Andricus lustrans (agamic)

Zopheroteras hubbardi (agamic)

Philonix fulvicollis (agamic)

Acraspis echini (agamic)

Philonix lanaeglobuli (agamic)

Acraspis prinoides (agamic)

Acraspis quercushirta (agamic)

Zopheroteras compressum (agamic)

Phylloteras nigrum (agamic)

Zopheroteras vaccinii

Acraspis vaccinii
Trigonaspis vaccinii

Gall. In clusters on the midrib on the under side of the leaves of post oak (Quercus minor [stellata]) in autumn. They grow in numbers on the opposite sides of the rib. Monothalamous, somewhat bell-shaped and greenish in color gradually becoming reddish late in the season. They are attenuated at the base into a short petiole, fastened to the rib, and at the opposite end they are truncated, and excavated, making their shape somewhat like that of a huckleberry blossom. Length 3 to 4 mm.

Habitat: New England States south to Florida and Texas

The gall begins to develop in August, but does not reach maturity until late in the fall.

Parateras hubbardi Ashmead

Habitat: MI (Detroit)

Nothing is known regarding the habits of this species.

Philonix nigra (Gillette).

Acraspis niger
Acraspis nigra
Acraspis gillettei

Gall. On the underside of the leaves of white oak (Quercus alba), burr oak (Quercus macrocarpa) and dwarf chestnut oak (Quercus prinoides) in the fall. Monothalamous. Globular and covered with a short, dense pubescence, which give them the appearance of felt. Pale ashen gray brown, but brown if long exposed to the weather. Internally it is a larval cell kept in place by a spongy mass that is loosely fibrous on the inner surface of the gall. The outer shell is thin and hard. Diameter 6 to 11 mm.

Habitat: CT, NY, NJ, PA, OH, IL, MI, IO

The gall is usually quite abundant on the leaves of Quercus prinoides. They become easily detached and may be found on the ground under the trees. The fly emerges the following summer. 

Philonix echini

Acraspis echini Ashmead

Gall. On the leaves of swamp white oak (Quercus platanoides) in autumn. Almost globular, with the surface fintely netted or fissured like a strawberry and covered with short spiny prickles. Yellowish in color. Internally there are from one to four cells, but usually only two cells. Diameter 5 to 7 mm.

Habitat: Florida

The gall somewhat resembles that of Philonix erinacei and Philonix pezomachoides. It is smaller than erinacei and larger than pezomachoides. The surface is coarser than in erinacei and the spines are considerably shorter.

Philonix lanaeglobuli (Ashmead)

Acraspis lanaeglobuli

Gall: On the under side of the leaves of swamp white oak (Quercus platanoides [michauxii?]). Round or globular, slightly attached to the leaf and covered with a fine, dense, grayish pubescence. Internally of a pithy structure, with a large thin shelled kernel in the centre. Diameter 7.5 to 8 mm. 

Habitat: Florida

This species is not known to me; the type is in the US National Museum.

Philonix prinoides

Cynips prinoides
Philonix prinoides
Acraspis prinoides

Gall. On the upper or under side of the leaves of dwarf chestnut oak (Quercus prinoides), usually on the mid rib. In August and September. Monothalamous. Hard and woody. Globular with numerous cone-like projections, each with a long or short bristle. Green or yellowish usually tinged with red. Internally there is a rather large larval chamber. Diameter 6 to 12 mm.

Habitat: NY, NJ, OH 

Philonix hirta

Cynips q. hirta
Cynips hirta
Biorhiza hirta
Biorrhiza hirta
Philonix hirta

Gall. On the veins on the upper and under sides of the leaves of chestnut oak (Quercus prinus [montana]) in September and October. Green or yellowish green. Hard, round, with the outer surface composed of fissures each with a short point. Internally there is a single larval cell. Diameter 4 to 6 mm.

Habitat: MA, CT, NY, NJ, DC, PA, KS, CO(?)

The gall very much resembles that of Philonix pezomachoides but the adult is very different from this species. It is allied to Philonix macrocarpae.

Philonix compressa (Gillette)
 
Acraspis compressus 
Acraspis compressa

Gall. Attached to the underside of the leaves of red oak (Quercus rubra) and scarlet oak (Quercus coccinea) in the fall, about the time the leaves are beginning to turn brown. Subglobular bodies from 2 to 3 mm in diameter. The galls appear like wax, and are either pure white or tinged with red while on the leaves, and when cut into are fleshy and juicy like a potato. They fall to the ground with or a little before the leaves, and each develops a single larva which gets its growth in the fall but does not emerge until the following summer. Only a very thin shell of the gall is left after the fly emerges.

The adult of this species is not known to me and Prof. Gillette's description of it and the gall is here reproduced. I have taken the galls in numbers at Katonah, Westchester County, NY, on the undersides of the leaves of the scarlet oak (Quercus coccinea) but did not succeed in rearing the flies. My specimens were collected in October and November. If I remember rightly, I have also taken the galls in New Jersey and on Long Island NY some years ago. 

Habitat: IA, NY

Biorhiza nigra

Biarhiza nigra
Biorrhiza nigra
Xystoteras nigra

Habitat: NY

This species is unknown in collections and I do not seem to recognize it from the description [of the adult only; no gall]. The type is lost.

The species of Biorhiza, Philonix and allied genera, and their galls