Early life starvation has stronger intra-generational than transgenerational effects on key life-history traits and consumption measures in a sawfly

Abstract

Resource availability during development shapes not only adult phenotype but also the phenotype of subsequent offspring. When resources are absent and periods of starvation occur in early life, such developmental stress often influences key life-history traits in a way that benefits individuals and their offspring when facing further bouts of starvation. Here we investigated the impacts of different starvation regimes during larval development on life-history traits and measures of consumption in the turnip sawfly, Athalia rosae (Hymenoptera: Tenthredinidae). We then assessed whether offspring of starved and non-starved parents differed in their own life-history if reared in conditions that either matched that of their parents or were a mismatch. Early life starvation effects were more pronounced within than across generations in A. rosae, with negative impacts on adult body mass and increases in developmental time, but no effects on adult longevity in either generation. We found some evidence of higher growth rates in larvae having experienced starvation, although this did not ameliorate the overall negative effect of larval starvation on adult size. However, further work is necessary to disentangle the effects of larval size and instar from those of starvation treatment. Finally, we found weak evidence for transgenerational effects on larval growth, with intra-generational larval starvation experience being more decisive for life-history traits. Our study demonstrates that intra-generational effects of starvation are stronger than transgenerational effects on life-history traits and consumption measures in A. rosae.

Fighting over defence chemicals disrupts mating behaviour

“…fighting or aggressive nibbling) would be less frequent than in the control (♀C-♂C-) and that the reverse would occur when females did not have clerodanoids but males did (♀C-♂C+). In addition, we tested the role of body mass in determining the outcome of the asymmetrical interactions, through its effect on RHP, by using females that were starved during larval development [(S)♀C+♂C-], which is known to lower adult mass in A. rosae [40]. We predicted that lower female body mass would result in an increase in fighting and a decrease in mating behaviour in comparison to the control.…”

Intergenerational Effects of Early Life Starvation on Life-History, Consumption, and Transcriptome of a Holometabolous Insect

“…Consumption assays revealed that starved larvae had a marginally higher growth rate (RGR) but a lower consumption efficiency (ECI) than non-starved larvae, irrespective of their parental starvation treatment. Since we conducted the consumption assays for all larvae at the same developmental stage, we were able to disentangle the effect of starvation from effects due to differences in ontogeny (Nicieza and Álvarez 2009), in contrast to earlier studies on this sawfly (Paul et al 2019). Offspring that experienced starvation exhibited a steeper RGR than non- starved larvae, suggesting compensatory growth (Hector and Nakagawa 2012).…”

“…However, patterns may differ depending on the developmental stage in which an individual is facing starvation, which needs to be further explored in A. rosae. Since we conducted the consumption assays for all larvae at the same developmental stage, we were able to disentangle the effect of starvation from effects due to differences in ontogeny (Nicieza and Álvarez 2009), in contrast to earlier studies on this sawfly (Paul et al 2019).…”

“…Periods of starvation are commonly encountered by insects in the wild (Jiang et al 2019) and, when experienced early in life, often have long-lasting effects on an individual’s phenotype, affecting life-history, consumption, and behavior (Miyatake 2001; Wang et al 2016; McCue et al 2017). Intergenerational effects of starvation events on offspring developmental trajectories have been found to differ depending on the exact starvation regime, sex, and traits that are considered (Saastamoinen et al 2013; McCue et al 2017; Paul et al 2019). Moreover, to fully elucidate the adaptive nature of intergenerational effects, studies should encompass different phases in development during the parental life cycle and how such experience affects individual offspring phenotypes (English and Barreaux 2020).…”

“…One important environmental factor that can rapidly change during an organism's lifetime and across generations is food availability. Periods of starvation are commonly encountered by insects in the wild (Jiang et al 2019) and, when experienced early in life, often have long-lasting consequences on an individual's phenotype (Miyatake 2001;Wang et al 2016;McCue et al 2017) and the phenotype of the offspring (Saastamoinen et al 2013;McCue et al 2017;Paul et al 2019). However, it is also becoming increasingly apparent that to fully elucidate the adaptive nature of intergenerational effects, studies should encompass different phases in development of the parental life cycle and how such life stage-specific experience affects offspring phenotype (English and Barreaux 2020).…”