Short communication. Mutual pheromone antagonism in two sympatric corn borers, Sesamia nonagrioides and Ostrinia nubilalis, under field conditions

In previous studies, we demonstrated cross-antagonism in pheromone perception between pheromone componentsof the two corn (Zea mays L.) borers Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae) and Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) in the laboratory and in the field. The two pheromone components identified as responsible for this cross-antagonism were Z 11-16:Ald, a minor component of S. nonagrioides pheromone, and Z 11-14:Ac, the main component of the pheromone of the Z-strain of O. nubilalis, which inhibited the response of O. nubilalis and S. nonagrioides, respectively. Here, we study this antagonism phenomenon in the field by air permeation of maize plots with each of the two components separately and measurement of mating in caged couples of the two corn borers on treated and untreated plots during three years. A significant reduction in mating rates was observed on the permeated plots: 7% for S. nonagrioides and 12% for O. nubilalis. When dispenser charges (200 ng) were increased by 50% and 75% in the third year, no decrease in mating rates was recorded at either of the increased concentrations. On the other hand, the use of large cages resulted in an increase of 8% to 12% in the percentage of unmated females in each of the two corn borers suggesting that at more realistic field corn borer densities, 0,1 couples/plant instead of the 2 couples/plant used in this experiment, cross-antagonism in the two corn borers could be higher than that recorded in small cages.

Short communication. Potential to mitigate anthropogenic CO2 emissions by tillage reduction in dryland soils of Spain

Spain is one of the countries with the highest greenhouse gas (GHG) emissions within the EU-27. Consequently, mitigation strategies need to be reported and quantified to accomplish the goals and requirements of the Kyoto Protocol. In this study, a first estimation of the carbon (C) mitigation potential of tillage reduction in Mediterranean rainfed Spain is presented. Results from eight studies carried out in Spain under rainfed agriculture to investigate the effects of no-tillage (NT) and reduced tillage (RT) compared with conventional tillage (CT) on soil organic carbon (SOC) were used. For current land surface under conservation tillage, NT and RT are sequestering 0.14 and 0.08 Tg C yr-1, respectively. Those rates represent 1.1% and 0.6% of the total CO2 emissions generated from agricultural activities in Spain during 2006. Alternatively, in a hypothetical scenario where all the arable dryland was under either NT or RT management, SOC sequestration would be 2.18 and 0.72 Tg C yr-1 representing 17.4% and 5.8% of the total 2006 CO2 equivalent emissions generated from the agricultural sector in Spain. This is a significant estimate that would help to achieve GHG emissions targets for the current commitment period of the Kyoto Protocol.

Cognitive Predictors and Risk Factors of PTSD Following Stillbirth: A Short-Term Longitudinal Study.

This short-term longitudinal study investigated cognitive predictors and risk factors of posttraumatic stress disorder (PTSD) in mothers following stillbirth. After a stillbirth at ≥ 24 weeks gestational age, 65 women completed structured clinical interviews and questionnaires assessing PTSD symptoms, cognitive predictors (appraisals, dysfunctional strategies), and risk factors (perceived social support, trauma history, obstetric history) at 3 and 6 months. PTSD symptoms decreased between 3 and 6 months (Cohen's d ranged .34-.52). Regression analyses also revealed a specific positive relationship between Rumination and concurrent frequency of PTSD symptoms (β = .45). Negative Self-View and Negative World-View related positively and Self-Blame related negatively to concurrent number of PTSD symptoms (β = .48, .44, -.45, respectively). Suppression and Distraction predicted a decrease and Numbing predicted an increase in time-lagged number of PTSD symptoms (β = -.33, -.28, .30, respectively). Risk factors for PTSD symptoms were younger age (β = -.25), lower income (β = -.29), fewer previous pregnancies (β = -.31), and poorer perceived social support (β = -.26). Interventions addressing negative appraisals, dysfunctional strategies, and social support are recommended for mothers with PTSD following stillbirth. Knowledge of cognitive predictors and risk factors of PTSD may inform the development of a screening instrument.