Oystershell scale and other scale pests - reservoir host plants

Many orchards are affected by more than one scale insect species. The following shelter and other plants are known to be harbouring large populations of scale (all species combined) in the different regions:

Region Host plant Region Host plant
Waikato Plum, barberry, hawthorn, some willows, poplars, wattles and native plants Nelson Birch, willows, alders and poplars, oaks, flowering cherries, Prunus spp., hawthorn
Gisborne Poplars in particular Canterbury Conifers (Parlatoria scale)
Hawkes Bay Plum, peach blocks, hawthorn, birch, walnuts, elms, some alders, willows and poplars Central Otago Plum and other stonefruit, hawthorn, birches, some alders, willows and poplars