Neuroterus saltatorius variety saltatorius

GALL. — Quite ellipsoidal, almost half again as long as wide, aciculately roughened, apically with a blunt tip which is slightly hairy; gall rather large; on Quercus lobata (and Q. Douglasii?) (figs. 27, 30, 31).

RANGE. — California: Marysville (Aaron coll.); Stockton (acc. Calif. Acad. Proc.) ; Brentwood, Stanford University (McCracken) ; Diablo (Leach coll.) ; Sacramento (C. T. Dodds) ; Paso Robles, Exeter, Napa. Probably thruout Central California over the range of Q. lobata (and Q. Douglasii?).

The variety occurs most commonly on Quercus lobata; a very similar gall, possibly of the same variety, occurs less often on Q. Douglasii, but I have not secured insects and cannot be sure of the relationships. The records for other hosts, as previously pointed out, apply to other varieties. Riley was wrong in considering the eastern United States material identical. Beutenmuller (1910) made the correction, but he did include a figure of a Connecticut, Quercus alba specimen (plate XI, fig. 9).

It is not clear at what season Aaron collected the type material, but the California Academy had previously seen galls (as Mr. Weld points out to me) which were about mature and dropped to the ground in August. Material in the Stan- ford and University of California collections was collected in August and in September as late as September 24. No one, apparently, has ever secured a male of this species, and I fail to find any males in the material collected in September and sent me from the Stanford collection by Dr. McCracken or in the material sent by Professor Essig and Mr. Dodds of the University of California. This amounts only to negative evidence, and we need further proof that this summer generation is agamic, but it does look as if here might be a case of a species in which no bisexual generation ever does occur. I have further examined fine lots of saltatorius material collected at frequent intervals thru the late fall and winter of two years by Mr. Leach, and these galls do not mature until January or February, the insects emerging late in the winter or early in the spring. This is very evidently the winter generation, agamic as we have observed and as would be expected in Neuroterus. I have not described these two generations as different forms because they are apparently identical (even as to sexuality) except for their seasonal occurrence.

Neuroterus saltatorius (unisexual generation)

Gall: Small, subglobular, 1.25-1.50 mm., pale reddish-brown, with a small nipple at either pole; slightly sculptured.

Naeruterus saltatorius (unisexual generation)

Quercus douglasii, dumosa, garryana, lobata
Leaf galls, detachable
Fig 100. Jumping gall. "Flea seeds"

Fig.100. Q. lobata, douglasii, dumosa, garryana. H. H. Keifer sent galls in July from a douglasii tree that had been almost defoliated by Neuroterus decipiens Kinsey in the spring. Galls sent to Washington on July 26 were still jumping actively on Sept. 27 and on Oct. 6. Adults emerged the next April.

Neuroterus saltatorius (unisexual generation)

This cynipid wasp induces tiny (1 mm in diameter), round, monothalamous, detachable brown galls on the underside of leaves of valley, blue, scrub, and Oregon oak. Late spring unisexual generation galls occur singly, but often in large numbers per leaf.

Hosts:
Quercus lobata
Quercus douglasii
Quercus berberidifolia
Quercus garryana