(Table A1) Annual biomass of plants and animals recorded on Bylot Island between 1993-2009

Determining the manner in which food webs will respond to environmental changes is difficult because the relative importance of top-down vs. bottom-up forces in controlling ecosystems is still debated. This is especially true in the Arctic tundra where, despite relatively simple food webs, it is still unclear which forces dominate in this ecosystem. Our primary goal was to assess the extent to which a tundra food web was dominated by plant-herbivore or predator--rey interactions. Based on a 17-year (1993-2009) study of terrestrial wildlife on Bylot Island, Nunavut, Canada, we developed trophic mass balance models to address this question. Snow Geese were the dominant herbivores in this ecosystem, followed by two sympatric lemming species (brown and collared lemmings). Arctic foxes, weasels, and several species of birds of prey were the dominant predators. Results of our trophic models encompassing 19 functional groups showed that <10% of the annual primary production was consumed by herbivores in most years despite the presence of a large Snow Goose colony, but that 20-100% of the annual herbivore production was consumed by predators. The impact of herbivores on vegetation has also weakened over time, probably due to an increase in primary production. The impact of predators was highest on lemmings, intermediate on passerines, and lowest on geese and shorebirds, but it varied with lemming abundance. Predation of collared lemmings exceeded production in most years and may explain why this species remained at low density. In contrast, the predation rate on brown lemmings varied with prey density and may have contributed to the high-amplitude, periodic fluctuations in the abundance of this species. Our analysis provided little evidence that herbivores are limited by primary production on Bylot Island. In contrast, we measured strong predator-prey interactions, which supports the hypothesis that this food web is primarily controlled by top-down forces. The presence of allochthonous resources subsidizing top predators and the absence of large herbivores may partly explain the predominant role of predation in this low-productivity ecosystem.

Introduction to arthropods of public health importance.

"Prepared and printed 1960, revised 1969, 1971."

Arthropods of medical importance in Australia and the Pacific islands,

At head of title: Technical report 68-61-ES.

Epidemiology of the arthropod-borne viral encephalitides in Kern County, California, 1943-1952,

Bibliography: p. 243-257.

Classification of insects : a key to the known families of insects and other terrestrial anthropods /by Charles T. Brues and A. L. Melander.

Includes bibliographies.

Envenomization /

At head of title: CDC Training Program.

Neue Beiträge zur Arthropoden-fauna Norwegens nebst gelegentlichen Bemerkungen über Deutsche Arten. I-[XXVI]

Reprinted from Nyt Magazin f. Naturvidensk.

Laboratory manual for medical entomology.

Mimeographed.

Treatise on invertebrate paleontology /

"Treatise Online publishes chapters prepared for parts of the Treatise on Invertebrate Paleontology as they are ready, rather than waiting for an entire hard copy Treatise to be printed"--Treatise Online website

Arthropods of medical importance in Latin America /

Earth Sciences Laboratory ES-35.

Dr. H.G. Bronn's Klassen und Ordnungen des Thier-Reichs : wissenschaftlich dargestellt in Wort und Bild.

Imprint varies: some volumes have imprint: Leipzig: Akademische Verlagsgesellschaft.

Sur les organes excréteurs chez les arthropodes terrestres,

From the 1st pt. of the Travaux du Congrès international de zoologie à Moscou, en 1892.

Untersuchungen über Bau und Entwicklung der Arthropoden,

Mode of access: Internet.

A tabular view of the external characters of four classes of animals which Linnʹe arranged under Insecta : with the distribution of the genera composing three of these classes into orders &c. : and descriptions of several new genera and species /

Mode of access: Internet.

Characters of Embia, a genus of insects allied to the white ants (termites): with descriptions of the species of which it is composed /

Mode of access: Internet.