Parasitoid females may adjust offspring sex allocation according to the number and quality of hosts available. Because in solitary species only one offspring survives per host, already parasitized hosts are of low quality and generally rejected. Superparasitism (i.e., sequential oviposition by the same or different females) results in aggressive interactions and competition for nutritional resources among larvae. We examined variations in the offspring sex ratio of Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), a solitary ectoparasitoid developing as a hyperparasitoid on the prepupae and pupae of primary aphid parasitoids inside mummified aphids. Mated females produced a female-biased sex ratio of 0.433 (proportion of sons) when caged singly and provided with 12 mummies for 2 h; they parasitized an average of four mummies/h and rarely superparasitized. Superparasitism increased when two females were caged together and provided with 12 mummies, from 1.18 to 1.24 and 1.38 eggs/host parasitized in 1, 2 and 3 h, respectively. The offspring sex ratio became increasingly more female-biased with increase in superparasitism; however, sex ratio variations were not correlated with cohort size. One mated and one unmated female provided with 12 mummies and caged together for 1 h produced a mean cohort sex ratio of 0.645, which differed from the one predicted (0.717) by an algebraic model incorporating the assumptions that both females contribute equal numbers of offspring and that the mated female does not change her offspring-sex allocation strategy. The observed shift in the cohort sex ratio to an increased female-bias indicates that mated females of D. carpenteri change their behaviour when encountering parasitized mummies or a conspecific competitor in the same patch. By depositing fertilized rather than unfertilized eggs, a female can increase the proportion of her daughters among parasitoids competing for a diminishing host supply., Manfred Mackauer, Andrew Chow., and Obsahuje bibliografii
Building on historical narrative and social-theoretical analysis, Fraser explores the place of second-wave feminism in relation to three specific moments in the history of capitalism. The first point refers to the movement’s beginnings in the context of ‘state-organized capitalism’. The second point refers to the process of feminism’s evolution in the dramatically changed social context of rising neoliberalism. And the third point refers to a possible reorientation of feminism in the present context of capitalist crisis and US political realignment, which for her could mark the beginning of a shift from neoliberalism to a new form of social organization. Orienting her analysis around four key points of feminist critique-androcentrism, economism, étatism and Westphalianism-Fraser charts a fascinating journey of second-wave feminism since the 1960s to identify a “dangerous liaison” second-wave feminism developed with capitalism. She concludes that in order to reclaim second-wave feminism as a robust critique conjoining both claims for recognition and redistribution- which were unlinked during the period of rising neoliberalism-eminism needs to become more historically self-aware., Nancy Fraser ; přeložila Marcela Linková., and Přeloženo z : New Left Review 56/2009
The article introduces feminist political economy as an analytical tool or interpretative frame for exploring current economic crisis. In the beginning of the article, the authors focus on the wider context of feminist theories and approaches to capitalism within their development. The point is to show that contemporary feminist critiques of global capitalism tie in with the earlier tradition of feminist thought. In the next part, the authors introduce the theoretical grounds and basic theses of feminist political economy through the work of V. Spike Peterson and J. K. Gibson-Graham. The last part of the article focuses on specific issues linked to the current crisis of global capitalism and on the questions raised by this approach. The main questions are: how can we describe the crisis and what solutions can we search for? Is it a crisis of the hegemonic capitalist mode of production, a crisis of the capitalocentrist order, or just a crisis of certain institutions? Is the current economic crisis only a negative phenomenon, or does it open the way to establishing alternative paradigms to that of the global hegemony of capitalism?, Veronika Šprincová, Miroslav Jašurek., Obsahuje bibliografii, and Anglické resumé