Phlloxera are tiny, yellowish insects that suck sap from the underside of leaves, particularly on oak species, producing tiny, irregular brown and yellow spots. Damage is primarily aesthetic and is not serious. Either tolerate this pest or apply insecticidal soap to the Underside of affected leaves before they become severely spotted.

Click for larger image
Gall on hickory (Carya) caused by phylloxeras (Hemiptera)
Click for larger image
Gall on hickory (Carya) caused by phylloxeras (Hemiptera)
Click for larger image
Gall on hickory (Carya) cut open and showing the cause: phylloxeras (Hemiptera)
Click for larger image
Close-up of phylloxeras (Hemiptera) inside a gall on hickory (Carya)
Click for larger image
Close-up of phylloxeras (Hemiptera) inside a gall on hickory (Carya)
Click for larger image
Close-up of phylloxeras (Hemiptera) inside a gall on hickory (Carya)
Click for larger image
Close-up of phylloxeras (Hemiptera) inside a gall on hickory (Carya)
Click for larger image
Phylloxera (Hemiptera) are a tiny insects that sometimes feed on roots but can also cause leaf galls, as on these grape leaves (Vitex)
Click for larger image
Close-up of galls on grape leaves (Vitex) caused by phylloxera (Hemiptera)