52 
Psyche 
[March 
2(1). Epipharynx with epizygum (sclerotized strip or patch near 
apex) 3 
2'. Epipharynx without epizygum ...4 
3(2). Plegmata (fig. 7) short, not approaching outer chaetoparia ; 
maxillary stridulatory teeth pointed ....A jnphimallon Berthold 
3'. Plegmata long, closely approaching outer chaetoparia; maxil- 
lary stridulatory teeth truncate 
(in part) Phyllophaga Harris 
4(2')- Dexiophoba (fig. 7) ringing much of right side of pedium; 
maxilla (fig. 4a) with a row of 14 or more long, conical 
stridulatory teeth; haptomerum (fig. 7) with a group of 15 
or more heli Polyphylla Harris 
4'. Dexiophoba short; maxilla with a row of 12-13 short, conical 
arcuate stridulatory teeth; haptomerum with a group of 14 
heli (proximal ones small, setae-like) T'hyce LeConte 
Genus Thyce LeConte, Third Instar Larva 
The larvae of this genus are extremely similar to those of Po/y- 
phylla Harris. This similarity may indicate the monophyly of the 
two taxa which are retained as good genera on the basis of the adult 
antennal characteristics. 
The following combination of characteristics is diagnostic of the 
larvae of the genus Thyce: Head without eye spots. Frons and gena 
with numerous scattered setae, lateral ones long. Labrum symmet- 
rical. Epipharynx with epizygum ; zygum indistinct. Haptomerum 
with a group of 14 heli. Plegmatia present, plegmata short. Propleg- 
matia absent. Dexiophoba short. Haptolachus with microsensilla. 
Maxilla with a row of 12-13 short, conical, arcuate stridulatory teeth. 
Lacinia with longitudinal row of 3 stout unci. Anal slit transverse, 
ventral anal lobe not cleft. Raster with 2 short, longitudinal, parallel 
palidia. Preseptular hamate setae numerous, lateral setae long. 
Claws of prothoracic and mesothoracic legs long and falcate, those 
of mesothoracic legs slightly smaller. Claws of hind legs minute. 
Thyce harfordi Casey, Third Instar Larva 
(Figs, 1-7) 
Material. Eleven specimens of third instar larvae found in pupal 
chambers and burrows beneath cherry trees, 2555 Meridian Avenue, 
San Jose, California, May, 1965; collected by Charles Baker, Toby 
Schuh, J. Gordon Edwards and me. Two specimens taken by Baker 
to Oregon, both subsequently reared by P. O. Ritcher to the adult 
stage. Both were females of Thyce harfordi. 
