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A
preliminary survey of the bumblebees of the Val Malenco
(Lombardy,
Italy)
(preliminary
version - 24 October 2010)
Maurizio
Cornalba
The following is
an account of observations of bumblebees made in the Val Malenco
between 22 and 28
August 2010. The Val Malenco is a side valley of Valtellina (map),
bounded by two major mountain groups, the Bernina range to the north
and the
Disgrazia-Masino-Bregaglia range to the west, and by lesser mountains
to the east. About midway, the valley divides into two forks, the one
of the river Mallero
to the west, and the one of the river Lanterna to the east. Most of the
localities visited lie in the drainage of the Lanterna. In the
literature, there seem to be very few records of bumblebees for the
valley; the only ones I am aware of are a record of Bombus pascuorum, one of B. soroeensis, one of B. sylvarum [2], and one of B. rupestris [6].
On the other hand, given the high diversity of the valley in elevation
(from a few hundred metres to over 4000 m asl), terrain and vegetation,
it was reasonable to expect that it might host an equally diverse
bumblebee community. This has indeed turned out to be the case.
Altogether, I have observed 23 different species of bumblebees, as detailed in the list below. Of the species found, Bombus alpinus, B. mucidus and B. subterraneus appear to be new for Lombardy.
Altogether, I have observed 23 different species of bumblebees, as detailed in the list below. Of the species found, Bombus alpinus, B. mucidus and B. subterraneus appear to be new for Lombardy.
| Species | number of localities | number of individuals | altitudinal range |
| alpinus (Linné, 1758) | 1 | 1 | 2612 |
| barbutellus (Kirby, 1802) | 1 | 1 | 1501 |
| bohemicus Seidl,1837 | 1 | 1 |
1650 |
| hortorum (Linné, 1761) | 1 | 1 |
943 |
| humilis Illiger, 1806 | 2 |
7 |
943-1501 |
| hypnorum (Linné, 1758) | 1 | 2 |
1915 |
| inexspectatus (Tkalcu, 1963) | 1 | 1 |
1501 |
| lapidarius (Linné, 1758) | 5 | 26 | 943-2612 |
| lucorum (Linné, 1761) | 4 | 6 | 1650-2760 |
| mendax Gerstaecker, 1869 | 2 | 2 |
2690-2760 |
| mesomelas Gerstaecker, 1869 | 4 | 7 | 943-2515 |
| monticola Smith, 1849 | 5 | 8 |
1600-2760 |
| mucidus Gerstaecker, 1869 | 6 |
11 |
2005-2612 |
| pascuorum (Scopoli, 1763) | 3 | 19 | 943-1650 |
| pratorum (Linné, 1761) | 1 | 3 |
1650 |
| pyrenaeus Pérez, 1880 | 7 | 14 | 1980-2760 |
| ruderarius (Müller, 1776) | 1 | 1 | 2410 |
| rupestris (Fabricius, 1793) | 2 | 2 |
943-2612 |
| sichelii Radoszkowski, 1860 | 2 | 4 | 1650-2690 |
| soroeensis (Fabricius, 1777) | 4 | 26 | 1600-1980 |
| subterraneus (Linné, 1758) | 1 |
1 | 2385 |
| sylvestris (Lepeletier, 1832) | 1 | 3 | 1650 |
| wurflenii Radoszkowski, 1860 | 4 |
6 | 2315-2690 |
| Allopsithyrus
sp. Popov, 1931 |
1 | 1 | 943 |
It is virtually certain that this list is incomplete. Other species to be expected are B. terrestris, perhaps B. sylvarum and B. argillaceus, which has been recorded in nearby localities of the Valtellina, and probably other Psithyrus, notably B. campestris, B. quadricolor and B. flavidus. B cryptarum is also a possibility.
