Page:Popular Science Monthly Volume 89.djvu/382

 Raising Parasites to Fight Pests

���Structure Erected in Connection with the Parasite Laboratory Where the Gypsy Moth and Other Pests Are Trapped and Studied

��MANY methods of exterminating injurious insects have been tried, some proving useless and others, while effective, being only temporarily so. Perhaps the most scientific work 3'etattempted is thecultivationof natural enemies, which in time would annihilate the insects upon which they live. The gipsy moth and brown-tail moth are particularly injurious. Both are natives of Europe and were early introduced into Massachusetts, where they have committed yearly ravages on fruit and shade trees. Can no enemy which will devour them be found?

In 1905, work was begun under Federal supervision to answer that question. Dr. L. O. Howard, chief of the Bureau of Entomology, and Dr. W. F. Fiske, in charge of the Gipsy Moth Parasite Laboratorj', Melrose Highlands, Mass., have expended time and energy in their unceasing efforts to rid the country of these harmful insects.

While at least a dozen parasites have been reared from the gipsy moth, and although a variety of American parasites are natural enemies, the aggregate effectiveness of all the species together is wholly insignificant. It is possible, how- cver, that the caterpillars may be attack- ed by parasites, the larvae of which may be rendered unable to complete their transformations under the conditions in which they find themsches.

Since insects like the gipsy moth and the brown-tail moth are subjected to the

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