Kozlov M.V., Oudendijk Z., Forsman A., Lanta V., Barclay M. V. L., Gusarov V. I., Gustafsson B., Huang Z.-Z., Kruglova O. Y., Marusik Yu. M., Mikhailov Yu. E., Mutanen M., Schneider A., Sekerka L., Sergeev M. E., Zverev V., Zvereva E. L.
В журнале Insect Science
Год: 2021
Colour polymorphism offers rich oppo 40 rtunities for studying the eco-evolutionary 41 mechanisms that drive the adaptations of local populations to heterogeneous and changing 42 environments. We explored the colour morph diversity and composition in a Chrysomela 43 lapponica leaf beetle across its entire distribution range to test the hypothesis that 44 environmental and climatic variables shape spatio-temporal variation in the phenotypic 45 structure of a polymorphic species. We obtained information on 13 617 specimens of this 46 beetle from museums, private collections and websites. These specimens (collected from 47 1830–2020) originated from 959 localities spanning 33 degrees latitude, 178 degrees 48 longitude and 4200 m altitude. We classified the beetles into five colour morphs and searched 49 for environmental factors that could explain the variation in the level of polymorphism 50 (quantified by the Shannon diversity index) and in the relative frequencies of individual 51 colour morphs. The highest level of polymorphism was found at high latitudes and altitudes. 52 The colour morphs differed in their climatic requirements; their composition was independent 53 of the geographic distance that separated populations but changed with collection year, 54 longitude, mean July temperature and between-year temperature fluctuations. The proportion 55 of melanic beetles, in line with the thermal melanism hypothesis, increased with increasing 56 latitude and altitude and decreased with increasing climate seasonality; it also declined during 57 the past century, but only at high latitudes and altitudes where recent climate warming was 58 especially strong. The observed patterns suggest that colour polymorphism is especially 59 advantageous for populations inhabiting unpredictable environments, presumably due to the 60 different climatic requirements of coexisting colour morphs.
