The striped ambrosia beetles and are timber forest pests in the Palearctic region and North America. Because only a few pathogens are known for species, the aim of this work was to determine the spectrum of pathogen species of , , and . species were collected in pheromone traps at nine localities in the Czech Republic, five localities in Poland, and one locality in Austria. In total, 2,439 , 171 , and 17 beetles were dissected and examined. Infection was found in only two of the 17 specimens of and in only two of the 171 specimens of ; in all four cases, the parasites were nematodes. Parasitisation of by nematodes was found in at eight localities with a mean ( SE) parasitisation level of 8.1 ± 4.7%. A sp. was detected in cells of the midgut epithelium of one specimen, and sp. was detected in the midgut lumen of two specimens; no other pathogens were found in . The low infection rates and the tendency for infection by nematodes can be explained by the monogamy of spp. and their feeding on fungi in short galleries that are not connected to the galleries of conspecifics.