70 ’ DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
larvee enter the bark of trees in the open field, but 1t was commonly 
observed in a laboratory experiment in which apricot branches were 
planted in pots of soil. The branches were about one-half inch in 
diameter and cut in lengths of about 12 inches, and were planted in 
pots or moist sandy soil. The upper cut ends of the branches were 
waxed over, while the lower untreated ends were embedded about 4 
inches in the sand. Clusters of eggs were placed on the branches 
several inches above the soil, just as they would normally be found 
in the field. The larvee, which were very active, immediately sought 
suitable places to begin their burrows, which were sometimes started 
WSS 4 
US 
~ 
Fic. 22.—The California peach borer (Sanninoidea opalescens): a, Larva; b, cocoon and pupal skin; 
c, pupa; c’,abdominal segments of same; c’’, caudal end of same; d, adult female; e, adult male. Much 
enlarged. (Original.) 
even under the eggshells; at other times, at a considerable distance 
from them. Enough of their burrows were made and enough frass 
ejected within a couple of hours to completely cover their bodies. 
Always on the second day they would be found well under the bark 
and to have conspicuous piles of frass above them. They entered 
any small cracks or irregularities of the bark or where the bark 
had been injured and where leaves or small twigs had been cut off. 
They seldom attempted to enter on a clean surface above the ground. 
Most of the larvee penetrated the surface of the soil and entered at 
the lower cut ends. Entering below the surface of the ground is a 
