Charles W. Johnson.
The North American Varieties of Volucella bombylans Linn.
Psyche 32(2):114-117, 1925.

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114 Psyche [April
THE NORTH AMERICAN VARIETIES OF VOLUCELLA BOMBYLANS LINN.
BY CHARLES W. JOHNSON.
Boston Society of Natural History.
My paper entitled, "The Volucella bombylans Group in America" (Psyche, 1916, vol. 23, p. 159-163), was written primarily to encourage a study of this group and of their relation to the various species of Bombus or Bremus. My system of naming in the above paper might deserve some criticism from a strictly nomenclatorial standpoint. I have therefore in the following table and notes endeavored to correct an error and to make more clear my views on the relationship of these various forms.
Volucella facialis Will. cannot be satisfactorily separated from the var. plumata of Europe, but as the typical bombylans is absent in America, it seems best to recognize facialis as a sub- species. I am also considering the eastern evecta and the Labrador arctica as subspecies, and the other forms as varieties of these subspecies.
The question naturally arises, are these variations worthy of distinct names, especially when European authors have placed twenty-four names (including the American evecta, sanguinea and facialis) in the synonomy under bombylans? Ignoring variation, when it exists in such a widely distributed species, does little to encourage a study of this most interesting syrphid. If certain forms do actually resemble the species of Bombus in whose nests it is commensal, then a knowledge of the possible limits and dis- tribution of these variations is essential for a biological study, Table of subspecies and varieties.
1. Face yellow, with yellow pile. ......................... .2 Face black or dark brown, with yellow pile. .............. .3 2, Dorsum of the thorax and the pleura black pilose, third abdominal segment black pilose (Calif. to Alaska) ......... subsp. facialis Will.




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19251 North American Varieties of Volucella bombylans Linn 115 . Dorsum of thorax black pilose, pleura yellow pilose, third abdominal segment black pilose (N. H. to Newfoundland:. . var. lateralis Johns.
Dorsum of thorax black pilose, pleura yellow pilose, posterior margin of the second and a large dorsal spot on the third abdominal segment red, bearing reddish pile (Col., Utah, N. M.). ....................... var. rufornaculata Jones. 3.
Antennae dark brown, thorax with the pile in front of a line between the base of the wings black in the c? and mixed with yellow in the 9, abdomen entirely yellow pilose (Labrador). ....................... subsp. arctica Johns. Antennae red, pile of the thorax and pleura entirely yellow, first and second and the fourth and fifth segments of the abdomen with yellow or red pile (Eastern U. S.). ...... ... subsp. evecta Walker.
Abdomen with the pile of the first and second segments yellow, the others entirely black. ... var. americana Johns. Abdomen with pile on the first and second yellow, a portion of the third segment reddish pilose, and the remaining .
segments with either red or yellow pile. ................. var. sanguinea Will.
Volucella bombylans facialis var. lateralis Johnson. V. plumata Macq., Dipt. Exot., 4, Suppl. p. 131, 1844. V. bombylans form lateralis Johns., Psyche, vol. 23, p. 161, 1916.
This is the eastern representative of facialis distinguished chiefly by having. the pile of the pleura yellow. The variety is quite common at Mt. Desert and the only form I have taken on the island. It belongs to the Canadian zone. Volucella bombylans facialis var. rutomaculata Jones. V. bombylans form sanguinea Johnson (non Williston), Psyche, vol. 23, p. 162, 1916.
V. rufornaculata Jones, Ann. Ent. Soc. Amer., vol. 10, p. 227, 1917.
This was referred to sanguinea in my previous paper, on the strength of the reddish pile on the abdomen. Since then I have



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116 Psyche [April
received a specimen from Pennsylvania referable to evecta with reddish pile on the third segment, which indicates that Williston probably had eastern specimens before him. Rufomaculata seems to be peculiar to the more elevated portions of the Rocky Moun- tains.
Volucella bombylans arctica Johnson.
V. bombylans from arctica Johns., Psyche, vol. 23, p. 163, 19 16.
With only the American forms for comparison I would have considered this a distinct species, but it resembles so closely specimens in my collection from the Alai Mountains, Turkestan, received under the name V. hcemorrhoidalis Zett., that it seems best to consider it an arctic subspecies of this circumboreal species. Types from Rama and Nain, Labrador. Volucella bombylans evecta Walker.
V. evecta Walker, Ins. Saund. Dipt., p. 251, 1856. Walker's description calls for a form with-head black, an- tennse reddish, thorax thickly clothed with "tawny hairs," abdomen with black hairs, with two bands of "tawny hairs, one band at base paler than the other which is near the tip." Walker does not clearly define the difference between a light yellow and a reddish yellow so that the pile on the posterior segments of evecta may be either yellow or reddish. In actual use the word tawny covers many shades of color from pale ochre to swarthy brown. Evecta is the upper austral form extending through the transition zone.
Volucella bombylans evecta var. americana Johnson. V. bombylans form americana Johns., Psyche, vol. 23, p. 162, 1916.
This is the more common form, the typical evecta being less frequently taken in New England.




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19251 North American Varieties of Volucella bombylans Linn 11 Volucella bombylans evecta var. sanguinea Will. V. evecta var. sanguinea Will., Synop. N. A. Syrphidse, p. 186, 1886.
Specimens of evecta referable to this variety are rare. A
specimen received from Mr. A. B. Champlain, taken at Charter Oak, Pa., July 11, 1917 (H. B. Kirk), has a dorsal patch in the third and the greater portion of the fourth segment with red pile. A specimen from Sherborn, Mass., June 13, 1913 (E. J. Smith), has a large patch of red pile on the third segment while the pile on the fourth and fifth segments is yellow. This variety will have to be restricted to those with red pile on the third seg- ment. It represents-in a way-a parallel variation -to that of rufomaculata in the subspecies facialis, but lacks the red ground color.
The III. International Congress of Entomology will take place at Zurich from July 19th to 26th, 1925. President: Dr. A. von Schult hess-Schindler.
Informal reception on Sunday evening July 19th; distribu- tion of programmes, etc.
Membership 25 Swiss francs, associates accompanying mem- bers $12.50, Life-membership $250.00.
Entomological Societies, Institutions and Departments of Zoology,' Forestry, Agriculture, Horticulture and Hygiene are invited to send Delegates.
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