AbstractsBiology & Animal Science

The growing importance of virus diseases affecting sweet and sour varieties of cherry is gradually bringing about a shift in emphasis on the possible significance of the insect populations of cherry orchards. Hitherto only those species of insects numerous enough to impair the health or efficiency of the trees and their products have been considered of sufficient economic importance to be worthy of extensive study. Now, insects capable of being vectors of virus diseases may assume a significance quite out of proportion to their relative density of population. It was therefore decided to commence a study from this point of view of the insects inhabiting the cherry orchards of the Niagara District of Ontario. The leaf hoppers were chosen as the first group to be investigated as it is in this family that vectors of many other important plant virus diseases are found. [...]