Virus infection mediates the effects of elevated CO2 on plants and vectors.

Atmospheric carbon dioxide (CO2) concentration has increased significantly and is projected to double by 2100. To increase current food production levels, understanding how pests and diseases respond to future climate driven by increasing CO2 is imperative. We investigated the effects of elevated CO2 (eCO2) on the interactions among wheat (cv. Yitpi), Barley yellow dwarf virus and an important pest and virus vector, the bird cherry-oat aphid (Rhopalosiphum padi), by examining aphid life history, feeding behavior and plant physiology and biochemistry. Our results showed for the first time that virus infection can mediate effects of eCO2 on plants and pathogen vectors. Changes in plant N concentration influenced aphid life history and behavior, and N concentration was affected by virus infection under eCO2. We observed a reduction in aphid population size and increased feeding damage on noninfected plants under eCO2 but no changes to population and feeding on virus-infected plants irrespective of CO2 treatment. We expect potentially lower future aphid populations on noninfected plants but no change or increased aphid populations on virus-infected plants therefore subsequent virus spread. Our findings underscore the complexity of interactions between plants, insects and viruses under future climate with implications for plant disease epidemiology and crop production

Selfies, Policies or Votes? Political Party Use of Instagram in the 2015 and 2016 Spanish General Elections

Do parties in Spain use Instagram and for what purpose? What characterizes posts that are effective at engaging the electorate? This article examines the use of Instagram during the Spanish general elections of 2015 and 2016. Content analysis of party publications on Instagram was carried out to test whether parties use the application to broadcast their policy positions, mobilize voters, or to promote their main party candidate. Regression estimation models are then used to explain the varying levels of user engagement with party posts. The findings illustrate that the new challenger parties, Podemos and Ciudadanos, use the social media app in a systematic way that is distinct from the traditional mainstream parties in Spain. Moreover, party newness, attempts at mobilization, and the promotion of the main party candidate are found to be important explanations for party success on Instagram