The Holbrook news., 1910-09-23

ding the country of such pests have been very favorable in every way Dr. l.. O. Howard, head of the bureau of entomology at Washington, the larg- est and most efficient organization of its kind in the world, has become the leading exponent and the acknowl- edged expert of the cult Of setting an insect to kill an insect-the science of parasitology.
 The method used by Dr. Howard is to suppress the harmful insects and to foster the useful ones, that Is to de stroy the destroyers by abetting the destroyers of the destroyers Thus has arisen a new and ingenious branch of scientific endeavor, the ex- pert culture of insect parasites. AL ready number of the most important tests have been reduced to innocu- ousness by the insects of prey which have been set upon the trail; and while many others must still be com bated imperfectly by artificial meth ods, relentless science is securing the world for the tiny many-legged hounds which shall eventually hunt them down.
 Theoretically every insect has Its own specific enemy or enemies. These may prey upon it directly as certain beetles prey upon the larvae of the oliage-destroying moths; or they may feed upon it's eggs, as Is the case with many ladybirds, or they may deposit their own eggs either within the body or the egg of the victim, thereby de- stroyfng the immediate or prospective generation. Always these enemies tend to keep the insect pests within normal limitations. Doubtless in many cases the parasite would wholly destroy a species were 1t not for the existence of hyper-parasites which prey upon 1t and keep it from overex- pansion. In a state of nature this balance between the various species is automatically preserved until man with his ignorance of their nature en- ters and disturbs the whole status.
 Insect immigration has been the curse of American agriculture. Of our 72 importantly destructive species those whose destructive powers amount up to millions of dollars annu- ally-35 have come to us from other countries. The coddling moth, the curse of apple and pear orchards, is of European origin. The dreaded cot ton boll-weevil halls from Mexico. The San Jose scale comes from the immemorial east. The gypsy moth and the brown-tail moth, twin plaques of New England trees. were brought in by accident from the old world.
 As soon as an imported insect shows signs of becoming formidable, experts trace 1t from country to coun- try until they find a region where 1t has been known for a long time, but has never reached the proportions of a pest. In such place they are pret- ty sure to find a parasite which Is keeping the depredator down. If they can acclimatize that parasite and es- tablish 1t side by side with the i'm portation, the problem is solved. Such was the method in the case of the white or f1uted scale invasion of Cali fornia. The scale was imported by a collector of plants at San Jose, prob ably from Australia. In a few years 1t had spread enormously and was simply wiping out the orange crop wherever it gained a foothold. Work ing in conjunction with the progress sive state authorities of California the United States bureau of entomology sent an emissary to Australia, where the scale was discovered in what was then supposed to be its original en- vironment. With the Australian scale. and preying upon its eggs, was found a small red-and-black ladybird, the Novius cardinalis. One hundred of these were brought back to Califor- nit, bred and distributed. To the ter rified and skeptical orange growers