Cycles in insect populations: delayed density dependence or exogenous driving variables?
Version of Record online: 4 JAN 2002
Blackwell Science Ltd, Oxford
Volume 23, Issue 2, pages 216–222, May 1998
How to Cite
HUNTER , M. D. and PRICE , P. W. (1998), Cycles in insect populations: delayed density dependence or exogenous driving variables?. Ecological Entomology, 23: 216–222. doi: 10.1046/j.1365-2311.1998.00123.x
- Issue online: 4 JAN 2002
- Version of Record online: 4 JAN 2002
- Cited By
SummaryDelayed density dependence, and the cycles in insect populations that it can generate, are often investigated using time-series analysis. Recently, several authors have raised concerns about the validity of using time-series analysis to detect density dependence. One particular concern is the suggestion that exogenous driving variables, such as cyclic weather patterns, can lead to the spurious detection of density dependence in natural populations.
Using non-biological data (the electricity bills of one of the authors), we show how easy it is to be misled by the results of time-series analysis. We then present 16 years’ data on the gall-forming sawfly, Euura lasiolepis (Hymenoptera: Tenthredinidae), and show that cycles in weather, specifically winter precipitation, lead to the spurious detection of density dependence in time-series analysis. We conclude that time-series analysis cannot stand alone as a method for inferring the action of density dependence, and urge further investigation of the effects of apparent cycles in abiotic forces on insect populations.