The study area includes Italy (political boundaries) and Corsica. For practical reasons, the area has been divided into four regions: Alps, Apennine mountains, Italian islands (Sicily and minor islands), Tuscan Archipelago, Sardinia and Corsica (Fig.
The key includes all the 45 species of bumblebees that have been recorded for the study area (
Bombus alpinus (Linnaeus, 1758); B. argillaceus (Scopoli, 1763); B. barbutellus (Kirby, 1802); B. bohemicus Seidl, 1837; B. brodmannicus Vogt, 1909; B. campestris (Panzer, 1802); B. confusus Schenck, 1859; B. cryptarum (Fabricius, 1775); B. distinguendus Morawitz, 1869; B. flavidus Eversmann, 1852; B. gerstaeckeri Morawitz, 1882; B. hortorum (Linnaeus, 1761); B. humilis Illiger, 1806; B. hypnorum (Linnaeus, 1758); B. inexspectatus (Tkalcu, 1758); B. jonellus (Kirby, 1802); B. konradini Reinig, 1965; B. lapidarius (Linnaeus, 1758); B. lucorum (Linnaeus, 1761); B. magnus Vogt, 1911; B. mendax Gerstaecker, 1869; B. mesomelas Gerstaecker, 1869; B. monticola Smith, 1849; B. mucidus Gerstaecker, 1869; B. muscorum (Linnaeus, 1758); B. norvegicus (Sparre-Schneider, 1918); B. pascuorum (Scopoli, 1763); B. pomorum (Panzer, 1805); B. pratorum (Linnaeus, 1761); B. pyrenaeus (Pérez, 1879); B. quadricolor (Lepeletier, 1832); B. renardi Radoszkowski, 1884; B. ruderarius (Muller, 1776); B. ruderatus (Fabricius, 1775); B. rupestris (Fabricius, 1793); B. sichelii Radoszkowski, 1859; B. soroeensis (Fabricius, 1776); B. subterraneus (Linnaeus, 1758); B. sylvarum (Linnaeus, 1761); B. sylvestris (Lepeletier, 1832); B. terrestris (Linnaeus, 1758); B. vestalis (Geoffroy in Fourcroy, 1758); B. veteranus (Fabricius, 1793); B. wurflenii Radoszkowski, 1859; B. xanthopus Kriechbaumer, 1870
The key is designed to allow species-level identification of adult bumblebee specimens, both males and females. The sex of the specimen must be assessed as a first step, as explained in the Instructions section of the key. Specimens should be pinned, and the male genitalia capsule must be pulled out from the metasoma. No dissection or further special preparation are required. All the characters can be examined by means of a stereomicroscope, with incident light and at convenient magnification. Some of the most obvious colour pattern traits can be even assessed to the naked eye.
Thanks to the non-hierarchic structure of the key, the identification of damaged specimens, or part of them, is to some extent possible.
Among the characters traditionally employed in the relevant literature as diagnostic, the ones that are too difficult to observe or to evaluate, as well as those whose evaluation is too subjective or time consuming (e. g. complex measurements) have been excluded. All the characters and states have been verified and evaluated on a reference collection of specimens of all the 45 species included in the key. The reference specimens consist of males, queens, and workers of each species collected on purpose by the authors or preserved in the following collections: Museo di Zoologia, Sapienza Università di Roma, Rome, Italy (
A total of 50 diagnostic characters have been selected, 10 relevant to both males and females, 25 relevant only to females, and 15 relevant only to males. 19 characters are binary, and 31 are multistate with 3-9 alternative states each, for a grand total of 185 states. No character is dependent on the state of another; therefore, their applicability is not constrained, the only limitation being the sex of the specimen to identify.
In many instances, especially in the colouration pattern section, more than one state has been assigned to a character for a given species, to cover most of the intraspecific variability or to avoid possible subjectivity in the assessment of certain character states.
For cryptic species, i. e. those in the so-called “Bombus lucorum-complex” (
PATTERN: face and clypeus hair colour; upperside of the head (vertex) hair colour; bands on mesosoma; mesopleurae main colour; wing colour; hind tibia cuticle colour; hind tibia hair colour; bands on metasoma; metasomal tergites 4-7main colour; metasomal tergites 4-7colour arrangement.
HEAD: [F] antenna, antennomeres A3-A5; [F] antenna – antennal segment A3 ratio; [M] antenna – median antennomeres (A5-A9); [M] eye; [F] ocello-ocular area, sculpture; [F] ocello-ocular area, unpunctured and shining areas; [F] oculo-malar area; [M] oculo-malar area; [F] clypeus, shape; [F] labrum, overall shape; [F] labrum, median furrow and lateral tubercles (overall shape); [F] labrum, median furrow; [F] labrum, lamella shape; [F] labrum, lamella dimension; [F] mandible, number of teeth; [F] mandible, shape; [F] mandible, anterior keel; [F] mandible, sulcus obliquus (posterior groove); [F] mandible, incisura (distal notch); [M] mandible, “beard”.
