Page:Popular Science Monthly Volume 70.djvu/333

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329
ECONOMIC IMPORTANCE OF MOSQUITOES

It is fair, therefore, to consider the mosquitoes of great economic importance, and as serious drawbacks to any community from three points of view:

First, their influence, direct and indirect, upon the health and well-being of the inhabitants.

Second, their influence upon the development of the agricultural resources, preventing or limiting the profitable use of infested territory for certain purposes.

Third, their influence upon land values due to the drawbacks mentioned under 1 and 2.

Having determined these points, it remains to determine whether, in any stage, any species of mosquito is of any value to man, directly or indirectly. The adult is a feeder upon juices of plants and animals; it produces nothing of use to us and removes nothing that is detrimental. It is of absolute importance to the continued existence of those microzoa that pass one stage of their existence in the mosquito body and nowhere else; but no one will argue that it is desirable to continue these organisms, and if the destruction of the mosquito is accompanied by the elimination of Plasmodia, Trypanosomes; Filaria and others of similar ills, a double good will have been accomplished.

In the larval stages the species are feeders upon the microorganisms, animal and vegetable, that occur in more or less stagnant waters. In a way they are scavengers, and it can not be definitely said that they may not destroy or limit some organisms that might otherwise be or become harmful to man. Could it be proved then that these stagnant water areas are necessary, it might be a question whether it is wise to war on mosquitoes until we have a more definite knowledge of the food of the wrigglers. But are these stagnant waters of any use to man, and is it necessary to retain them? On this point also it seems to me the answer must be against the insects, leaving absolutely no evidence that they are of any use or benefit whatever to the human race, directly or indirectly, as larva or adult.

The legislature and governor of New Jersey are sufficiently convinced of the injurious effects of the mosquito upon the development of the state to venture an investment of $350,000 in the effort to secure the practical elimination of the pest.