Kivelä, S., Viinamäki, S., Keret, N., Gotthard, K., Hohtola, E., Välimäki, P. (2017) Elucidating mechanisms for insect body size: partial support for the oxygen-dependent induction of moulting hypothesis. Journal of Experimental Biology, 221 (2), jeb166157. doi:10.1242/jeb.166157
Elucidating mechanisms for insect body size : partial support for the oxygen-dependent induction of moulting hypothesis
|Author:||Kivelä, Sami M.1; Viinamäki, Sonja2; Keret, Netta2;|
1Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu
2Department of Ecology and Genetics, University of Oulu
3Department of Zoology, Stockholm University
|Online Access:||PDF Full Text (PDF, 0.4 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe201802163464
Company of Biologists,
|Publish Date:|| 2019-01-25
Body size is a key life history trait, and knowledge of its mechanistic basis is crucial in life history biology. Such knowledge is accumulating for holometabolous insects, whose growth is characterised and body size affected by moulting. According to the oxygen-dependent induction of moulting (ODIM) hypothesis, moult is induced at a critical mass at which oxygen demand of growing tissues overrides the supply from the tracheal respiratory system, which principally grows only at moults. Support for the ODIM hypothesis is controversial, partly because of a lack of proper data to explicitly test the hypothesis. The ODIM hypothesis predicts that the critical mass is positively correlated with oxygen partial pressure (PO2) and negatively with temperature. To resolve the controversy that surrounds the ODIM hypothesis, we rigorously test these predictions by exposing penultimate-instar Orthosia gothica (Lepidoptera: Noctuidae) larvae to temperature and moderate PO2 manipulations in a factorial experiment. The relative mass increment in the focal instar increased along with increasing PO2, as predicted, but there was only weak suggestive evidence of the temperature effect. Probably owing to a high measurement error in the trait, the effect of PO2 on the critical mass was sex specific; high PO2 had a positive effect only in females, whereas low PO2 had a negative effect only in males. Critical mass was independent of temperature. Support for the ODIM hypothesis is partial because of only suggestive evidence of a temperature effect on moulting, but the role of oxygen in moult induction seems unambiguous. The ODIM mechanism thus seems worth considering in body size analyses.
Journal of experimental biology
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1181 Ecology, evolutionary biology
1184 Genetics, developmental biology, physiology
This study was financed by the Finnish Cultural foundation (S.M.K), the Emil Aaltonen Foundation (S.M.K), the Estonian Research Council (PUT1474 to S.M.K), Thule Institute (N.K.), the Bolin Centre for Climate Research at Stockholm University (K.G.), and the Knut and Alice Wallenberg Foundation (2012.0058 to K.G.).
© 2017 The Authors. Published by The Company of Biologists Ltd.