PRACTICAL AND POPULAR ENTOMOLOGY.—NO. 19.: How Insects are Distributed
llre are all au'are that there are many insects in our country to-day that were unknorvr.r here a ferv years ago. tr-ven rniddie-aged men and women of onr farrring comrnunity can rvell rernember the time when there were no Colorado beetles (potato bLrgs), no cabbage btttterflies, no l)ea weevils, and no San Josd Sca.le to rvorry their minds, The fact is that the majority of our worst in:ect pests are not native. but have been introduced either from Er.rrope or the United States, many of the
... es, many of the latter coming originally from ELrropean or other foreiqn sources. l'l-re follorving very incompleie list of impcrted insects rvill n'rake this pcint clear: Codling moth, cabbage butterfly, curr,tnt rvorm, Hessian fly, rvheat midge, cJover weevil, both kinds of asparagus beetles, Colorado beetle, horn fly, Buffalo carpet beetle, house cockroach, nrost of our plant lice or aphides, white fly, oyster-sheil and,san Josi scales, and nrost of oiir qranary pests a.ud meal worms, as they are commouly called. Of these injurious insects nore than three-qLrarters have come to us fronr Er-rrope through the United States, thougl-r one of the worst, the San Jos6 Scale, has been traced back to China. But even in the case of the European importations, it is probable that mary of them had their original home in tl.re still earlier civilized portion oI the continents of Asia and Afirica, whence they sp[ead to Europe and no\y have come to us.