THE CALIFORNIA PEACH BORER. 67 



NATIVE FOOD PLANTS. 



Mr. J. G. Grundell, who has been a resident in the mountains 

 above Alma, Santa Clara County, since 1894, has many times 

 collected moths on the wing in the foothills lying above the Santa 

 Clara Valley, and he has furnished the only positive record of the 

 rearing of this species from any native plants. Mr. Grundell was 

 at one time experimenting in his little mountain orchard with 

 cuttings of the western chokecherry (Cerasus demissa) as a native 

 grafting stock for cultivated fruit varieties. This plant suckers 

 readily and these suckers were cut and planted to be used as stocks 

 for grafting. Mr. Grundell, by keeping such cuttings as became 

 naturally infested confined in jars, was able at many times to rear 

 adult moths of the California peach borer. The western choke- 

 cherry is indigenous to the Sierra Nevada Mountains, middle North 

 Coast Range (Napa Mountains), Oakland Hills, Mount Hamilton 

 •Range, and the Santa Cruz Mountains, and it is undoubtedly one of 

 the common native food plants of this insect. 



HISTORY OF FRUIT GROWING IN THE SANTA CLARA VALLEY. 



Mr. Grundell says that he has never collected or found the moths 

 in flight in deep woods, but that they seem rather to seek the open 

 or bushy country. He states also that the insect was most easily 

 collected in the hills immediately at the edge of the Santa Clara Valley, 

 and it was here, in the adjoining valley, that the insect first became 

 injurious. The lower foothills and the upper western areas of the 

 Santa Clara Valley were at one time covered with a dense growth 

 of underbrush, which included especially the western chokecherry. 

 Beginning about the year 1880 this land was gradually cleared and 

 planted to orchards. Thus the cultivated varieties displaced some 

 of the insect's native food plants in its native habitat. It was there- 

 fore natural for the insect to adapt itself to those cultivated plants 

 which were closely related to the native varieties, and to extend its 

 habitat into the open and adjoining country. The soil and climate 

 are here especially well adapted to the growing of deciduous fruits, 

 such as peaches, apricots, cherries, and plums, and the entire valley is 

 now practically one continuous orchard. The insect attacks all of these 

 species quite freely and here finds ideal conditions in which to live. 



LIMITS OF AREAS IN WHICH INJURY OCCURS. 



The writer can not understand why an insect which is so widely 

 distributed throughout the western coast States should be so local 

 in its injury in cultivated orchards. The Santa Clara Valley, the 

 areas on either side of San Francisco Bay in Alameda and San Mateo 

 Counties, and small areas near Watsonville, Santa Clara County, are 



