Flu pandemics may be more likely in spring, early summer
You might assume that the risk of a new flu pandemic would be highest during the height of the flu season in winter, when viruses are more abundant and most likely to spread. However, all six flu pandemics that have occurred since 1889 emerged in the spring and summer. Why might this be?
Spencer Fox of the University of Texas and his colleagues developed a computational model that mimics viral spread during flu season, incorporating real-world data on flu transmission from the 2008-09 flu season. They used their model to run thousands of simulations in which new pandemic viruses emerged at different points throughout the flu season. These showed that cross-virus immunity delayed wintertime spread of new strains and led to spring and summer pandemics, which the authors suggest could help public health agencies detect and respond to new viral threats.
Research Article: Fox SJ, Miller JC, Meyers LA (2017) Seasonality in risk of pandemic influenza emergence. PLoS Comput Biol 13(10): e1005749. https://doi.org/10.1371/journal.pcbi.1005749
Image Credit: Spencer J. Fox
Many female jumping spiders only mate once in their lifetimes
Females of many insect and spider species can store sperm, which can then be displaced by or diluted with sperm from subsequent matings. To reduce this sperm competition, females that have already mated become unreceptive and aggressive to males, and there is more to learn about the long-term impact of mating-induced sexual inhibition.
In a new study, Vivian Mendez and colleagues from Macquarie University in Australia studied the mating behaviour of 89 young female Servaea incana jumping spiders that were caught in the wild in Australia. Each female was paired with a different male daily for the first 10 days of her adult life, and every 10 days thereafter for the rest of her life. The researchers found that after the first mating, the female jumping spiders would be unreceptive toward subsequent males, and this effect often persisted for their entire lifetime. These results suggest that female jumping spiders may be able to store and use sperm from their first mating for the rest of their lives.
Research Article: Mendez V, McGinley RH, Taylor PW (2017) Mating-induced sexual inhibition in the jumping spider Servaea incana (Araneae: Salticidae): A fast-acting and long-lasting effect. PLoS ONE 12(10): e0184940. https://doi.org/10.1371/journal.pone.0184940