Neuroterus decipiens

Quercus douglasii, dumosa, garryana, lobata
Leaf galls, integral
Fig 138. Cluster of separate cells in leaf.

Fig 138. On Q. dumosa • Occurs on Q lobata, douglasii and garryana also. Adults emerged Mar 31 (Santa Catalina Id.), April 15 (Paso Robles). May 13 (Santa Rosa).

Neuroterus decipiens, new species

GALLS (P1. XXIV; Fig. 9).-Clusters of egg-like cells in the leaf-blade. Each cell monothalamous, oval, about 1.7 mm. long by 1.0 mm. wide, thin-walled, entirely hollow, equally protruding from either surface of the leaf; leaf-green, drying brownish yellow. In dense, compacted clusters containing many scores of cells; on young leaves of Quercus Douglasii.

RANGE.-California: Stanford University (I. C. McCracken, Coll.), Three Rivers, and Redding.

This species is very abundant early in the spring; the galls are very succulent and the insects mature quickly after the unfolding of the leaves. There must be, therefore, another generation in the year, probably agamic. Insects were emerging at Three Rivers on March 22, but some hundred miles farther north, at Redding, adults did not emerge until some time after collection of the galls on April.2. Of 93 adults of my collection, only 14 are males, not the usual ratio for bisexual generations of this genus. Material of this species is in several collections labelled Neuroterus pacificus Beutenmuller, but this is obviously not that species.

Neuroterus saltatorius (bisexual generation)

These integral leaf galls measure 2 mm long by 1 mm wide and are green when fresh, turning brown with age. This bisexual generation was previously described as a separate species, N. decipiens.

Neuroterus saltatorius (bisexual generation) / Neuroterus decipiens

A leaf blade swelling involving both surfaces of the leaf; each larval cell apparent on the surface as a distinct, egg-shaped cell, the walls thin and without any other cell lining, each cell about 1.7 by 1.0 mm.; clusters up to about 15. mm. in diameter contain up to 60 cells; succulent as the young leaf.

Host:
Quercus douglasii (figs. 49, 50)