TPIE MONTHLY BULLETIN. 351 



to the production of a uniform variety of fruit, and hence the necessity 

 of outlining and studying the main kinds of soil in the great interior 

 valley, separately and individually, so that wherever the soil is the 

 limiting factor of fruit culture, it will be possible to learn its pos- 

 sibilities and avoid many of the mistakes of the past. 



Not only must Ave know the performance duty of the trees from 

 which we obtain our stock for grafting, but it must be known for each 

 of the main bodies of soil on which any variety may be expected to 

 be grown and also for the different root stocks used. 



The future greatness of the great interior valley lies before it. We 

 have scarcely begun to realize that its wide range of soils and favorable 

 climate permit of the growing of almost every kind of fruit that might 

 be desired, but in order to obtain the fullest possible returns, the most 

 comprehensive system of agriculture available is absolutely necessary 

 and every environmental condition required for the fullest returns 

 from the land must be known. The varieties of plants and se(*ds groAvn 

 will l)e in strict harmony with soil types and climate, and that continual 

 round of readjustment which is now causing the loss of thousands of 

 dollars yearly to the farmers of the State will be eliminated. 



THE GREAT BASIN TENT CATERPILLAR IN CALIFORNIA. 



{Malacosoma fragiUs Stretch.) 



Order — Lepidoptera. Family — ^Lasiocampidae. 



By Edwin C. Van Dyke, Department of Entomology, University of California, 



Berkeley, California 



Of the nine species and varieties of the genus Malacosoiiia or tent 

 caterpillars Avhich are listed from North America, seven are to be found 

 on the Pacific coast and five in this State. Our commonest species is 

 Malacosoma californica Pack., a hairy, orange colored caterpillar, some- 

 what over an inch in length, which feeds normally on the live oaks of 

 middle California and occasionally does considerable damag:e to apple 

 trees. M. constricta Stretch, a somewhat larger species having a bluish 

 appearance, because of certain blue lines along its sides, is to be found 

 on our black and white oaks where it sometimes does a great deal of 

 injury. M. pluvialis Dyer, a buff colored species of the country west 

 of the Cascades, is the destructive species of the north. It is very 

 injurious to apple trees, often completely defoliating them, and it 

 congregates in such numbers on the alder, its native food tree, that 

 it becomes a decided nuisance, and as a consequence has resulted in 

 certain park authorities taking steps to have all alders removed. A 

 fourth species, M. fragilis Stretch, closely related to the above and 

 similar in appearance, has also and recently entered the lists as a 

 destructive and annoying species. 



This last mentioned species normally ranges throughout the northern 

 portion of the Great Basin, extending from the Eocky IMountains to 

 the Cascades and Sierra Nevadas, and, according to Dr. Dyer, feeds 

 on the wild gooseberry and wild rose. During the past summer, the 

 caterpillars were to be found in enormous numbers in the territory 

 about Mt. Shasta. The extensive brush areas which are to be found 

 on the southern and eastern slopes and to the northeast of the moun- 



