Articoli correlati a Orchard insect pests and methods of control
Sinossi
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 Excerpt: ...active, intelligent effort, rather than blind reliance upon an unknown factor, be made to prevent its gaining a good foothold. During the past fifteen years we have seen this idea of immunity dispelled in locality after locality, in the Pacific Northwest, and when we consider that the codling moth is a serious pest in England, on the continent of Europe from Mediterranean regions to the northern limits of apple growing in Siberia, in southern Africa, Australia, New Zealand, Tasmania and China, as well as in the United States and Canada, we are forced to recognize the improbability of perpetually immune regions. Once it gains a foothold the codling moth will thrive wherever the apple can be grown successfully. We do not wish to be understood as arguing that the codling moth will become equally destructive 'in all localities, or that its prevalence is independent of climatic conditions. Rather the contrary is true, since the seriousness of its depredations varies with both the locality and the season. Temperature is the great factor which controls the abundance of a species in a given locality; hence, as the female moth deposits eugs freely only when the evening temperature is above 60 degrees Fahrenheit, we should expect to find, as indeed we do find, that the orchards in the coast regions west of the Cascades, and those of the inland plateau sections, are less subject to the ravages of the codling moth than are those of the inland valleys. This factor is of but little practical importance, however, and should be given scant consideration in the selection of an orchard site. The probability is that as orchards become more numerous, active repressive measures against the codling moth will become necessary, even in the most favored localities. Know All Stages....
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