 | United States. Department of Agriculture - 1883 - 610 trang
...Slight overpoisoning seems to have a tonic or invigorating • effect on the tree. Preventive Effect« of the Poison. — In this grove the elms that were...region of Washington a preventive application of poison should be made before the last of May or first of June, when the eggs are being deposited and before... | |
 | 1883 - 632 trang
...once observable, no leaf-eater thrives upon the foliage. Slight overpoisoning seems to have a tome or invigorating effect on the tree. Preventive Effects...afterward became increased, probably by immigration arid the new generation, so that later in the season the trees were mostly infested to the usual extent.... | |
 | United States. Department of Agriculture - 1883 - 614 trang
...poisoned the previous year. This would seem to imply that the insects deposit mostly on the treefi nearest to where they develop, and are only partially...region of Washington a preventive application of poison should Ъе made before the last of May or first of June, when the eggs are being deposited and before... | |
 | United States Entomological Commission, Alpheus Spring Packard - 1890 - 1060 trang
...invigorating effect on the tree. Preventive Effects of the Poison. — In this grove the elms that wore poisoned in 1882 were attacked in the spring of 1883...region of Washington a preventive application of poison should be made before the last of May or first of June, when thn eggs are being deposited and before... | |
 | United States Entomological Commission - 1890 - 1078 trang
...on the tree. Preventive Effects of the Poison. — In this grove the elms that were poisoned in 18SJ were attacked in the spring of 1883 less severely...region of Washington a preventive application of poison should be made before the last of May or first of June, when the eggs are being deposited and before... | |
 | United States Entomological Commission, Alpheus Spring Packard - 1890 - 1058 trang
...seem to imply that the insects deposit mostly on the trees nearest to where they develop, and are ouly partially migratory before ovipositing. The attack...region of Washington a preventive application of poison should be made before the last of May or first of June, when the eggs are being deposited and before... | |
 | New York (State). State Entomologist - 1896 - 292 trang
...extent of four miles as measured from its southern to its northern boundary. As stated by Dr. Riley,* " the insects deposit mostly on the trees nearest to...are only partially migratory before ovipositing." On a short tour of inspection made on August 26th, there were found on Myrtle avenue, near Philip street,... | |
 | 1896 - 786 trang
...extent of 4 miles as measured from its southern to its northern boundary. As stated by Dr. Riley,* "the insects deposit mostly on the trees nearest to...are only partially migratory before ovipositing." On a short tour of inspection made on August 26 there were found on Myrtle avenue, near Philip street,... | |
 | United States. Bureau of Entomology - 1883 - 682 trang
...that were poisoned in 1882 were attacked in the spring of 1883 less severely than were those whicb were not poisoned the previous year. This would seem...so that later in the season the trees were mostly intested to the usual extent. In the region of Washington a precentivc application of poison should... | |
 | 1895 - 108 trang
...extent of 4 miles as measured from its southern to its northern boundary. As stated by Dr. Riley,* "the insects deposit mostly on the trees nearest to...are only partially migratory before ovipositing." On a short tour of inspection made on August 26 there were found on Myrtle avenue, near Philip street,... | |
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This would seem to imply that the insects deposit mostly on the trees nearest to where they develop, and are only partially migratory before ovipositing. The attack afterward became increased, probably by immigration and the new generation, so that later... 