Smirnoff, W.A., & Valéro, J. 1975 [Effects of fertilization by urea nitrogen or potassium on Pinus banksiana L. and the behavior of destructive insects such as Neodiprion swainei (Hymenoptera, Tenthredinidae) and Toumeyella numismaticum (Homoptera, Coccidae).]. Canadian Journal of Forest Research 5: 236-244.

Notes: [Original title: Effets à moyen terme de la fertilisation par urée ou par potassium sur Pinus banksiana L. et le comportement des ses insectes dévastateurs: tel que Neodiprion swainei (Hymenoptera, Tenthredinidae) et Toumeyella numismaticum (Homoptera, Coccidae).] This study focuses on the effect of fertilization on the physiology of jack pine in a natural stand, and its two important foliage pests. It was observed that urea fertilization, even at low dosage, favored T. numismaticum, this infestation 2, 7 and 9 times in plots fertilized with 100, 200 and 400 kg of urea nitrogen per hectare. The studies revealed, however, that fertilization with potassium may reduce T. numismaticum. The infestation in the fertilized plot showed a reduction from 42 to 21%, and in the unfertilized plot there was an increase from 38 to 80%.