Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomolo00smit Year: 1906 I20 ECOXOMIC ENTOMOLOGY. really necessary, since the treatment to be adopted is nearly the same in all cases. On deciduous trees, where the scales remain during the winter upon trunks and branches, and where the trees become dormant, the scales are best treated during the winter. At that time there is no foliage to interfere, and we can use much stronger washes than would be safe during the summer,
Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomolo00smit Year: 1906 I20 ECOXOMIC ENTOMOLOGY. really necessary, since the treatment to be adopted is nearly the same in all cases. On deciduous trees, where the scales remain during the winter upon trunks and branches, and where the trees become dormant, the scales are best treated during the winter. At that time there is no foliage to interfere, and we can use much stronger washes than would be safe during the summer, or when the tree is active. I have already called attention to the fact that it is difficult to penetrate insect tissues with ordinary liquids, and it has been found impossible in practice to obtain good results in the destruction of scale insects except by means of caustics. Potash and soda have FJ<^- 9°- been used with good effect even in a simple water\' mixture, but more satis- factorily in the form of very caustic soap. Whale, or other fish-oil soap, at the rate of two pounds in one gallon of water, as a winter wash, has proved absolutely effective against the San Jos6 scale and the oyster-shell bark-louse, two of the most resistant of the armored scales. The simple muriate of potash used as a fertil- izer has proved effective against the scurfy scale, while common laundry soap has been efficient against others of the softer species. The common soaps are all caustic, and, when applied at the strength indicated, the scale is shrivelled, lifted, and partially corroded, so that the oily mixture works its way beneath, into absolute contact with the insect. Or it is raised at the edges and washed off by the rains, carrying with it either eggs or young, as the case may be. In fact, where the eggs hibernate winter applications act only by exposing them, so that they are easily washed away by rains and scattered, under no proper condition to hatch. Or. should they hatch, the l
Size: 1443px × 1386px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