Perhaps the most remarkable finding of my exploration of the Val Malenco is the presence of B. alpinus, B. mucidus and B. subterraneus, none of which had been previously reported from Lombardy. On the other hand, all three have been recorded just north of the Bernina range in the upper Engadin, whose bumblebee fauna is in fact almost identical to the one encountered in the higher elevations of the Val Malenco [1]. In particular, B. mucidus has been found to be common in the latter above 2000 m. This is somewhat puzzling in view of the fact that accurate searches carried out, for instance, in the Adamello Alps [4] or in the Orobic Alps [3] have failed to reveal the presence of the species in the alpine portion of Lombardy south of the Valtellina. The other two species have been found as single specimens, B. alpinus at high elevation near the edge of the glaciated core of the Bernina massif, and B. subterraneus in the gently sloping, extensive alpine prairies of the Val Poschiavina. Near the place where the specimen of B. subterraneus, a typical worker of the subspecies latreillellus, was found, I saw a large dark bumblebee which I could not determine but that looked like a queen of the dark form of subterraneus. This form is also present in the Engadin.
B. gerstaeckeri has not been found. One reason might be that, in the localities I visited, Aconitum, on which it specializes, is very scarce and never occurs in large aggregations. On the other hand, the species is known from the Poschiavo valley immediately to the east of the area considered here [1], and hence more exhaustive searches might reveal its presence also in the Val Malenco. By contrast, B. inexspectatus has been found in the valley. This, together with the recent discovery of other localities for the species in Lombardy and Valle d'Aosta, confirms me in my impression that inexspectatus is widely distributed, and not too uncommon, in the Italian Alps.
A final remark concerns the two individuals listed above as B. barbutellus and "Allopsithirus sp.". They are both rather worn queens, quite dark, with relatively short hair and lightly infuscated wings. The first individual shows well-defined, though very narrow, light bands on collar and scutellum, and has long enough hair, particularly in the posterior fringes of the hindlegs, for me to classify it as barbutellus. The second individual appears virtually all dark, except for scattered light hairs on collar and scutellum and small yellowish lateral patches on T4 and T5, and seems to have shorter hair; nevertheless, I am inclined to consider it just a melanic specimen of barbutellus. However, it is too worn for me to risk a precise diagnosis, hence the classification just under the old subgeneric name of Allopsithyrus.
1. Amiet F. 1996. Hymenoptera Apidae, 1. Teil. Allgemeiner Teil, Gattungsschlüssel, die Gattungen Apis, Bombus und Psithyrus. Insecta Helvetica (Fauna) 12: 98 pp.
2. Bolchi Serini G., Marianelli P. 1994. La collezione di Bombus Latr. del Museo Civico di Storia Naturale di Milano. Boll. Zool. Agr. Bachic., Ser II, 26 (1): 1-26.
3. Cornalba M. 2010. Bumblebees of the upper Brembo valley (Lombardy, Italy). Available online at: http://www-dimat.unipv.it/cornalba/bombi/ bombremb/bombremb.html
4. Intoppa F., Moreschi I., Piazza M.G., Bolchi Serini G. 1995. Bombus Latreille e Psithyrus Lepeletier del "Parco Naturale dell'Adamello" (Hymenoptera Apidae Bombinae). Boll. Zool. Agr. Bachic., Ser II, 31 (2): 167-178.
5. Intoppa F., Piazza M.G., Ricciardelli D'Albore G. 1995. Catalogo bibliografico delle specie di Bombidae (Hymenoptera Apoidea) segnalate per l'Italia. Apicoltura 10, supplemento. pp. 135.
