Photo 35: Different  vectors of Dutch elm disease:

A) H. rufipes (Courtesy of I. L. Pines, Manitoba Natural Resources,Winnipeg,  Manitoba, Canada)

B) S. scolytus,

C) S. multistriatus(Courtesy of P. Svihra, University of California, Novato, CA, USA)

In Europe the two principal vectors of DED are Scolytus scolytus and S. multistriatus, the larger and the smaller elm bark beetle respectively (Photo 35B and C). S. laevis, the intermediate-sized European elm bark beetle, is one of the main vectors in Scandinavia and Britain (probably the only one in Norway{[159],[394],[431]}).
The small elm bark beetle S. pygmaeus may also be involved in DED dispersal to some extent in central and southern Europe {[27],[ 371],[ 345]}. Around 1910 S. multistriatus was introduced in North America {[406]}. It has replaced the native elm bark beetle Hylurgopinus rufipes in many parts of the country. However, in contrast to S. multistriatus, H. rufipes is able to survive the cold prairie winter. As a result, H. rufipes  is important for DED transmission in the far northern parts of the United States and Canada (Photo 35A, {[5],[ 235]}). Although S. scolytus  was also introduced in North America in the twentieth century, it never became established {[345],[352]}.