Temperature- and density-dependence of diapause induction and its life history correlates in the geometrid moth Chiasmia
- PDF / 435,148 Bytes
- 17 Pages / 439.37 x 666.142 pts Page_size
- 10 Downloads / 130 Views
Temperature- and density-dependence of diapause induction and its life history correlates in the geometrid moth Chiasmia clathrata (Lepidoptera: Geometridae) Panu Va¨lima¨ki • Sami M. Kivela¨ • Maarit I. Ma¨enpa¨a¨
Received: 24 October 2012 / Accepted: 23 March 2013 / Published online: 8 June 2013 Ó Springer Science+Business Media Dordrecht 2013
Abstract The relative roles of genetics and developmental plasticity in creating phenotypes adapted to prevailing conditions are insufficiently understood. In potentially multivoltine temperate insects, individuals that do not enter diapause but develop directly into reproductive adults within the same season are severely time-constrained. Direct development is, however, under selection only if expressed in the wild. Thus, adaptive correlates of the direct development are expected to evolve and persist only in multivoltine populations. We studied the genetic and phenotypic components of variation in juvenile development in the geometrid moth Chiasmia clathrata from univoltine and bivoltine regions. Larvae were reared at two temperatures (14/20 °C) and densities (low/high) in a factorial split-brood experiment. High temperature and low density promoted direct development, the former condition being associated with a short development time, high growth rate and large body size. Genotypes of bivoltine origin had a higher propensity for direct development and seemingly expressed an exaggerated plastic response to increasing temperature compared to the ones from univoltine populations. Alternative life history phenotypes associated with the induced developmental pathway emerged only in the bivoltine region, direct development resulting in a short larval period, high growth rate and small size at 20 °C there. The degree of differentiation between the developmental pathways was insensitive to larval density; high density only decreased both development time and body size to a certain degree. We conclude that the differences between the pathways are not due to the induction of a particular pathway itself, but geographically varying
Electronic supplementary material The online version of this article (doi:10.1007/s10682-013-9657-8) contains supplementary material, which is available to authorized users. P. Va¨lima¨ki (&) S. M. Kivela¨ M. I. Ma¨enpa¨a¨ Department of Biology, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland e-mail: [email protected] Present Address: M. I. Ma¨enpa¨a¨ Institute of Evolutionary Biology, University of Edinburgh, Kings Buildings, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK
123
1218
Evol Ecol (2013) 27:1217–1233
selection pressures shape the correlation structure among life history traits and their pathway-specific expression. Keywords Developmental pathway Geographic variation Insects Phenotypic plasticity Thermal reaction norms
Introduction In seasonal environments, proper timing of life history events is crucial for ectotherms, such as insects, in synchronizing their development and reproduction with favoura
Data Loading...
