Distribution of pests on Vitis riparia in sandy soils of the south-western Ontario.
Vitis riparia (Michaux) is native to North America and tolerates the local weather and soil conditions of south-western Ontario in Canada. A survey was done on V. riparia to elicit the distribution of pests on the species in central south-western Ontario. Eight hundred and forty four genotypes of V. riparia were observed throughout the sandy soils of five counties in Ontario (Brant, Elgin, Middlesex, Norfolk and Oxford). The location of the selected vines was labeled in the Geographic Information System (GIS). The ArcGIS program was used to make maps of the distribution of the wild grape pests, Phylloxera, Japanese beetle, Filbert gallmaker, Cane Filbert gallmaker, Tumid Filbert gallmaker and Tube Filbert gallmaker midges in those areas. The results show that the density of pests on V. riparia is more severe in some areas than others. Phylloxera and Japanese beetle were the major pests observed. Phylloxera was most prevalent and Japanese beetle least prevalent in Elgin County. The gallmaker midges were found in low densities throughout the area. The distribution of Phylloxera could be related to the soil type, and the distribution of Japanese beetle and Tumid gall midge to the land use. With Phylloxera, it appears that they prefer poor drainage soils which do not dry out readily. Whereas, Japanese beetle and Tumid gall midge prefer undisturbed soils where they can overwinter successfully.