|
LIST OF ORNAMENTAL PLANTS SUBJECT TO DISEASE AND INSECT PESTS Not all trees are equally seriously affected by insect pests and in thelist below where a long list of insects and diseases are given after a plantname it does not signify that all those insects and diseases commonlyoccur, but merely that they are known to occur on one or more speciesof the genus. The list is given merely as a guide showing along whatlines to look for further information, and it also indicates the sort oftreatment required as outlined in the chapter on Maintenance, underthe spraying discussion (See Page 75). Considerable study throughout New York and Ohio in regardto the immunity of trees from insect injury points to the following con-clusions: The arborvitae, tree of heaven, and the ginkgo are practi-cally immune from injurious insects. The American and Orientalplanes, the red and scarlet oaks, and the tulip tree and junipers areoccasionally attacked. The red, Norway, sugar, and sycamore maples,the white and bur oaks, the honey locust, catalpa, the birches, thespruces, and the white pine have each one serious insect pest. Amongthe trees very likely to be attacked by insects are the European andAmerican lindens, the American and the water or red elms, the softmaple, the horse-chestnut and buckeyes, and the hackberry. TheEuropean and Scotch elms and the willows are very seriously injuredby insects, while the yellow locusts and poplars and cottonwoods are soseriously injured as to make it doubtful whether they should ever beused in ornamental planting. |
|||
|
