Fig. 1: Microclimate heterogeneity, FSBT of S. avenae and their effects on aphid survival and population growth under EHT.
From: Behavioural plasticity of a pest species may aggravate global wheat yield loss under climate change
Temperatures of different microhabitats (air, leaf, and soil surface) during daytime (08:00–16:00) and probability of aphids (1st, 2nd, 3rd, 4th nymphal instars and adults) residing on the host plant under the conditions (a) with and (b) without EHT. For each development stage, the data (means & SEM) for tested aphids (n = 30) placed individually in different experimental arenas were observed at each time interval. Results of clip cage experiment: c effects of fine-scale behavioural thermoregulation (FSBT) and extreme high temperature (EHT) combination treatments on temperature ranges experienced by aphids during daytime, and d the resulting intrinsic rate of increase (rm) and survival of the aphids. EHT(+)FSBT(-) = with EHT but without FSBT; EHT(+)FSBT(+) = with both EHT and FSBT; EHT(−)FSBT(−) = without both EHT and FSBT; EHT(−)FSBT(+) = without EHT but with FSBT. Kaplan–Meier survival curves were compared using a log-rank test (χ²=68.7917, df = 3, p < 0.0001), with Holm-Bonferroni correction for multiple comparisons. Results of soil moisture experiment: e effects of FSBT and EHT combination treatments on temperature ranges experienced by aphids during daytime, and f the resulting aphid abundances. The results deriving from linear models are EHT(+)FSBT(-): y = 2.64–0.16x, F(1,80) = 395.4172, R2 = 0.8352, p < 0.0001; EHT(+)FSBT(+): y = 3.00 + 0.04x, F(1,80) = 21.1795, R2 = 0.2135, p < 0.0001; EHT(−)FSBT(−): y = 2.89 + 0.22x, F(1,80) = 1080.3322, R2 = 0.9327, p < 0.0001; EHT(-)FSBT(+): y = 2.84 + 0.21x, F(1,80) = 998.3312, R2 = 0.9275, p < 0.0001. Model performance was evaluated using the coefficient of determination (R²), and statistical significance was assessed via two-sided F-tests (P-values reported). Symbols indicate observations at each time interval, while lines represent the fitted linear models. Differences among treatments shown in Table S3. Temperature data shown (c, e) only for one EHT event. Tested aphid survival (circles) and non-linear survival models (curves) under the conditions with and without (by using clip cages) FSBT at different simulated daily maximum temperatures (DTmax). g Experimental temperature fluctuations experienced by aphids during daytime EHTs varying in intensity (DTmax). h Fitting Gompertz sigmoidal model (f = a*exp(-exp(-(x-x0)/b))) curves based on a non-linear regression analysis for describing the changes of aphid survival with DTmax with and without FSBT. The model with FSBT is Survival = 1.01*exp(-exp(-(DTmax-43.24)/(−1.62))) (R2 = 0.9615, p < 0.0001) and model without FSBT is Survival = 0.99*exp(-exp(-(DTmax-40.48)/(−1.03))) (R2 = 0.9732, p < 0.0001). Model performance was evaluated using the coefficient of determination (R²), and statistical significance was assessed via two-sided F-tests (P-values reported). Source data are provided as a Source Data file.