MESOSOMA: [F] mid basitarsus, distal posterior corner; [F] mid basitarsus, erect hairs on the outer surface; [F] hind tibia, outer surface; [M] hind tibia, outer surface; [F] hind tibia, corbicula; [M] hind tibia, posterior fringe hairs; [F] hind basitarsus, proximal posteriorly-directed process; [F] hind basitarsus: length of posterior fringe’s hairs.
METASOMA: [F] metasomal tergite 6 (T6); [F] metasomal sternite 2(S2); [F] metasomal sternite 6(S6), keels; [M] volsella and gonostylus; [M] volsella, dorsal view; [M] volsella, overall shape; [M] volsella, process of the inner margin; [M] gonostylus, dorsal view; [M] gonostylus, inner process; [M] penis valve, head, dorsal view; [M] penis valve, shaft; [M] gonocoxa, apex, dorsal view.
Every character state is illustrated by 1 to 4 pictures (214 in total). For each species, a minimum of 5 pictures (dorsal female and male habitus, frontal view of female and male head, and male genitalia) have been provided in the species window. For most species, however, multiple pictures (up to 16) are available, in order to illustrate the range of colour-pattern intraspecific diversity or important diagnostic morphological details. The morphological terminology used in the key is illustrated by original line drawings.
Platform: Framework.Net
Web Server: Microsoft Internet Information Service 6.0
Programming language: C#
Application version: MOSCHweb 1.0
Data base: Microsoft SQL Server
Data: 1.0beta
Language: English
License for use of the key: Creative Commons Attribution License 3.0 (CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Use of the primary data: Primary data are available from the authors by agreement.
Web Location: http://www.interactive-keys.eu
BumbleKey interface is simple and intuitive (Fig.
1 – Instructions: a button that refers to a dedicated window, where the user can find information about how to use the key.
2 – Morphology: a button that refers to a dedicated window (Fig.
3 – Bibliography: a button that refers to a dedicated window, illustrating a selection of papers used for the creation of the key.
4 – to cite: a button that refers to a dedicated window, illustrating how user should cite the key.
5 – Species window: an updating real-time box showing all the species that share selected character states. The name of the species is followed by the author name and the year of description. Clicking on a species name, a new window opens to show more information about that species (Fig.
6 – Regions: a button that refers to a dedicated window, showing a map of the four regions in which the study area is divided.
7 – Regions menu: the user can select the region of origin of the specimen to reduce the query to the taxa belonging to that region. By default, all the regions are selected.
8 – Body parts bar: a bar with buttons that allow the user to quickly reach the desired section. Characters are arranged in four sections: pattern (10 characters), head (20 characters), mesosoma (8 characters), and metasoma (12 characters).
9 – Refresh: a button that clears the checkboxes for characters and regions.
10 – Character window: a window with all the characters used in the key and pictures of all the states. Each state picture can be opened in a dedicated window, for example to be compared with other pictures, by clicking on its name in the double temporary view section. The characters can be used in any order, and the more selective ones are highlighted in green. BumbleKey allows for uncertainty to be expressed by the selection of more than one state for each character.
11 – Selected choice box: an updating real-time box showing the chosen characters and state selected by the user, ordered as they appear in the Character window. This represents an ID-code which is linked to the specimen under examination
12 – Export data: a button allowing the user to export in TXT format the terminal taxon/taxa, followed by the list of selected states in the form of a code, together with the specification of the used BumbleKey version. This code serves as a record of the character states used to achieve a specimen identification.
MOSCHweb is an open-access web application, but it is not open source. The application can be modified or updated only by, or in agreement with, the authors of this paper. The authors will keep updated both the web application and the data matrix, by improving encoded descriptions of terminal taxa or by adding possible new taxa to the matrix. Indeed, one of the future desirable developments of BumbleKey will be to better document the chromatic and morphological variation of every species and to extend the key to include all the European and possibly West-Palaearctic species. This would be very difficult with a traditional, dichotomous tool, but with MOSCHweb the problem would be easily solved by augmenting the database with the addition of new data strings to the matrix.
The taxonomy and systematics of Italian and European bumblebees are thoroughly studied and relatively stable (
We thank Bruno Cignini (Museo Civico di Zoologia, Roma) for lending specimens from the Biegeleben collection. We also thank Maurizio Cornalba, Francesco Intoppa, and all the entomologists and non-entomologists who have kindly tested the key.