Page:Popular Science Monthly Volume 45.djvu/701

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PARASITIC AND PREBACEOUS INSECTS. 681

was very great indeed." Mr. William F. Channiug, of Pasadena, son of tlie eminent Unitarian divine, wrote two years later :

" We owe to the Agricultural Department tlie rescue of our orange culture by tlie importation of the Australian ladybird ( Vedalia cardinal is).

" The white scales were incrusting our orange trees with a hideous lepros5^ They spread with wonderful rapidity, and would have made citrus growth on the whole North American continent impossible within a few years. It took the vedalia, when intro- duced, only a few years absolutely to clean out the white scale. The deliverance was more like a miracle than anything I have ever seen. In the spring of 1889 I had abandoned my young Washington navel orange trees as irrevocable. Those same trees bore from two to three boxes of oranges apiece at the end of the season (or winter and spring of 1890). The consequence of the deliverance is that many hundreds of thousands of orange trees (navels almost exclusively) have been set out in southern Cali- fornia this last spring."

In other words, the victory over the scale was complete, and will practically remain so. The history of the introduction of this pest ; its spread for upward of twenty years and the discour- agement which resulted ; the numerous experiments which were made to overcome the insect ; and its final reduction to unimpor- tant numbers by means of an apparently insignificant little beetle imported for the purpose from Australia, will always remain one of the most interesting stories in the records of practical ento- mology.

The vedalia has since been successfully colonized at the Cape of Good Hope and in Egypt, and has produced the same results in each case. In Egypt the vedalia was introduced to prey upon an allied species of icerya {I. mgypfiacum.). We hope soon to be able to send the same insect to India, where it has recently trans- pired that Icerya a^gyptiacuin occurs ; while recent information received from Phra Suriya, Royal Commissioner of Siam, at Chi- cago, would indicate that its introduction into Siam for the same or a closely allied insect will be desirable in the near future.

In fact, the success of the experiment was so striking and so important, and resulted in the saving to California of an indus- try of so great a money value that it has given rise, not only in the popular mind but in the minds of a certain class of entomolo- gists also, to the idea that remedial work against injurious insects should be concentrated upon this one line of action, and that our best hope for their destruction lies with the parasitic and preda- ceous species, not to mention fungous and bacterial diseases. From an extreme of comparative incredulity the farmer and fruit- grower have gone, perhaps, to the other extreme of too great

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