Phylloxera glabra (von Heyden)

Living without host alternation mainly on Quercus robur. Fundatrices feed in spring from main veins, sometimes causing inward curling of leaf-edge as in Ph. confusa. Subsequent generations include yellowish orange apterae (BL 0.7-0.85 mm), which lay circular clusters of eggs on the underside of the leaf, and both apterous and (later) alate sexuparae (Grassi 1912). Feeding causes necrotic spots on leaves. In Europe (England, France, Germany, Italy), and introduced to New Zealand, where it is recorded from Q. dentata (Sunde 1984). A record from Turkey (Şenol et al. 2014c) requires additional confirmation. Anholocyclic overwintering may occur; Lubiarz (2007) observed overwintering of immature stages of P. glabra (and/or P. coccinea) in bark crevices in Poland.

Phylloxera glabra

Hosts: Quercus garryana, lobata

Free-living

Range: OR, CA