6. Magretti P. 1881. Sugli Imenotteri della Lombardia. Memoria I. Boll. Soc. ent. ital. XIII: 3-42; 89-123; 213-273.
Appendix
Specimens, localities and foraging plants
Specimens, localities and foraging plants
| Species | Localities and foraging plants |
| alpinus (Linné, 1758) | Bocchetta
delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010;
1 male; on Cirsium spinosissimum |
| barbutellus (Kirby, 1802) | Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 1 queen; on Trifolium pratense |
| bohemicus Seidl,1837 | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 1
male; on Centaurea sp. |
| hortorum (Linné, 1761) | Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 1 worker; on Trifolium pratense |
| humilis Illiger, 1806 | Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 1 worker, 1 male; on Trifolium pratense, Impatiens glandulifera Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 3 workers, 2 males; on Trifolium pratense |
| hypnorum (Linné, 1758) | trail to Alpe Ventina, Chiesa in Valmalenco (SO); 46.300497 N 9.776544 E; 1915 m; 26.8.2010; 2 workers; on Epilobium angustifolium |
| inexspectatus (Tkalcu, 1963) | Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 1 male; on Centaurea sp. |
| lapidarius (Linné, 1758) | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 3
workers, 2 males; on Centaurea sp. Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 10 workers; on Trifolium pratense, Impatiens glandulifera Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 1 worker; on Centaurea sp. val Poschiavina, Lanzada (SO); 46.299997 N 9.995067 E; 2410 m; 25.8.2010; 5 workers; on Cirsium spinosissimum Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 3 workers; on Cirsium spinosissimum |
| lucorum (Linné, 1761) | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 1
male; on Centaurea sp. Passo di Canciano, Lanzada (SO); 46.297339 N 9.991347 E; 2515 m; 25.8.2010; 3 workers; on Anthillis vulneraria trail to Capanna Marinelli, Lanzada (SO); 46.343914 N 9.907133 E; 2760 m; 28.8.2010; 1 queen; on Cirsium spinosissimum Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 1 worker; on Cirsium spinosissimum |
| mendax Gerstaecker, 1869 | trail to Capanna Marinelli, Lanzada (SO); 46.343914 N 9.907133 E; 2760 m; 28.8.2010; 1 worker; on Cirsium spinosissimum trail to Capanna Marinelli, Lanzada (SO); 46.342750 N 9.907381 E; 2690 m; 28.8.2010; 1 worker; on Cirsium spinosissimum |
| mesomelas Gerstaecker, 1869 | Alpe Palù di Caspoggio, Lanzada (SO); 46.291533 N
9.919958 E; 1650 m; 22.8.2010; 3 workers; on Trifolium sp., Cirsium sp. Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 1 worker; on Trifolium pratense Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 1 worker; on Trifolium pratense Passo di Canciano, Lanzada (SO); 46.297339 N 9.991347 E; 2515 m; 25.8.2010; 2 workers; on Anthillis vulneraria |
| monticola Smith, 1849 | Chiareggio, Chiesa in Valmalenco (SO); 46.317539 N 9.796133 E; 1600 m; 23.8.2010; 1 worker; on Epilobium angustifolium Alpe Ventina, Chiesa in Valmalenco (SO); 46.296267 N 9.778233 E; 1980 m; 23.8.2010; 1 male; on Epilobium angustifolium Passo di Canciano, Lanzada (SO); 46.297339 N 9.991347 E; 2515 m; 25.8.2010; 1 queen, 3 workers; on Trifolium badium, Anthillis vulneraria trail to Capanna Marinelli, Lanzada (SO); 46.343914 N 9.907133 E; 2760 m; 28.8.2010; 1 queen; on Cirsium spinosissimum Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 1 male; on Cirsium spinosissimum |
| mucidus Gerstaecker, 1869 | Alpe
Campagneda, Lanzada (SO); 46.299194 N 9.943075 E; 2156 m, 25.8.2010; 1
