ENTOMOLOGY 395 



tion and quality of fruit has been fully restored. In this country it 

 will be particularly available in California and in all arid districts 

 where irrigation is practiced; otherwise it will be too expensive to 

 be profitable. The best results are secured in soils in which the 

 water will penetrate rather slowly, or from 6 to 18 inches in twenty- 

 four hours ; in loose, sandy soils it is impracticable on account of the 

 great amount of water required. Submersion consists in keeping 

 the soil of the vineyard flooded for from eight to twenty days after 

 the fruit has been gathered and active growth of the vine has ceased, 

 or during September or October, but while the phylloxera are still 

 in active development. Early in September eight to ten days will 

 suffice; in October fifteen to twenty days, and during the winter, 

 forty to sixty days. Supplementing the short fall submergence a 

 liberal July irrigation, amounting to a forty-eight hour flooding, is 

 customary to reach any individuals surviving the fall treatment, and 

 which in midsummer are very susceptible to the action of water. 



To facilitate the operation, vineyards are commonly divided by 

 embankments of earth into square or rectangular plats, the former 

 for level and the latter for sloping ground, the retaining walls 

 being protected by coverings of reed grass, etc., during the first year, 

 or until they may be seeded to some forage plant. 



This treatment will destroy many other root-attacking insects 

 and those hibernating beneath the soil, and, in fact, is a very ancient 

 practice in certain oriental countries bordering the Black Sea and 

 the Grecian Archipelago. 



REMEDIES FOR INSECTS AFFECTING GRAIN AND OTHER STORED 



PRODUCTS. 



General Methods of Treatment. The chief loss from insects of 

 this class is to grains in farmers' bins, or grain or grain products in 

 stores, mills, and elevators, although in the warmer latitudes much 

 injury results from infestation in the field between the ripening of 

 the grain and its storage in bins or granaries. Fortunately, the sev- 

 eral important grain insects are amenable to like treatment. Aside 

 from various important preventive operations, such as, in the South, 

 prompt thrashing of grain after harvesting, the thorough cleansing 

 of bins before refilling, removal of waste harboring insects from all 

 parts of granaries and mills, and care to prevent the introduction of 

 weeviled grain, there are four valuable remedial measures, viz, agita- 

 tion of the grain, heating, dosing with bisulphid of carbon, and 

 fumigating with sulphur dioxid. 



The value of agitating or handling grain is well known, and 

 whenever, as in elevators, grain can be transferred or poured from 

 one bin into another, grain pests are not likely to trouble. Tho 

 benefit will depend upon the frequency and thoroughness of the 

 agitation. In France machines for shaking the grain violently 

 have been used with success. Winnowing weeviled grain is also an 

 excellent preliminary treatment. 



Bisulphid of Carbon. This is a colorless liquid with very of- 

 fensive odor, which, however, passes off completely in a short time. 

 It readily volatilizes, and the vapor, which is very deadly to insect 



