TY  - JOUR
A1  - Heisswolf, Annette
A1  - Käär, Miia
A1  - Klemola, Tero
A1  - Ruohomäki, Kai
T1  - Local outbreaks of Operophtera brumata and Operophtera fagata cannot be explained by low vulnerability to pupal predation
T2  - Agricultural and Forest Entomology
N2  - One of the unresolved questions in studies on population dynamics of forest Lepidoptera is why some populations at times reach outbreak densities, whereas others never do. Resolving this question is especially challenging if populations of the same species in different areas or of closely-related species in the same area are considered. The present study focused on three closely-related geometrid moth species, autumnal Epirrita autumnata, winter Operophtera brumata and northern winter moths Operophtera fagata, in southern Finland. There, winter and northern winter moth populations can reach outbreak densities, whereas autumnal moth densities stay relatively low. We tested the hypothesis that a lower vulnerability to pupal predation may explain the observed differences in population dynamics. The results obtained do not support this hypothesis because pupal predation probabilities were not significantly different between the two genera within or without the Operophtera outbreak area or in years with or without a current Operophtera outbreak. Overall, pupal predation was even higher in winter and northern winter moths than in autumnal moths. Differences in larval predation and parasitism, as well as in the reproductive capacities of the species, might be other candidates.
KW  - Epirrita autumnata
KW  - forest Lepidoptera
KW  - Operophtera brumata
KW  - Operophtera fagata
KW  - outbreak
KW  - population dynamics
KW  - pupal predation
KW  - Finland
Y1  - 2013
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/30115
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-301155
N1  - Postprint version. Original publication in: Agricultural and Forest Entomology (2010) 12(1): 81-87; doi: 10.1111/j.1461-9563.2009.00455.x
VL  - 12
IS  - 1
SP  - 81
EP  - 87
ER  -