MEANS OF INOCULATION OF THE DUTCH ELM DISEASE BY HYLURGOPINUS RUFIPES EICHH.

Abstract

Investigations on the transmission of the Dutch elm disease were carried out during summer of 1946 in Canada, where the only known vector of the fungus is the native bark beetle, Hylurgopinus rufipes. By close observations of young elms, recently and naturally infected with Ceratostomella Ulmi, it was found that by boring tunnels through the thin bark of twigs or small branches to the cambium, the adults of this beetle can inoculate the disease to healthy trees.