Phylloxera russellae

Hosts: Carya illinoinensis

Button-like and flattened, about equally convex above and below, and green or yellowish-green with a reticulated pattern; diameter 3.2–7.2 mm; opening below surrounded by white pubescence which splits into 2–5 bracts at maturity.

Range: AL, LA, OK

Phylloxera russellae Stoetzel

Galls on Carya illinoensis in southern USA are circular, flattened, diam. 3.2-7.2 mm, with a reticulate surface pattern. They project from both sides of a leaflet with an opening on the underside marked by white pubescence. Galls mature and break open in May. No alatae are known. There is no host alternation; apterous sexuparae produce sexuales which develop in the gall in May and produce overwintering eggs in galls, on twigs, etc. (Stoetzel 1981). Heavy populations of galls can cause defoliation. Calcote (1985) studied resistance of pecan clones to P. russellae.