Illustrated identification guide to the Nordic aphids feeding on Conifers (Pinophyta) (Insecta, Hemiptera, Sternorhyncha, Aphidomorpha) Author Albrecht, Anders Christian text European Journal of Taxonomy 2017 2017-07-24 338 1 160 journal article 22023 10.5852/ejt.2017.338 be9f3ab9-3131-4e11-8d29-a94275ffaac9 2118-9773 3834349 86786AB1-4A1A-4A1E-B42B-53B73D66ED60 Pachypappa tremulae (Linnaeus, 1761) Diagnosis Holocyclic, dioecious, alternating between Populus tremula (Salicaceae) and Picea . Anholocyclic hibernation on roots of Picea is common. Recorded secondary hosts Pinaceae : Picea abies * , orientalis , sitchensis . Distribution D F N S.