Increased ladybird predation and metabolism do not counterbalance increased field aphid population growth under experimental warming

Climate change may have diverse and complex impacts on species interactions, destabilizing food webs and ecosystem services. The effects of warming on the top-down biological control of crop pests have been considerably less studied than bottom-up effects through crop physiological changes.
We studied the effect of a 2 °C warming in the laboratory and in wheat fields on the predation and metabolism of Harmonia axyridis on wheat aphids using molecular gut content analysis. We also measured the effects of warming on the predation rate and functional response of H. axyridis on each aphid species in the laboratory, as well as on DNA degradation rate.
Field densities of Sitobion avenae and Rhopalosiphum padi, the two most abundant wheat aphid species, were increased by 2 and 2.5 times, respectively, under experimental warming, but densities of H. axyridis were not. Field predation rate of H. axyridis on these two aphids was found to be about 25% lower under elevated temperature. This could ..., Experimental design
Field experiments were conducted in Langfang, Hebei Province (Langfang Research Station, Institute of Plant Protection, Chinese Academy of Agricultural Sciences; 39°30’N, 116°36’E) and in Yuanyang, Henan Province (Modern Agricultural Science and Technology, Henan Academy of Agricultural Sciences; 34°55’N, 114°15’E). The climate at both stations is continental warm temperate with a monsoon season from April to September and mean annual precipitations of 550 mm; the mean annual temperature is 12.3 °C in Langfang and 14.4 °C in Yuanyang (http://data.cma.cn/). In each station, one field (23 × 16m) was selected and grown with wheat Triticum aestivum L. variety Hengguan 35, which is adapted to dry conditions. In each field, twelve plots of 2 m × 2 m were selected and randomly assigned to control (ambient temperature; six plots) or to treatment (warming; six plots). Plots were separated by a buffer of at least 5 m of bare ground. MSR-2420 infrared heaters (Kalglo Electronic..., , # Increased ladybird predation and metabolism do not counterbalance increased field aphid population growth under experimental warming

**2024-01-30_Population_dynamics.csv**

Population dynamics data (M&M section 2.2)

**2024-01-30_Standard_calibration_curves.csv**

Standard calibration curves data (M&M section 2.3, 2.4, 2.5)

**2024-01-30_Field_GutContent.csv**

DNA gut content of field specimens of ladybirds (M&M section 2.5)

**2024-01-30_Functional_response_lab.csv**

Functional response data (M&M section 2.6)

**2024-02-01_Lab_predation_choice_expe.csv**

Laboratory predation choice experiment data (M&M section 2.7)

**2024-01-30_Gut_DNA_degradation.csv**

Data on digestion of wheat aphid DNA in ladybirds gut in the laboratory (M&M section 2.7)

## Description of the data and file structure

**2024-01-30_Population_dynamics.csv**

* Treatment: warming treatment (A=ambient 19°C; E=elevated 21°C)
* Plot: Plot ID
* Site: Site (Langfang versus Yuanyuan ...