Bombus (Pyrobombus) johanseni Sladen, 1919

Sheffield, Cory S., Oram, Ryan & Heron, Jennifer M., 2020, Bombus (Pyrobombus) johanseni Sladen, 1919, a valid North American bumble bee species, with a new synonymy and comparisons to other " red-banded " bumble bee species in North America (Hymenoptera, Apidae, Bombini), ZooKeys 984, pp. 59-81 : 59

publication ID	https://dx.doi.org/10.3897/zookeys.984.55816
publication LSID	lsid:zoobank.org:pub:12323F95-59D6-41EC-B57F-F6C47318B27D
persistent identifier	https://treatment.plazi.org/id/C76E0117-BA5F-55B7-95EE-C34AD0A3A5DE
treatment provided by	ZooKeys by Pensoft
scientific name	Bombus (Pyrobombus) johanseni Sladen, 1919
status	comb. nov.

Treatment

Bombus (Pyrobombus) johanseni Sladen, 1919 comb. nov.

Bombus sylvicola var. johanseni Sladen, 1919: 30g [♀]. Holoytpe ♀. CANADA, Northwest Territories*, Bernard Harbour, 3 July 1916 [3 July 1915], Canadian Arctic Expedition, by F. Johansen [Canadian National Collection of Insects, Arachnids, and Nematodes, CNC no. 2029]. [photographs of holotype examined, see Fig. 2 View Figure 2 ].

Bombus (Pyrobombus) interacti Martinet, Brasero, & Rasmont, 2019: 611 [♀, ♂]. syn. nov. Holotype ♂. USA, Alaska, Toolik field station, 68°37'32.9"N 149°35'48.8"W, 725m, 28 July 2015, by Martinet and Rasmont, on Epilobium angustifolium [Royal Belgian Institute of Natural Sciences]. Photographs of holotype (as per Martinet et al. 2019) examined.

Diagnosis.

Among the members of the Bombus lapponicus - complex, and other Pyrobombus considered here, B. johanseni is genetically most similar to the northern Palearctic B. glacialis (and see Martinet et al. 2019). In northern North America, the melanistic females of B. johanseni (Figs 2 View Figure 2 , 3 View Figure 3 , 4a, b View Figure 4 ) are most similar to darker forms of B. melanopygus (Fig. 4c View Figure 4 ) and atypical dark forms of B. ternarius Say, 1837 from Newfoundland and Labrador (Fig. 7c, d View Figure 7 ), while paler forms (i.e., " interacti ") are most similar to B. lapponicus sylvicola (Fig. 4d View Figure 4 ); all these taxa have the characteristic “red-banded” metasomal colour pattern of tergum 1 primarily yellow, terga 2 and 3 primarily red or orange, and tergum 4 primarily yellow at least laterally (Fig. 5a View Figure 5 ); with T5 yellow, at least laterally. Bombus johanseni females differ from these other taxa by the colour of the pubescence on the face, being entirely dark in B. johanseni (Figs 2a View Figure 2 , 3a View Figure 3 , 4a, b View Figure 4 , 6a, b View Figure 6 ; but see Martinet et al. 2019), but primarily yellow in B. lapponicus sylvicola (Figs 4d View Figure 4 , 6e View Figure 6 ) or strongly intermixed in B. melanopygus (Figs 4c View Figure 4 , 6c View Figure 6 ). The dark forms of B. johanseni also have extensive dark pubescence on much of the mesosoma, including the pleura (Figs 2 View Figure 2 , 3 View Figure 3 , 4a, b View Figure 4 ), with the dark pubescence extending laterally on the dorsal anterior surface (Figs 2 View Figure 2 , 3a View Figure 3 , 4a View Figure 4 , 6a View Figure 6 ), the latter characteristic shared only with dark specimens of B. melanopygus , though in the latter species the hair is usually intermixed (Figs 4c View Figure 4 , 6c, d View Figure 6 ), not a solid colour (Figs 2 View Figure 2 , 3 View Figure 3 , 4a View Figure 4 , 6a, b View Figure 6 ). Other specimens of B. johanseni have dark hairs on the pleura, with hairs becoming paler on the dorsal surface (Fig. 4b View Figure 4 ), while others (i.e., interacti ) are almost entirely pale haired on the pleura (but becoming somewhat darker below) and dorsal surface (see Martinet et al. 2019) and more closely resemble B. lapponicus sylvicola (Figs 4d View Figure 4 , 6e, f View Figure 6 ). Morphologically, the females of B. johanseni and B. lapponicus sylvicola are very similar ( Martinet et al. 2019), as are the Old World taxa B. glacialis and B. lapponicus lapponicus ( Potapov et al. 2017).

The “red-banded” pattern (Fig. 5a View Figure 5 ) of these northern taxa is also shared with other, typically more southern species, including B. ternarius , B. huntii Greene, 1860, some B. vancouverensis , and some B. rufocinctus Cresson, 1863 (Fig. 7 View Figure 7 , and see Mimicry Pattern 5 in Williams et al. 2014), though these latter species generally tend to have females with either T5 entirely black ( B. huntii , B. ternarius , Fig. 7a, d View Figure 7 ), or with tergum 2 black ( B. vancouverensis , Fig. 7e View Figure 7 ) or yellow ( B. rufocinctus , Fig. 7f View Figure 7 ) basiomedially.

In North America, the males of B. johanseni resemble B. lapponicus sylvicola , B. ternarius , B. huntii , some B. vancouverensis , and pale individuals of B. melanopygus . The males of B. johanseni and B. lapponicus sylvicola can be distinguished from all other Pyrobombus in North America by the bulbous tip of the penis valve ( Stephen 1957; Thorp et al. 1983; Williams et al. 2014) (Fig. 8 View Figure 8 ), though in the former, the tip of the penis valve (Fig. 8a View Figure 8 ) is not quite as bulbous as in B. lapponicus sylvicola (Fig. 8b View Figure 8 ). In B. johanseni , sternum 7 has more elongate hairs on the apicolateral edges, with a shallower apicomedial depression somewhat rectangular, approximately 1/4 as deep as wide (Fig. 9a View Figure 9 ), but broadly U-shaped in B. lapponicus sylvicola , and 1/3 as deep as wide (Fig. 9b View Figure 9 ).