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Climate change will cause drastic fluctuations in agricultural ecosystems, which in turn may affect global food security. We used ecological niche modeling to predict the potential distribution for four cereal aphids (i.e., Sitobion avenae, Rhopalosiphum padi, Schizaphis graminum, and Diurphis noxia) and their three natural enemy insects (i.e., Harmonia axyridis, Episyrphus balteatus, and Aphidius gifuensis) in China's farmland under current and projected climate scenarios. Due to climate change, the suitable areas of D. noxia, E. balteatus, and A. gifuensis will shrink, while those of other target insects will expand. Focusing on the scenario of high greenhouse gas emissions for the period of 2081–2100, all our target insects will move toward higher latitudes, and all of them will move toward higher altitudes except D. noxia. The niche overlap between three aphids (i.e., S. avenae, R. padi, and S. graminum) tends to increase with climate change in most regions. The aphid suppression capacity of ladybug H. axyridis will increase with climate change, while it will weaken for hoverfly E. balteatus and parasitoid A. gifuensis, showing that climate change can favor generalist over specialist enemies. We developed a new mathematical model for projecting wheat yield shifts due to climate change, and found a projected increase in net yield loss by aphids by the end of the century. Our results illustrate the food security imperative of clarifying the impact of climate change on cereal-producing systems, and provide insightful information for design of pest management strategies in the context of global climate change. [ABSTRACT FROM AUTHOR]

Background The use of non-standard motorcycle helmets has the potential to undermine multinational efforts aimed at reducing the burden of road traffic injuries associated with motorcycle crashes. However, little is known about the prevalence or factors associated with their use. Methods Collaborating institutions in nine low- and middle-income countries undertook cross-sectional surveys, markets surveys, and reviewed legislation and enforcement practices around non-standard helmets. Findings 5563 helmet-wearing motorcyclists were observed; 54% of the helmets did not appear to have a marker/sticker indicating that the helmet met required standards and interviewers judged that 49% of the helmets were likely to be non-standard helmets. 5088 (91%) of the motorcyclists agreed to be interviewed; those who had spent less than US$10 on their helmet were found to be at the greatest risk of wearing a non-standard helmet. Data were collected across 126 different retail outlets; across all countries, regardless of outlet type, standard helmets were generally 2-3 times more expensive than non-standard helmets. While seven of the nine countries had legislation prohibiting the use of non-standard helmets, only four had legislation prohibiting their manufacture or sale and only three had legislation prohibiting their import. Enforcement of any legislation appeared to be minimal. Interpretation Our findings suggest that the widespread use of non-standard helmets in low- and middle-income countries may limit the potential gains of helmet use programmes. Strategies aimed at reducing the costs of standard helmets, combined with both legislation and enforcement, will be required to maximise the effects of existing campaigns. [ABSTRACT FROM AUTHOR]