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Variation in butterfly diapause duration in relation to voltinism suggests adaptation to autumn warmth, not winter cold
Author(s) -
Lindestad Olle,
Schmalensee Loke,
Lehmann Philipp,
Gotthard Karl
Publication year - 2020
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1111/1365-2435.13525
Subject(s) - voltinism , diapause , biology , butterfly , overwintering , ecology , polyphenism , local adaptation , ectotherm , population , adaptation (eye) , phenotypic plasticity , zoology , larva , demography , neuroscience , sociology
Abstract The life cycles of animals vary in relation to local climate, as a result of both direct environmental effects and population‐level variation in plastic responses. Insects often respond to the approach of winter by entering diapause, a hormonally programmed resting state where development is suspended and metabolism suppressed. Populations often differ in the duration of diapause, but the adaptive reasons for this are unclear. We performed a common‐garden overwintering experiment with respirometric measurements in order to investigate the progression of diapause in the butterfly Pararge aegeria . Both the duration of diapause and the depth of metabolic suppression were shown to vary between populations. In contrast to previous results from various insects, diapause duration did not correspond to the local length of winter. Instead, the observed pattern was consistent with a scenario in which diapause duration is primarily a product of selection for suppressed metabolism during warm autumn conditions. The relationship between optimal diapause duration and the length of the warm season is complicated by variation in the number of yearly generations (voltinism). These results shed new light on variation in diapause ecophysiology, and highlight voltinism as an integrated product of selection at multiple points in the seasonal cycle. A free Plain Language Summary can be found within the Supporting Information of this article.