70 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



larvae enter the bark of trees in the open field, but it 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 larvae, which were very active, immediately sought 

 suitable places to begin their burrows, which were sometimes started 



Fig. 22. — The California peach borer {canninoidea 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 larvae penetrated the surface of the soil and entered at 

 the lower cut ends. Entering below the surface of the ground is a 



