September, 1909] 



19S 



REVIEW. 



"Economic Loss to the People ot the 

 United States through Insects that 

 carry Disease." By L. O. Howard, Ph. D., 

 Chief of the Bureau of Entomology, 

 U.S.A. 



Under the above title, Dr. Howard 

 has published a most important circular 

 (of 38 pages), in which he brings forward 

 overwhelming evidence of the maleficent 

 agency of certain insects in the disse- 

 mination of disease. 



In his introduction, he instances the 

 now generally accepted (and— in many 

 cases—fully demonstrated) connection 

 between 



(1) The Anopheles mosquito and Mala- 

 rial Fevers ; 



(2) The Mosquito Stegomyia fasciata 

 and ' Yellow Fever ' ; 



(3) Certain species of Culex and Filari- 

 asis (including Elephantiasis) ; 



(4) The House Fly and Typhoid Fever, 

 Asiatic Cholera, Dysentery, Purulent 

 Ophthalmia and Tuberculosis ; 



(5) The Rat-Flea and Bubonic Plague . 



(6) The 'Tsetse Fly' and 'Sleeping 

 ickness ' : 



to say nothing .of the conveyance of 

 numerous dangerous diseases of domestic 

 animals by ticks and other insects. 



Dr. Howard draws attention to the 

 fact that Mosquitoes are responsible for 

 considerable monetary loss in other 

 ways than as carriers of disease. 

 " Possibly the greatest of these losses is 

 in the reduced value of real estate in 

 mosquito-infested regions, since these 

 insects render absolutely uninhabitable 

 large areas of land available for suburban 

 homes, for summer resorts, for manu- 

 facturing purposes, and for agricultural 

 pursuits," " All over the United States, 

 t'oi these insects, and for the house fly as 

 well, it has become necessary at great 

 expense to screen habitations." 



Malaria. 



After describing the ravages of malaria 

 in different parts of the world, and 

 pointing out that, besides actual loss of 

 life, it is the cause of enormous loss of 

 efficiency to labour in malarious local- 

 ities, the author goes on to emphasize 

 the fact that " malaria is a preventable 

 disease. It is possible for the human 

 species to live and to thrive and to 

 produce in malarious regions, but at a 

 very considerable inconvenience and 

 expense. The Italian investigators, and 

 especially Celli and his staff, have shown 

 that by screening the huts of the pea- 

 sants on the Roman Campagna and by 

 furnishing field labourers with veils and 



gloves when exposed to the night air, it 

 is possible even in that famous hotbed 

 of malaria to conduct farming operations 

 with a minimum of trouble from the 

 disease. Moreover, Koch and his assis 

 tants in German East Africa have shown 

 that it is possible, by stamping out the 

 disease amongst human beings by the 

 free use of medecine, that a point can 

 be gained where there is small oppor- 

 tunity for the malarial mosquitoes to 

 become infected. Moreover, the work 

 of the parties sent out by the Liver- 

 pool School ot Tropical Medicine and 

 other English organizations to the 

 west coast of Africa has shown that 

 by the treatment of malarial-mosquito 

 breeding pools the pernicious coast 

 fever may be greatly reduced. Again, 

 the work of Englishmen in the Federated 

 Malay States has shown that large areas 

 may be practically freed from malaria. 

 The most thorough and satisfactory of 

 all measures consists in abolishing the 

 breeding places of the malarial mosqui- 

 toes. With a general popular appreci- 

 ation of the industrial losses caused 

 primarily by the malarial mosquito, 

 and secondarily by the forms which 

 do not carry malaria, as indicated in 

 the opening paragraphs, it is incon- 

 ceivable that the comparatively inex- 

 pensive measures necessary should not 

 be undertaken by the General Govern- 

 ment, by the State Governments, and by 

 the boards of health of communities just 

 as it is inconceivable that the individual 

 should suffer from malaria and from the 

 attacks of other mosquitoes when he has 

 individual preventives and remedies at 

 hand." 



A few excellent examples of anti- 

 malarial work may be instanced. 



" The latest reports on the measures 

 taken to abolish malaria from Klang and 

 Port Swettenham in Selangor, Federated 

 Malay States, indicate the most admir- 

 able results. These measures were 

 undertaken first in 1901 and 1902, and 

 have been reported upon from time to 

 time in the Journal of Tropical Medicine. 

 The expenditure undertaken by the 

 Government with a view to improving 

 the health of the inhabitants of these 

 towns has been fully justified by the 

 results, which promise to be of per- 

 manent value. The careful tabulation 

 of cases of deaths and of the results 

 of the examination of blood of children 

 in especially drained areas indicates 

 the following conclusions : (1) Measures 

 taken systematically to destroy breed- 

 ing places of mosquitoes in these 

 towns, the inhabitants of which suffered 

 terribly from malaria, were followed 

 almost immediately by a general 

 improvement in health and decrease in, 

 death rate. 



