CBT is slowly moving in surges Southward. Eastern movement has yet to be seen due to the barrier of the Cascade Mountain range. Conditions in eastern Washington may not be favorable for CBT to survive. However, eastern orchards may possess the conditions to support CBT populations due to placement in riparian areas and irrigation practices. The following graph illustrates the data collected for each group.
Different letters symbolize a significant difference of preference.
Perhaps some tree defenses have been selected against. Susceptibility CBT infestations are mainly associated with 'mature' trees, but this does not appear to be the case. CBT has been easily found on 3 year old cherries, fruit tree suckers and new plantings of apples. We surveyed 250 oriental flowering cherry trees, P. serrulata , to determine the biological parameters required for CBT infestations. In the field, it is apparent that CBT exploits trees that have multiple opportunities for hatching larvae to gain entrance to the bark.