Fungal infection in roots are more severe in the presence of phylloxera. This pest illustrates one of the classic cases of host plant resistance. Native American grape rootstocks are resistant to the grape phylloxera, while European varieties are susceptible. When the insect was introduced into Europe in about 1860, the French wine industry was nearly destroyed. However, the vines were saved by grafting them onto imported American rootstocks.
Resistant rootstocks are still important in preventing damage by the grape phylloxera.
Nymphal establishment and adult reproductive rates are lower on resistant rootstocks than on susceptible types. In the early 1980's, a biotype appeared in California with the ability to colonize some resistant rootstocks. Research in that state has been performed on remote sensing of phylloxera infestations. See additional phylloxera comments , and sampling vineyards from California , and Oregon photo .