An attractive male trait and aggressiveness are negatively correlated in wild field crickets, but uncorrelated in lab-reared crickets

It is generally thought that attractive male traits are positively correlated with dominance (aggressiveness). However, growing evidence suggests that this is not necessarily the case. We investigated whether calling song, a male mating display used by females to evaluate potential mates in a field cricket (Gryllus integer), is correlated with aggressiveness. In this species, females prefer males with longer durations of singing time. We measured singing time by measuring song over three continuous days using a custom-designed audio-monitor and assessed aggressiveness by pairing males in agonistic interactions. Our results showed that for males caught in the field, the percentage of time spent singing was negatively correlated with aggressiveness. However, in males that were raised in the laboratory, the percentage of time spent singing was not correlated with aggressiveness. Since calling duration is an attractive male trait in these crickets, our data show that the attractiveness of males can be either negatively related to aggressiveness (field) or unrelated to aggressiveness (lab). Neither of these results fit the traditional view that preferred male mating cues should be positively correlated with dominance (aggressiveness). These results also suggest that measurements of aggressiveness made in the lab do not necessarily correspond with aggressiveness in the field.     

The injury problem among older adults: mortality, morbidity and costs

The Journal of Safety Research has partnered with the National Center for Injury Prevention and Control at the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, USA, to briefly report on some of the latest findings in the research community. This report is the seventh in a series of CDC articles.     

Predicted taxonomic patterns in pheromone production by longhorned beetles

Males of five species of three tribes in the longhorned beetle subfamily Cerambycinae produce volatile pheromones that share a structural motif (hydroxyl or carbonyl groups at carbons two and three in straight-chains of six, eight, or ten carbons). Pheromone gland pores are present on the prothoraces of males, but are absent in females, suggesting that male-specific gland pores could provide a convenient morphological indication that a species uses volatile pheromones. In this article, we assess the taxonomic distribution of gland pores within the Cerambycinae by examining males and females of 65 species in 24 tribes using scanning electron microscopy. Gland pores were present in males and absent in females of 49 species, but absent in both sexes of the remaining 16 species. Pores were confined to indentations in the cuticle. Among the species that had male-specific gland pores were four species already known to produce volatile compounds consistent with the structural motif. These findings support the initial assumption that gland pores are associated with the production of pheromones by males. There were apparently no taxonomic patterns in the presence of gland pores. These findings suggest that volatile pheromones play an important role in reproduction for many species of the Cerambycinae, and that the trait is evolutionarily labile.     

Reduced adsorption of ametryn in clay, humic acid, and soil by interaction with ferric ion under Fenton treatment conditions

Previous work in our laboratory indicated a weak interaction between ferric ion and several triazine/triazinone herbicides during a Fenton treatment process, and the intensity of the interaction was calculated. To further support the existence of this weak interaction, the adsorption of ametryn, a triazine herbicide, was investigated in kaolinite clay, humic acid, and soil under pseudo-Fenton conditions. At a low addition rate of ferric ion, the adsorption of ametryn in clay, humic acid, and soil was enhanced due to the decreased pH resulting from the hydrolysis of ferric ion. But the pH effect was totally neutralized and the adsorption of ametryn was significantly reduced by further addition of ferric ion, demonstrating the existence of the weak interaction between ametryn and ferric acid. Further study showed that the adsorption-reduction effect of ferric ion existed not only with ametryn but also with several other triazine/triazinone herbicides. This weak interaction may accelerate the desorption process during the remediation of triazine/triazinone herbicide-contaminated soil using a Fenton/Fenton-like treatment, but it may also impede the degradation of these herbicides.     

Contesting neoliberal knowledge politics in restoration governance: the restorationist’s dilemma

ABSTRACT

The success of ecological restoration efforts is tightly coupled with the effectiveness of many U.S. environmental policies. Yet scholars have raised questions about the ability of restoration to produce intended results. We use a case study of tidal wetland restoration planning in Oregon to examine how neoliberal environmental governance exercises influence through a set of knowledge politics that produces subpar outcomes. We present three main findings: (1) restoration policies produce a restoration economy based on a conception of wetland as commodity (2) practitioners in this restoration economy exhibit competitive behavior resulting in a piecemeal rather than a landscape approach to restoration; and (3) limited monitoring prevents changes to existing policies. Practitioners offer insight into the challenge of treating wetlands as a commodity and call for more monitoring to challenge the assumptions of hegemonic knowledge practices that reinforce a neoliberal environmental governance regime. The divergent ideas of reflexive practitioners, though not yet manifest as action, show where changes to restoration governance might be possible.