Sexual selection theory predicts that the different selection pressures on males and females result in sexual conflict. However, in some instances males and females share a common interest which could lead to sexual cooperation. In the pierid butterfly Pieris napi the male and the recently mated female share a common interest in reducing female harassment by other males soon after mating. Here we show that P. napi males transfer an anti-aphrodisiac to the female at mating, methyl-salicylate (MeS), which is a volatile substance which mated females emit when courted and which makes males quickly abandon them. A 13C-labelling experiment demonstrated that only males synthesize MeS. The effect of this antiaphrodisiac is so strong that most males will refrain from mating with virgin females to whom MeS has been artificially applied. In P. napi, males also transfer nutrients to females at mating. This increases female fecundity and longevity and so females benefit from remating. Hence, sexual cooperation gradually turns to conflict. Future research is required to reveal which sex controls the gradual decrease in the MeS titre which is necessary for allowing mated females to regain attractiveness and remate.

Increasing scholarly attention is being paid to urban encounters with ‘difference’. Much of this work to‐date has focused on incidental encounters in various spatial settings from the market to the café. Here, a number of commentators have observed that fleeting, unintended encounters, where diverse people rub along together as a consequence of accidental proximity, do not necessarily produce ‘meaningful contact’. That is contact which breaks down prejudices and translates beyond the moment to produce a more general respect for others. This paper contributes to these debates by focusing instead on purposeful organised activities (‘The Project’) to bring two different groups together intentionally who would not normally have the opportunity for sustained engagement through a case study of an interfaith (Muslim and Jewish) youth cricket project in a large UK city. Here, we use the concept of the ‘contact zone’ to evaluate the effectiveness of this project. The findings highlight three critical processes which contribute to generating meaningful contact. First, it is important to establish space where participants from different groups can safely explore their differences together. Second, it is necessary to create space to establish shared interests: here through the game of cricket. Both are factors which require significant resourcing, in particular to enable a professional facilitator to manage what can be, or become, conflictual encounters and the expression of potentially negative emotions. Third, banal sociality also matters. It was time spent ‘hanging out’ alongside, instead of in, the purposeful activities when the participants identified their own natural affinities and found particular shared identity positions which contributed to destabilising the significance of differences beyond those The Project sought to address. These findings have clear relevance for future policy initiatives to develop interfaith relations.

SUMMARY In butterflies female mate choice is influenced by both visual and olfactory cues, the latter of which are important at close range. Males of the green-veined butterfly, Pieris napi, are known to release citral(mixture of geranial and neral, 1:1), but its role(s) and conditions of release are not known. Here, we show that male P. napi release citral when interacting with conspecific males, conspecific females, heterospecific males and also when alone. The amount of citral released correlated strongly with male flight activity, which explained more than 70% of the variation. This suggests that males do not exercise control over turning release on or off, but rather that citral is emitted as a passive physical process during flight. Electroantennogram experiments showed that female antennal response was ten times more sensitive to citral than male response. Females expressed acceptance behavior when exposed to models made with freshly excised male wings or those treated with citral following chemical extraction, but not to ones with extracted wings only. Hence, these behavioral and electrophysiological tests provide strong evidence that citral is a signal from the male directed to the female during courtship, and that it functions as a male sex pheromone.

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