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Show KILL NUISANCES WITH WAR GASES Deadly Fumes Being Tried to Destroy De-stroy Noxious Birds, Animals Ani-mals and Insects. SOKE PROMISE TO BE USEFUL Migratory Blackbirds Do Damage Amounting to Thousands of Dollars Dol-lars in imperial Valley of California Cal-ifornia Injure Milo Crop. Prepared by th United States Department ot Agriculture.) Deadly gases that were developed for war purposes are now being tried out by the United States Department of Agriculture as a means for destroying destroy-ing noxious birds, animals, and insects. Some of them promise to be useful when applied under proper conditions, particularly those that are heavier than air and can be used on burrowing rodents, and possibly subterranean insects in-sects and pests In stored products. KIM Destructive Birds. The most recent proposal is to use gas to kill destructive birds Miat congregate con-gregate In marshes. In the coming fall the biological survey, in co-operation with the chemical warfare service, serv-ice, is planning to make a trial of the method on blackbirds In the Imperial valley cf California. In that region these birds are said to do at least $50,-000 $50,-000 worth of damage to the milo crop each year. Because of their feeding habits It Is Impossible to destroy these birds with poisoned baits, but, as they roost on the reeds in the marshes, It is thought that they can be killed by a gas cloud at night when the wind is favorable. The blackbirds are migratory migra-tory and return to the same places year after year. It is thought that a big killing in a certain locality will probably free it of the pests for many years. A few other birds in the blackbird-infested marshes will be killed at the same time, but the department believes be-lieves that these local birds will soon reach their normal numbers again. Try Gas on Rodents. Arrangements also are being made by the biological survey with the chemical chem-ical warfare service for investigating the possibility of using poison gases on such burrowing rodents as rats, prairie' dogs, ground squirrels, and woodchucks. Tests on pocket gophers 'and ground snulrrels bv these two co- 1 r BracKoiras Return to Same Place Tear After Year. operating branches of the government in California show that chlorine may be used with good results if handled properly. Tbe chemical warfare service serv-ice used phosgene on rats in Porto Itico with promising results. Some of these war gases will be compared with carbon bisulphide for the killing of woodchucks and other rodents In their burrows. Entomologists of the department have already worked In co-operation with the War department In testing various gases on insect pests of growing grow-ing plants and those that Infest stored grain, but It has not yet been found advisable to recommend anything lo take the place of hydrocyanic-acid gas or carbon bisulphide. The serious disadvantages of many of these new gases Is that they are dangerous or very irritating to men, horses, and mules, and require the use of masks and great care in handling. |