Predictors of individual performance and evolutionary potential of life-history traits in a hematophagous ectoparasite

Gerardo Fracasso, Dieter Heylen, Stefan Van Dongen, Joris Elst, Erik Matthysen

    Research output: Contribution to journalA1: Web of Science-article

    Abstract

    Little is known about the intraspecific variation of parasite life-history traits and how this variation may affect parasite fitness and evolution. We investigated how life-history traits predict success of individual tree-hole ticks Ixodes arboricola and estimated their evolutionary potential, as well as genetic correlations within stages and phenotypic correlations within and across stages. Ticks were followed individually over two generations while allowed to feed on great tits Parus major. After accounting for host and tick maternal effects, we found that short feeding times and high engorgement weights strongly increased molting success. Molting time was also positively correlated with feeding success in adults. In larvae and nymphs, we found negative phenotypic correlations between engorgement weight and both feeding and molting time, the latter supported by a negative genetic correlation. We found sex-related differences in feeding time (longer in male nymphs) and molting time (longer in male larvae but shorter in male nymphs). Also, time since the last feeding event (set experimentally) reduced larval and nymphal fitness, whereas it increased adult female fitness. Furthermore, we found significant heritability and evolvability, that is, the potential to respond to selection, for engorgement weight and molting time across all stages but no significant heritability for feeding time. Our findings suggest that variation in tick fitness is shaped by consistent individual differences in tick quality, for which engorgement weight is a good proxy, rather than by life-history trade-offs.

    Original languageEnglish
    JournalEvolution
    Volume76
    Issue number4
    Pages (from-to)799-816
    Number of pages18
    ISSN1558-5646
    DOIs
    Publication statusPublished - 2022

    Keywords

    • Evolutionary potential
    • heritability
    • host-parasite interactions
    • Ixodes arboricola
    • parasite success
    • Parus major
    • Tree-hole tick
    • HOST-SPECIFICITY
    • IXODIDAE TICKS
    • SURVIVAL

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