Tuesday, March 25, 2014

Olive bioeconomics under climate warming

Inability to determine reliably the direction and magnitude of change in natural and agro-ecosystems due to climate change poses considerable challenge to their management. Olive is an ancient ubiquitous crop having considerable ecological and socioeconomic importance in the Mediterranean Basin. We assess the ecological and economic impact of projected 1.8 °C climate warming on olive and its obligate pest, the olive fly. This level of climate warming will have varying impact on olive yield and fly infestation levels across the Mediterranean Basin, and result in economic winners and losers. The analysis predicts areas of decreased profitability that will increase the risk of abandonment of small farms in marginal areas critical to soil and biodiversity conservation and to fire risk reduction.

Ponti L., Gutierrez A.P., Ruti P.M., Dell’Aquila A., 2014. Fine scale ecological and economic assessment of climate change on olive in the Mediterranean Basin reveals winners and losers. Proceedings of the National Academy of Sciences, USA, http://dx.doi.org/10.1073/pnas.1314437111

Wednesday, March 12, 2014

Ultra-low, cryptic tropical fruit fly populations

A comment appeared in Proceedings B reviews a study by Papadopoulos, Plant, and Carey (2013; "From trickle to flood: the large-scale, cryptic invasion of California by tropical fruit flies." Proc. R. Soc. B: Biol. Sci. 280: http://dx.doi.org/10.1098/rspb.2013.1466) and suggests an alternative approach that addresses the biology of invasive species. In summary, inference of establishment of fruit flies based on recurrence data as performed by Papadopoulos et al. (2013) is neither explanatory nor provides confirmation of establishment in California. By contrast, physiologically based demographic models for medfly and olive fly accurately predict the potential distribution of the two fruit flies in California and elsewhere, and provide explanation for species phenology and dynamics that is critical for risk assessment and policy development for these and other invasive species under current climate and climate change scenarios.

Gutierrez A.P., Ponti L., Gilioli G., 2014. Comments on the concept of ultra-low, cryptic tropical fruit fly populations. Proceedings of the Royal Society B: Biological Sciences, 281, http://dx.doi.org/10.1098/rspb.2013.2825


Tuesday, February 11, 2014

The new world screwworm: distribution and eradication

The new world screwworm Cochliomyia hominivorax (Coquerel) was eradicated in North America, Libya and other locations using the sterile insect technique (SIT). To examine the role of weather in its eradication, a physiologically-based demographic model (PBDM) was developed and used to characterize its range of year-round persistence. Winter temperature and rainfall are shown to have a strong influence on screwworm outbreaks and in facilitating eradication in North America and Libya. Prospective analysis for the Mediterranean Basin suggests eastern areas are most favorable for screwworm establishment (e.g., the Nile River area of Egypt). The SIT eradication programme and its possible extension into South America are discussed. Expected +2°C climate warming is predicted to increase the potential year-round range of screwworm in the SE USA.

Gutierrez A.P., Ponti L., 2014. The new world screwworm: prospective distribution and role of weather in eradication. Agricultural and Forest Entomology, http://dx.doi.org/10.1111/afe.12046

Monday, December 2, 2013

Asian citrus psyllid and citrus greening disease

The invasive Asian citrus psyllid Diaphorina citri Kuwayama vectors the bacterial pathogen ‘Candidatus Liberibacter asiaticus’ that is the putative causal agent of citrus greening disease (Huanglongbing disease) in citrus in many areas of the world. The capacity to predict the potential geographic distribution, phenology and relative abundance of the pest and disease is pivotal to developing sound policy for their management. A weather-driven physiologically based demographic model (PBDM) system is developed that summarizes the available data in the literature, and used to assess prospectively the geographic distribution and relative abundance of citrus, the psyllid, its parasitoid (Tamarixia radiata Waterston), and citrus greening disease in North America and the Mediterranean Basin. The potential for natural and biological control of citrus psyllid is examined prospectively.

Gutierrez A.P., Ponti L., 2013. Prospective analysis of the geographic distribution and relative abundance of Asian citrus psyllid (Hemiptera: Liviidae) and citrus greening disease in North America and the Mediterranean Basin. Florida Entomologist, 96:1375-1391. http://dx.doi.org/10.1653/024.096.0417