caa a22 4500 475838378 CHVBK 20180406123854.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1007/PL00012000 doi (NATIONALLICENCE)springer-10.1007/PL00012000 Causes of cyclicity of Epirrita autumnata (Lepidoptera, Geometridae): grandiose theory and tedious practice [Elektronische Daten] [K. Ruohomäki, M. Tanhuanpää, M. P. Ayres, P. Kaitaniemi, T. Tammaru, E. Haukioja] Creating multiyear cycles in population density demands, in traditional models, causal factors that operate on local populations in a density-dependent way with time lags. However, cycles of the geometrid Epirrita autumnata in northern Europe may be regional, not local; i.e., successive outbreaks occur in different localities. We review possible causes of cycles of E. autumnata under both local and regional scenarios, including large-scale synchrony. Assuming cyclicity is a local phenomenon, individual populations of E. autumnata display peaks but populations all over the outbreak range fluctuate in synchrony. This concept assumes that the peaks at most localities are so low that they do not lead to visible defoliation and easily remain unnoticed. In this scenario, populations are able to start recovery a few years after the crash, i.e., at the time of the mitigation of detrimental delayed density-dependent factors, such as delayed inducible resistance of the host plant or parasitism. In that case, the same factors that lead to crashes also explain the periodicity of cyclic fluctuations. According to the regional cyclicity scenario, different factors can be important in different phases of the cycle. The key is to identify the factors that tend to produce outbreaks with a periodicity of about 10 years. Initiation of the increase phase seems to coincide with maxima in sunspot activity, but causal connections remain unclear. Climatic factor(s) associated with the solar cycle could contribute to the large-scale geographic synchrony. The Society of Population Ecology and Springer-Verlag Tokyo, 2000 Key words Cyclic population dynamics nationallicence Host plant quality nationallicence Inducible resistance nationallicence Parasitism nationallicence Predation nationallicence Winter mortality nationallicence Ruohomäki K. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut Tanhuanpää M. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut Ayres M. P. Department of Biological Sciences, Dartmouth College, Hanover, NH, USA, US aut Kaitaniemi P. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut Tammaru T. Institute of Zoology and Botany, Riia, Tartu, Estonia aut Haukioja E. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut https://doi.org/10.1007/PL00012000 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00012000 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ruohomäki K. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut NATIONALLICENCE 700 1- Tanhuanpää M. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut NATIONALLICENCE 700 1- Ayres M. P. Department of Biological Sciences, Dartmouth College, Hanover, NH, USA, US aut NATIONALLICENCE 700 1- Kaitaniemi P. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut NATIONALLICENCE 700 1- Tammaru T. Institute of Zoology and Botany, Riia, Tartu, Estonia aut NATIONALLICENCE 700 1- Haukioja E. Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland Tel. +358-2-3335766; Fax +358-2-3336550 e-mail: kairuo@utu.fi, FI aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer