Phylloxera caryaeren Riley

Galls develop in clusters along leaf petioles and mid-ribs of leaflets of Carya glabra; they are reniform, pale green, 2-15 mm max. diam., placed transversely to axis of petiole, deeply divided by a transverse slit and opening into two halves (rather like a bivalve mollusc) when mature (Pergande 1904). The phylloxerid itself is still undescribed, and the life cycle is unknown. In Illinois and Missouri, USA.

Phylloxera caryaeren

Carya sp.
Leaf folds and ridges
Reniform, petiole or midrib gall, a transverse slit dividing the gall into two halves, diameter 2 to 15 mm.

Phylloxera caryaeren

Carya sp.
Petiole or twig galls
Reniform, petiole or midrib gall, a transverse slit dividing the gall into two halves, diameter 2 to 15 mm.

Phylloxera Caryae-ren Riley.

Since the description of this gall nothing new has been added regarding its earlier stages and development ; nor have I had the opportunity of studying its architects.

The galls usually grow, like those of the preceding species, in clusters, though occasionally singly, upon the main petiole, the leaf -stems or the midrib of the leaves of Hicoria glabra, usually along the underside. Frequently, however, they are so closely crowded together as to completely encircle the petioles, never becoming confluent, however. They are always placed transversely with the axis of the petiole, more or less distinctly reniform and divided along their entire transverse length in two equal halves or lids, the edges of which are incurved and pressed closely together while young, but spread open for some distance when mature to allow the insects to escape. The size varies from 2-15 mm and the outer surface is densely pubescent and of a pale green color, with the interior smooth and yellowish-brown. The walls are rather thick and hard and similar in composition to the husks of the nuts.

Phylloxera caryaeren

Kidney-shaped and hard, light green, and densely pubescent; diameter 2.0–15.0 mm; occurs on petioles, stems, and along underside of midvein of leaves; usually occurs in clusters; opening a transverse slit that spreads apart as the gall matures dividing the gall into two equal halves.