. Injurious insects : how to recognize and control them . Insect pests; Insect pests. TRAys^rIssIox of disease 43 ment later comes through our opeueil doors or unscreeneii windows, its hairy feet loaded with dangerous germs, and alights on the food set on our dinner table. Or, coming from the street, where it has been feeding on the sputum of some unfortunate \'ictim of tuberculosis, it brings in the deadly bacteria in the ridges and hollows of its tongue. Mosquitoes In a wholly different manner the mosquitoes of certain species have been proved to transmit malarial fever. Indeed it is known t
. Injurious insects : how to recognize and control them . Insect pests; Insect pests. TRAys^rIssIox of disease 43 ment later comes through our opeueil doors or unscreeneii windows, its hairy feet loaded with dangerous germs, and alights on the food set on our dinner table. Or, coming from the street, where it has been feeding on the sputum of some unfortunate \'ictim of tuberculosis, it brings in the deadly bacteria in the ridges and hollows of its tongue. Mosquitoes In a wholly different manner the mosquitoes of certain species have been proved to transmit malarial fever. Indeed it is known that this disease never is transmitted in any other way. Here, in contrast to tlie fly which simply carries germs mechanically on some part of its body, ^\â e have an Insect that serves as an intermediary host to the organism, the latter going through a definite part of its life roimd withiu the body of the insect, the remainder within the body of man. The mosquito itself is infected by sucking the blood of a htmian being sutTering from malaria. The orgauisnt that causes the disease, being thus transferred to the stomach of the insect, goes through certain changes, and eventually collects in large mmibers in the salivary gland of the mosquito. If, now. this insect bites another person, the organisms are transferred to the latter, and shortly develop in the blood, giving rise to the characteristic chills and fever, recurring at regular intervals, according to the particular type of organism with which the mosquito has been infected. As a direct result of this knowledge it has been possible to bring about phenomenal results in fever-ridden districts, b>- careful screening, and by isolating fever patients so that mosquitoes could not get at them while they were suffering from the disease. In places where this. Fig. 43.âA iiialarial niosqviito, An- oplichs mnciilipcnnis Enlarged and natural size. Please note that these images are extracted from scanned page ima
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsectp, bookyear1912
