This is a PDF of an old book on Greenhouse Pests, I am offering the PDF of a book long out of copyright for free, but if you prefer another person (whom I have no contact or dealings with) has taken this book and reprinted it sale on Amazon – you can see a link in the picture to your left.
Excerpt from Greenhouse Pests: A Manual of Practice in the Control of Insects and Other Pests Attacking Ornamental Plants and Flowers Grown Under Glass in Illinois
In the state as a whole, the total damage done by insects and other injurious forms of animal life is estimated at present to range from 10% to 25% of the value of all the ﬂowers and Ornamentals grown under glass. Assuming 1570 as a fair average reduction, we can safely say that the annual crop would be worth more than it is now if the industry did not have to pay tribute to these pests.
No crop is without its pests, and some have a dozen or more, so that the grower must be on his guard day and night through the grow ing season and even throughout, the year, in order to prevent all his profits from being literally eaten Up by one or another of these insidious enemies. Now the roots are attacked, now the stems and leaves, and now the ﬂowers themselves. Sometimes only a few plants may be injured; again a whole crop may be wiped out. It is probably true that no single operation in the greenhouse yields as large returns as that which checks the depredations of insects, since any one of the major pests would be able to destroy a crop, commercially, before it could be matured if no control measures were applied.Greenhouse Pests