worker; on Carduus defloratus Piano di Campagneda, Lanzada (SO); 46.297500 N 9.964339 E; 2315 m; 25.8.2010; 3 workers, 1 male; on Cirsium spinosissimum lago di Alpe Gera, Lanzada (SO); 46.315261 N 9.950342 E; 2140 m; 25.8.2010; 2 workers; on Cirsium spinosissimum lago di Campomoro, Lanzada (SO); 46.310994 N 9.943572 E; 2005 m; 25.8.2010; 1 worker; on Epilobium fleischeri trail to Rifugio Bignami, Lanzada (SO); 46.319394 N 9.941900 E; 2170 m; 27.8.2010; 1 queen, 1 worker; on Carduus defloratus, Lotus corniculatus Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 1 male; on Cirsium spinosissimum |
| pascuorum (Scopoli, 1763) | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 3
workers; on Trifolium sp. Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 10 workers; on Trifolium pratense, Impatiens glandulifera Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; 3 workers; on Trifolium pratense |
| pratorum (Linné, 1761) | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 2
workers, 1 male; on Cirsium palustre |
| pyrenaeus Pérez, 1880 | Alpe
Ventina, Chiesa in Valmalenco (SO); 46.296267 N 9.778233 E; 1980 m;
23.8.2010; 2 workers; on Epilobium angustifolium Piano di Campagneda, Lanzada (SO); 46.297500 N 9.964339 E; 2315 m; 25.8.2010; 1 male; on Cirsium spinosissimum Passo di Campagneda, Lanzada (SO); 46.301850 N 9.984528 E; 2632 m; 25.8.2010; 1 male; on Campanula scheuchzeri Alpe Fellaria, Lanzada (SO); 46.329578 N 9.947992 E; 2410 m; 27.8.2010; 2 males; on Cirsium spinosissimum trail to Capanna Marinelli, Lanzada (SO); 46.343914 N 9.907133 E; 2760 m; 28.8.2010; 2 males; on Cirsium spinosissimum trail to Capanna Marinelli, Lanzada (SO); 46.342750 N 9.907381 E; 2690 m; 28.8.2010; 1 worker, 1 male; on Cirsium spinosissimum Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 2 workers, 2 males; on Cirsium spinosissimum |
| ruderarius (Müller, 1776) | Alpe Fellaria, Lanzada (SO); 46.329578 N 9.947992 E; 2410 m; 27.8.2010; 1 male; on Cirsium spinosissimum |
| rupestris (Fabricius, 1793) | Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 1 queen; on Trifolium pratense Bocchetta delle Forbici, Lanzada (SO); 46.329858 N 9.901619 E; 2612 m; 28.8.2010; 1 male; on Cirsium spinosissimum |
| sichelii Radoszkowski, 1860 | Alpe Palù
di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 3
workers; on Centaurea sp. trail to Capanna Marinelli, Lanzada (SO); 46.342750 N 9.907381 E; 2690 m; 28.8.2010; 1 queen; on Cirsium spinosissimum |
| soroeensis (Fabricius, 1777) | Alpe Palù di Caspoggio, Lanzada (SO); 46.291533 N
9.919958 E; 1650 m; 22.8.2010; ssp. proteus;
1 queen, 10 workers, 10 males; on Centaurea sp. Chiareggio, Chiesa in Valmalenco (SO); 46.317539 N 9.796133 E; 1600 m; 23.8.2010; ssp. proteus; 1 male; on Epilobium angustifolium Alpe Ventina, Chiesa in Valmalenco (SO); 46.296267 N 9.778233 E; 1980 m; 23.8.2010; ssp. proteus; 1 male; on Epilobium angustifolium Franscia, Lanzada (SO); 46.292706 N 9.912006 E; 1501 m; 24.8.2010; ssp. proteus; 2 workers, 1 male; on Centaurea sp. |
| subterraneus (Linné, 1758) | val Poschiavina, Lanzada (SO); 46.304381 N 9.992286 E; 2385 m; 25.8.2010; ssp. latreillellus; 1 worker; on Cirsium spinosissimum |
| sylvestris (Lepeletier, 1832) | Alpe Palù di Caspoggio, Lanzada (SO); 46.291533 N 9.919958 E; 1650 m; 22.8.2010; 2 queens, 1 male; on Centaurea sp., Cirsium palustre |
| wurflenii Radoszkowski, 1860 | Piano di Campagneda, Lanzada (SO); 46.297500 N 9.964339 E; 2315 m; 25.8.2010; 1 worker; on Cirsium spinosissimum Passo di Canciano, Lanzada (SO); 46.297339 N 9.991347 E; 2515 m; 25.8.2010; 3 workers; on Anthillis vulneraria val Poschiavina, Lanzada (SO); 46.299997 N 9.995067 E; 2410 m; 25.8.2010; 1 worker; on Cirsium spinosissimum trail to Capanna Marinelli, Lanzada (SO); 46.342750 N 9.907381 E; 2690 m; 28.8.2010; 1 worker; on Cirsium spinosissimum |
| Allopsithyrus
sp. Popov, 1931 |
Chiesa in Valmalenco (SO); 46.269097 N 9.854375 E; 943 m; 23.8.2010; 1 queen; on Trifolium pratense |
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