Ongoing research being conducted in the Okanagan Valley on potential vectors of grapevine red blotch virus (GRBV) has helped clarify the treehopper species present in this area.
The three-cornered alfalfa treehopper that is suspected of spreading GRBV in the U.S. has not been found here. Rather, two closely related species of buffalo treehopper have been identified in B.C. vineyards (Spissistilus bisonia and S. Bsalis).
The economic status of the buffalo treehopper would change if it was shown to spread GRBV.
Adult buffalo treehopper are green or brown in colour and about 5-6 mm in length. The first section behind the head (pronotum) is elongated to the sides and extends to the rear of the abdomen so that they look somewhat triangular when viewed from the front.
It has a hump-backed appearance of the American bison, after which it is named, when viewed from the side.
Damage to the lateral shoots of grapes caused by treehoppers can somewhat resemble virus infection or other diseases. In summer, late instar nymphs will produce a series of feeding punctures around leaf petioles or stems, resulting in decreased flow of water and nutrients and eventual reddening of leaves beyond the feeding site. The initial feeding punctures coalesce into a darkened band of sunken tissue encircling the stem or leaf petiole.
Although damage is often restricted to lateral shoots and generally not of economic concern, growth of newly planted vines could be stunted in areas with lots of alfalfa or other suitable host plants.
