The "wilt disease," of "flacherie," of the gypsy moth . m the ground, in order that thewind might aid in the spread of the disease. In plantingthe diseased material the direction of the prevailing wind of the * That this is the case is proved by some experiments which I shall consider particularly later,where only sick caterpillars were transplanted, but no dead caterpillars. 17 season was taken into consideration. For instance, in locali-ties which had prevailing east winds the infected materialwas exposed near the eastern border of the forest, but stillinside of it, so that the wind, before
The "wilt disease," of "flacherie," of the gypsy moth . m the ground, in order that thewind might aid in the spread of the disease. In plantingthe diseased material the direction of the prevailing wind of the * That this is the case is proved by some experiments which I shall consider particularly later,where only sick caterpillars were transplanted, but no dead caterpillars. 17 season was taken into consideration. For instance, in locali-ties which had prevailing east winds the infected materialwas exposed near the eastern border of the forest, but stillinside of it, so that the wind, before reaching the larger partof the wood, was forced to strike first the center of the diseasedarea. It may be mentioned that in some cases, where no con-venient cloth was at hand, the breeding cages themselves withthe material, after the removal of the cover, were hung betweenlimbs. No difference was observed in the results. The in-fected material was planted in most of the localities at a timewhen most of the caterpillars in the field were undergoing the. Fig. 1.— Method of hanging hammook in tree. third molt. The respective ages of the caterpillars will bementioned under each experiment.^ It was important to select places which gave the best guaran-tee for the health of the growing caterpillars; hence, specialattention is called to the fact that in the experimental localitiesno disease is known to have occurred among the caterpillarsof previous years. I had always planned to plant the disease as soon as it made its appearance in one or the otherof the broods. This was, however, frustrated on several occasions by various instance, some local superintendents did not notice the Flacherie till after the disease hadprevailed for several days. It was, further, not always possible for me to depart immediatelyupon receiving a communication concerning the outbreak of the disease. It was also almostimpossible for one man to transplant the infected material to all the ch
Size: 2147px × 1164px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectgypsymoth, bookyear19
