Arthropod assemblage related to volatile cues in flowering wheat: interaction between aphid herbivory and soil conditions as induction factors

LENARDIS, A.; SZPEINER A; GHERSA CM

ENVIRONMENTAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2014 vol. 43 p. 448 - 457

0046-225X

Volatile cues released by plants play an important role in plant-insect interactions and are influenced by pests or soil conditions affecting plant metabolism. Field microcosm experiments were used to characterize arthropod spontaneous assemblies in homogenous unstressed wheat patches exposed to volatile cues coming from wheat plants with different levels of stress. The design was a factorial BCRD with 3 replications.  Source wheat pots combined two stress factors: (1) soil degradation level: high (D) and low (ND) and (2) aphid herbivory: with (A) and without (B). Eighteen experimental units consisted of source stressed wheat pots, connected by tubes conducting the volatile cues to sink wheat patches. These patches were located at the end of the tubes placed in a flowering wheat field. Arthropod assemblies on wheat sinks were different between years and they were associated to the source cues. Soil condition was the main discriminating factor among arthropods when a clear contrast between high and low soil degradation was observed, while aphid herbivory was the main discriminating factor when soil condition effects were absent.  Main soil properties related with arthropods assembly were Mg and K in the first year and CEC, Nt, pH in the second year of experiment. According to this study, spontaneous arthropod distributions in the homogeneous unstressed wheat patch responded to the volatile cues coming from wheat sources growing in particular soil conditions. It is possible to suggest that soil-plant-herbivore interactions change wheat cues and this phenomenon produces significant differences in neighboring arthropod community structure