Exposure to high temperatures is fatal for eggs and suppresses growth in a false widow spider, <em>Steatoda grossa</em>

Global warming is happening currently, along with longer and more frequent and severe heatwaves. Gradual warming and heatwaves might have different effects on animals based on their life stages and sex. Especially for ectotherms, their physiology is largely determined by ambient temperature. In a world where insect biodiversity declines rapidly, the existence of spiders as high-trophic animal taxa received less attention. Therefore, studying spider responses to heat provides valuable insights into population dynamics within the context of global warming. In this study, we exposed a false widow spider (Steatoda grossa) to thermal exposure in each life stage and studied the effects of a simulated heatwave on females and males. Regarding survival, we found out that eggs are most vulnerable to heat, followed by spiderlings and then adults. Body size and physiological responses might be the reason for stage-dependent thermal tolerance. For adults, reproductive performances were negatively af..., , , # Data from: Exposure to high temperatures is fatal for eggs and suppresses growth in a false widow spider, *Steatoda grossa* [https://doi.org/10.5061/dryad.4mw6m90ht](https://doi.org/10.5061/dryad.4mw6m90ht) 2020-2022 Steatoda grossa: the effects of thermal treatments on egg survival, spiderling development and survival, and adult reproductive success. * eggs.csv: The first one to four egg sacs from 30 different mothers were collected from each female soon after laying and placed individually in a petri dish. Egg sacs were randomly assigned to the control temperature (22°C, n = 21), one of the two thermal stress treatments (27 °C, n = 21; and 32°C, n = 19), or the standard experimental heatwave treatment (n = 20). We quantified hatching duration (number of days until hatching), hatching success (proportion of eggs that hatched), and the average body mass of spiderlings per egg sac under each of the temperature conditions (22°C, 27°C, 32°C, and the experimental heatwave). - spiderli..., ,