Loxaulus trizonalis Weld, agamic.

Quercus chrysolepis
Acorn galls
Fig 186. Separate cells inside acorn.

Fig 186. Cells in large acorns in exposed situations on Q; chrysolepis, no visible deformation. Larvae full-grown Sept. 21, 1922. Adults emerged Mar. 12 and 21, 1925, one was cut out Jan. 21, 1926, more emerged Mar. 16, 1927 (Idyllwild).

Loxaulus trizonalis
agamic

Host. — Quercus chrysolepis.

Gall. — A mass of easily separated contiguous single cells lying on one side of a nature acorn between the cotyledons and the acorn wall. There is no visible external sign of infection, but very large acorns in exposed situations on the tree seemed more liable to attack. The individual galls are irregular in shape, slightly flattened, blunt- pointed at the ends, 4-5 mm. long with exit hole 0.12 mm. in diameter.

Biology. — There is no experimental proof that this is the alternating generation, but the circumstantial evidence is strong. It would be strange to find two series of adults with such unusually marked wings emerging at different seasons from two strikingly different galls on this host oak, which has almost a unique cynipid fauna, unless they were so related. The longer ovipositor of the sexual female seems adapted for piercing acorns and the shorter one of the agamic female for laying eggs in small twigs. Because the author considers these as one species no specific name is given to the agamic form or type designated. The gall on the pin, the locality label, and the field-note number 1577 will serve to identify the agamic series before the author.

Habitat. — The affected acorns were collected at Idyllwild, Calif., on September 21, 1922, and the adults emerged at Washington, D. C, March 12-21, 1925. Others will emerge in spring of 1926.

Loxaulus trizonalis Weld

Distribution.--CA

Biology.--Alternate unisexual and bisexual generations are known. The unisexual generation induces acorn galls while the bisexual generation stimulates stem galls on Quercus chrysolepis. The adults of the bisexual generation emerge from the stem galls in April and oviposit into young acorns; galls of the unisexual generation mature in September and the adults emerge the subsequent spring in March or remain in the galls for one year more and emerge in spring of the second year.