Disholcaspis terrestris (agamic)

Disholcaspis edura (agamic)

Disholcaspis spissa (agamic)

Disholcaspis mamillana (sexgen)

Disholcaspis prehensa (sexgen)

Disholcaspis erugomamma (agamic)

D. terrestris Weld can also be found on Q alba.

Disholcaspis edura

[Photos of this gall appear on page 10 of the pdf]



Disholcaspis spissa

[Photos of this gall appear on page 10 of the pdf]


Disholcaspis mamillana Weld, 1957, sexual generation

[A photo of this gall appears on page 13 of the pdf]

Gall (Fig. 20): Length 2.4–2.9mm, buff-colored, oblong grain-shaped, bluntly pointed, thin walled, and glabrous. Arising from the buds at the base of new leaves during spring flush. Emergence holes are rough edged and near the apex. 

Host plant remarks: The recorded host for the asexual generation wasps is Q. douglasii (Weld 1957). All sexual generation specimens here identified as D. mamillana were taken from a field identified Q. douglasii. No host voucher is available for these specimens

Disholcaspis prehensa Weld, 1957, sexual generation

[A photo of this gall appears on page 17 of the pdf]

Gall (Fig. 35): Length 2.2–3.5mm, buff to light brown colored, oblong grain-shaped, bluntly or sharply pointed, thin walled, and glabrous. Arising from the buds at the base of new leaves and flowers when they flush in the spring. Emergence holes are rough edged and near the apex. 

Host plant remarks: Quercus dumosa is the host plant listed in the original description of D. prehensa (Weld 1957). However, the name Q. dumosa has been applied to almost all species of scrub oak in central and southern California. Asexual generation D. prehensa have also been photo-documented (Gross J. 2007 and 2012) and reared from Q. berberidifolia (listed as host for specimen D_prehensa_Dispre3). The host plant voucher for the sexual generation specimens USNMENT00961761, USNMENT00961924, and USNMENT00961763 is deposited at MARY and identified as Q. berberidifolia. This shows that the sexual generation of D. prehensa is found on the same host species as the asexual generation. 

Disholcaspis erugomamma Cooke-McEwen, sp. nov.

[A photo of this gall is included on page 19 of the pdf]

Gall (Fig. 47): Reddish brown, globular with a short, obtusely pointed nipple apically or few may lack the nipple entirely. Dispersed or more commonly tightly clustered and deforming around each other. Internally with dense, rather hard, corky texture; larval cell not free in galls examined. Gall is most similar to that of D. quercusmamma, but the surface is wrinkled in that species and relatively smooth in D. erugomamma. It is uncertain if the galls are nectar secreting, but the black sooty mold that is typical for mature nectar secreting galls was lacking. The galls were covered in dust when found but it is uncertain if that dust was a trait of the gall itself as opposed to its dusty arid environment near a road.

Biology: Only the asexual generation is known at this time. All wasps reared for this study emerged toward the end of December or early January. 

Etymology: Named for the gall morphology. From Latin, erugo meaning to free of wrinkles (noun in apposition) and mamma as a reference to the mammiform gall shape (Brown 1956). 

Distribution: Known only from the single collecting event in western Texas. Collecting site was revisited in spring 2020 and empty fall galls were present. 

Host plant remarks: The host plant voucher is deposited at MARY and identified as Q. havardii. It has a small range from northwestern Texas to New Mexico and Oklahoma, with disjunct populations in northern Arizona and southern Utah (Nixon, 1997).

Contributions to Disholcaspis Dalla Torre And Kieffer (Hymenoptera: Cynipidae: Cynipini)