caa a22 4500 46909852X CHVBK 20180323133038.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF00317692 doi (NATIONALLICENCE)springer-10.1007/BF00317692 Morris William Department of Zoology, NJ-15, University of Washington, 98195, Seattle, WA, USA aut The effects of natural enemies, competition, and host plant water availability on an aphid population [Elektronische Daten] [William Morris] Summary: I used a factorial experiment repeated in two years to assess the relative effects of natural enemy attack, interspecific competition, and water availability to the host plant, and of interactions among these factors, on the population dynamics of the aphid Aphis varians feeding on fireweed (Epilobium angustifolium). The impact of a suite of coccinellid and syrphid predators emerged as the predominant factor affecting the success of aphid colonies: colonies protected from natural enemies grew in size at a rate of ten percent per day, were only one tenth as likely to go extinct, and produced over ten times more dispersing alates. In contrast, I found only minor effects of removing flea beetles, the most abundant herbivore with which A. varians colonies cohabit fireweed stems, and of supplementing water availability to fireweed host plants, in spite of a significant effect of watering frequency on aphid growth in the green-house. There was no evidence of significant two- or three-way interactions among factors. Hence, despite the potential complexity of the food web in which it is embedded, the dynamics of A. varians appears to be driven predominantly by a single factor, i.e. interactions with natural enemies. Springer-Verlag, 1992 Aphis varians nationallicence Three trophic level interactions nationallicence Population dynamics nationallicence Higher-order interactions nationallicence Insect herbivores nationallicence Oecologia Springer-Verlag 90/3(1992-06-01), 359-365 0029-8549 90:3<359 1992 90 442 https://doi.org/10.1007/BF00317692 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317692 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Morris William Department of Zoology, NJ-15, University of Washington, 98195, Seattle, WA, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 90/3(1992-06-01), 359-365 0029-8549 90:3<359 1992 90 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer