Inter-sexual and inter-generation differences in dispersal of a bivoltine butterfly

In organisms with discrete generations such as most insects, life-history traits including dispersal abilities often vary between generations. In particular, density-dependent differences in dispersal of bi- and multivoltine species may be expected because subsequent generations are usually characterized by a drastic increase in individual abundance. We investigated the inter-sexual and inter-generation differences in dispersal of a bivoltine butterfly, Lycaena helle, testing the following hypotheses: (1) male emigration is higher in spring generation, as males are prone to leave their natal habitat patches when the density of mating partners is low; (2) female emigration is higher in summer generation, when it helps to reduce intraspecific competition between offspring. The outcome of our analyses of dispersal parameters showed that females of the summer generation emigrated from their natal patches considerably more often than those of the spring generation, whereas an opposite trend was detected in males. These findings offer a novel perspective for our understanding of the advantages of voltinism for metapopulation functioning. The spring generation dispersal mainly improves the random mating opportunities favoured by the increase in male emigration. In turn, the dispersal of females of the summer generation appears the key to long-term metapopulation persistence.

Ontogenetic Basis of Among-Generation Differences in Size-Related Traits in a Polyphenic Butterfly

Seasonal polyphenisms are cases in which individuals representing generations occurring in different times of the year systematically differ in their morphological, physiological, and/or behavioral traits. Such differences are often assumed to constitute adaptive responses to seasonally varying environments, but the evidence for this is still scarce. The adaptive character of the response would be corroborated by the pattern in which the decision about choosing a particular seasonal phenotype is made before the onset of respective environmental conditions (anticipatory plasticity). Alternatively, the between-generation differences can be caused by immediate effects of seasonally varying environments (responsive plasticity). Here we reared the larvae of the seasonally polymorphic map butterfly Araschnia levana under two different photoperiodic regimes, which provided different seasonal cues. These two treatments induced direct development and diapause pathways, respectively. Replicating the experiment at different temperatures and levels of host plant quality allowed us to evaluate both the anticipatory and the responsive components of the associated plastic changes in life-history traits. Larvae representing the direct development pathway invariably had higher growth rates and shorter development periods, although the difference between the developmental pathways was smaller at inferior host quality. Body size differences between the developmental pathways turned out to be less consistent, as the natural pattern of higher pupal mass of the directly developing individuals could only be reproduced at lower rearing temperature. Though being considerably modified by immediate environmental effects, the between-generation differences in size, growth rates, and larval are largely based on anticipatory plasticity (= responses to photoperiodic cues) and should be treated as seasonal adaptations in A. levana. In a more general context, we show how investigating the proximate basis of size differences can serve the purpose of identifying the limits of phenotypic plasticity in juvenile growth schedules.

Identifying Generational Differences in Consumers' Decision to Use Shared Services in Russia

Digital transformation and rapid development of Internet technologies in the past decade have contributed to the emergence of an innovative business model of collaborative consumption [Sheresheva, Katsoni, 2019] and the spread of collaborative consumption services (CCS). This study attempts to identify the factors that influence consumers’ decision to use CCS, drawing on generation differences formulated on the basis of generation theory, with a particular focus on Russian consumers. The factors highlighted as a result of systematization of existing studies have been tested on the data of a quantitative study conducted in the form of an online survey with a sample of 3635 Russian users of CCS. An explanatory factor analysis (EFA) helps the authors construct the framework of factors that influence the decision of three generations of consumers (X, Y, and Z) to use CCS. The analysis of variance between the groups (ANOVA) highlights the generation differences that affect the decision to use the CCS by representatives of three generations. The identified generation features are of both theoretical significance, serving as a basis for further research, and practical value for business, mitigating the risks of introducing new CCS to the market, allowing for the needs of various generations of users.

NEUROPHYSIOLOGICAL EVIDENCE IN IDEA GENERATION: DIFFERENCES BETWEEN DESIGNERS AND ENGINEERS

The paper describes the rigorous implementation of a validated methodological experimental protocol to divergent and convergent thinking tasks occurring in Design by neurophysiological means (EEG and eye-tracking). EEG evidence confirms the findings coherently to the literature. Interesting is the confirmation of such results through eye-tracking ones, and further evidence emerged. In particular, neurophysiological results in idea generation differ between designers and engineers. This study was supported by a multidisciplinary team, both for the neuropsychological and data analysis aspects.