268 RESOURCES OF CALIFORNIA. 



The gopher may be poisoned with phosphorus or strychnine, 

 and may be caught more readily with traps than the sper- 

 mophile. In the chapter on zoology I have described the trench 

 used for keeping gophers out of orchards and gardens, and for 

 catching them. 



The grasshoppers are the greatest pests of the farmer in 

 California, and several times during the last fifteen years they 

 have eaten every green thing within large districts. They 

 come in millions upon millons, and darken the air, moving for- 

 ward at the rate of a mile or two a day, and leaving no grass 

 or leaf behind them. Grains, grass, weeds, kitchen vegetables, 

 and fruit trees, are alike eaten bare of every green particle. 

 Grasshoppers are abundant in countries where the summers are 

 dry, the winters warm, and the vegetation vigorous ; and if a 

 large extent of land be uncultivated, they will occasionally be 

 so numerous as to destroy every green thing. They are bred 

 in the hills of California, and after dry winters descend into 

 the valleys, usually content to eat the wild grasses, but some- 

 times attack the cultivated fields. There is no known method 

 of killing them after they have entered a field, or of driving 

 them away from it ; but they may be kept out by digging a 

 trench, putting straw in it, with some moist straw on top, and 

 then setting fire to it. The grasshoppers do not like the fire 

 and smoke, and will try to avoid them. 



Under the head of the grape and the orange, I have spoken 

 of the bugs which infest them. The army-worm and weevil 

 have been seen in California, but have done little damage as 

 yet. The curculio is not known in the State. The Canada 

 thistle, the mullen, and the dock, have been introduced, but 

 have not yet given much trouble. 



194. Irrigation. According to the State Surveyor-Gen- 

 eral's statistics for 1871, California had in that year 915 irri- 

 gating ditches, supplying water to 90,344 acres an average 

 of about 100 acres to the ditch. Siskiyou is credited with 180 

 ditches, and 6,900 irrigated acres; Tulare, with 110 ditches 



