Climate Change Impact on Neotropical Social Wasps

Establishing a direct link between climate change and fluctuations in animal populations through long-term monitoring is difficult given the paucity of baseline data. We hypothesized that social wasps are sensitive to climatic variations, and thus studied the impact of ENSO events on social wasp populations in French Guiana. We noted that during the 2000 La Niña year there was a 77.1% decrease in their nest abundance along ca. 5 km of forest edges, and that 70.5% of the species were no longer present. Two simultaneous 13-year surveys (1997–2009) confirmed the decrease in social wasps during La Niña years (2000 and 2006), while an increase occurred during the 2009 El Niño year. A 30-year weather survey showed that these phenomena corresponded to particularly high levels of rainfall, and that temperature, humidity and global solar radiation were correlated with rainfall. Using the Self-Organizing Map algorithm, we show that heavy rainfall during an entire rainy season has a negative impact on social wasps. Strong contrasts in rainfall between the dry season and the short rainy season exacerbate this effect. Social wasp populations never recovered to their pre-2000 levels. This is probably because these conditions occurred over four years; heavy rainfall during the major rainy seasons during four other years also had a detrimental effect. On the contrary, low levels of rainfall during the major rainy season in 2009 spurred an increase in social wasp populations. We conclude that recent climatic changes have likely resulted in fewer social wasp colonies because they have lowered the wasps' resistance to parasitoids and pathogens. These results imply that Neotropical social wasps can be regarded as bio-indicators because they highlight the impact of climatic changes not yet perceptible in plants and other animals

Rethinking capital mobility, re‐regulating financial markets

The globalisation hypothesis has altered many of the common-sense ‘truths’ around which the social world is organised.* In particular, globalisation is thought to restrict the parameters of the politically and economically possible. Indeed, the notion of constrained choice is so pronounced that we are increasingly confronted with the image of globalisation’s ‘logic of no alternative’; an image which is predicated on the assumption of perfect capital mobility. Capital is considered to be sufficiently rational to take advantage of enhanced exit options from the national economy in circumstances in which its interests are served by moving off-shore. Moreover, global markets are also assumed to have exploited contemporary technological developments to such an extent that they now clear instantaneously; consequently, allowing capital to further its interests wherever in the world new profit opportunities arise. Thus, we are presented with the fundamental ‘reality’ of globalisation as currently narrated throughout much of the west: unless the market can be allowed to restore a competitive global equilibrium, capital will exit high-wage, high-cost western economies and re-locate in lower-wage, lower-cost, newly industrialising economies. Under the auspices of ever more hostile wage competition from the newly industrialising economies, globalisation is commonly presumed to act as a trigger for an ‘inevitable’ job displacement effect as capital deserts the advanced industrialised economies

Selected Writing of John Stuart Mill

432 hal.;18 c