snoopy9438
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Dołączył: 14 Lut 2011
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 Wysłany: Czw 12:29, 31 Mar 2011 Temat postu: black high heels silent+springnvf |
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ol of the Japanese beetle, farmers discovered that corn borers had increased enormously in the treated area. In fact [link widoczny dla zalogowanych], corn grown in fields within this area contained almost twice as many of the destructive larvae of this insect as did the corn grown outside. The farmers may not yet be aware of the biological basis of what has happened [link widoczny dla zalogowanych], but they need no scientists to tell them they have made a poor bargain. In trying to get rid of one insect, they have brought on a scourge of a much more destructive one. According to Department of Agriculture
estimates, total damage by the Japanese beetle in the United States adds up to about 10 million dollars a year, while damage by the corn borer runs to about 85 million.
It is worth noting that natural forces had been heavily relied on for control of the corn borer. Within two years after this insect was accidentally introduced from Europe in 1917, the United States Government had mounted one of its most intensive programs for locating and importing parasites of an insect pest. Since that time 24 species of parasites of the corn borer have been brought in from Europe and the Orient at considerable expense. Of these, 5 are recognized as being of distinct value in control. Needless to say [link widoczny dla zalogowanych], the results of all this
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