Olliffiella cristicola

Hosts: Quercus emoryi, seldom Q hypoleucoides [observation on Q undulata listed as "questionable"]

The galls, located on the undersurface of the leaf, are 10-12 mm long, 6-8 mm wide at base, compressed laterally to 5-9 mm, and taper into a sharp point. The gall opening is an elongate slit parallel to the midrib on the upper surface of the leaf. Two to four galls may be on a single leaf; occasionally two galls are fused. Dry galls are hard and woody. The female fills the lower or pointed end of the cavity of the gall and lies with its dorsum toward the opening. The overall shape of the female is conical, conforming to the shape of the cavity with a heavily sclerotized, flat, circular dorsum and a membranous or slightly sclerotized venter. It remains questionable how the first instars escape from under the female and through the opening of the gall.

Remarks. This species is found on Quercus "wrightii," and Q. emoryi in New Mexico, Arizona and Mexico. It is the only North American Kermesidae to form a gall.

- Stephen Bullington, Michael Kosztarab: (1985) Studies on the morphology and systematics of scale insects. No. 12^©