Invasion of alien species has been shown to cause detrimental effects on 
habitats of native species. Insect pollinators represent such examples; the 
introduction of commercial bumble bee species for crop pollination has resulted 
in competition for an ecological niche with native species, genetic disturbance 
caused by mating with native species, and pathogen spillover to native species. 
The European honey bee, Apis mellifera, was first introduced into Japan for 
apiculture in 1877, and queen bees have been imported from several countries for 
many years. However, its effects on Japanese native honey bee, Apis cerana 
japonica, have never been addressed. We thus conducted the survey of honey bee 
viruses and Acarapis mites using both A. mellifera and A. c. japonica colonies 
to examine their infestation in native and non-native honey bee species in 
Japan. Honey bee viruses, Deformed wing virus (DWV), Black queen cell virus 
(BQCV), Israeli acute paralysis virus (IAPV), and Sacbrood virus (SBV), were 
found in both A. mellifera and A. c. japonica colonies; however, the infection 
frequency of viruses in A. c. japonica was lower than that in A. mellifera 
colonies. Based on the phylogenies of DWV, BQCV, and SBV isolates from A. 
mellifera and A. c. japonica, DWV and BQCV may infect both honey bee species; 
meanwhile, SBV has a clear species barrier. For the first time in Japan, 
tracheal mite (Acarapis woodi) was specifically found in the dead honey bees 
from collapsing A. c. japonica colonies. This paper thus provides further 
evidence that tracheal-mite-infested honey bee colonies can die during cool 
winters with no other disease present. These results demonstrate the infestation 
of native honey bees by parasite and pathogens of non-native honey bees that are 
traded globally.