The population growth of an endangered butterfly species is greatest in habitats with microclimatic variability, demonstrates a study carried out collaboratively by the Faculty of Biological and Environmental Sciences and the Helsinki Institute of Life Science of the University of Helsinki as well as the Finnish Environment Institute.
Insects are often very restricted in their capacity for movement. In many species, specific stages of life are spent entirely immobile, making them dependent on the temperature and moisture conditions of their immediate surroundings. In the Åland Islands on the southwest coast of Finland, Glanville fritillary butterflies (Melitaea cinxia) spend roughly 10 months of the year in the larval stage. In the middle of summer, the newly hatched larvae eat, as a group, the host plant, on whose leaf the female happened to lay the eggs. Prior research has shown that plants can wither entirely in dry summers, with prolonged dry periods sealing the fate of butterfly larvae. In such cases, only those larvae survive whose eggs have been laid on a plant growing in an exceptionally moist spot. MORE