Indirect effect of earthworms on wheat-aphid interactions

The aboveground and belowground compartments of terrestrial ecosystems, which are generally separated in interaction studies, are nevertheless linked by their dependence on the same plant. Soil organisms can influence interactions between plants and above-ground herbivores by changes in plant growth and chemistry. In the present study, under controlled conditions the direct influence of earthworms and aphids on wheat traits (biomass; C and N content) was investigated. The effect of earthworms on aphid reproduction was also investigated, in order to demonstrate the indirect plant-trait-mediated effects. The results showed a significant effect of both above and below-ground organisms on plant traits. Indeed, wheat biomass and carbon and nitrogen contents were influenced by the presence of earthworms and aphids, suggesting that earthworms can promote aboveground and belowground plant growth by promoting resource acquisition. Interestingly, the nitrogen content was significantly higher in t..., A factorial greenhouse experiment was performed using wheat under four conditions: absence/presence of earthworms, and absence/presence of aphids. A total of 60 pots (4x15 pots, height = 21.8 cm; diameter = 18.7 cm) was filled with soil. The study soil was a Haplic Luvisol and was sampled in an agricultural field. After being air-dried, the soil was sieved at 4 mm. Gauze was attached at the bottom of each pot to prevent earthworms from escaping. On 3 March 2023, five untreated wheat seeds, Triticum aestivum L. (Fructidor variety) were planted. Plants were watered twice a week and kept in a greenhouse with ambient temperature (an average of 12 °C at night and 25 °C by day, for 61 days), humidity, and light. Once the seeds had germinated and reached the early tillering stage, the plants were thinned to two plants per pot. On 4 April 2023, aphids and earthworms were inoculated. Fifteen pots were prepared for each treatment: 15 pots without earthworms nor aphids; 15 pots with aphids but wit..., , # Indirect effect of earthworms on wheat-aphid interactions | Column | Description | | :-------------- | :------------------------------------------------------------------------------------ | | Nb\_Pot | Number of pot | | Mod | Treatments: V: Presence of earthworms; P: Presence of aphids; T: Control (wheat only) | | ID | Pot ID: Treatment + pot number | | Nb\_Ver\_i | Number of earthworms in pot at the beginning of experiment | | Nb\_Ver\_f | Number of earthworms in pot at the end of experiment | | Biom\_Ver\_i | Initial biomass of earthworms (g) | | Biom\_Ver\_f | Final biomass of earthworms (g) ...