Variation in the intermittent buzzing songs of male medflies (diptera: tephritidae) associated with geography, mass-rearing, and courtship success

Varios aspectos de los patrones temporales de los sonidos del zumbido intermitente producido durante el cortejo pre-copulatório de los machos de la mosca del Mediterráneo variaron entre moscas silvestres de Costa Rica, Argentina y Hawaii, y entre moscas de sepas de cría masiva de Costa Rica, Argentina, Mexico y Hawaii. No se presentaron diferencias consistentes cuando se compararon las sepas de cría masiva en Costa Rica, Argentina y Hawaii con moscas silvestres de los sitios de origen. Los sonidos producidos durante cortejos que terminaron en cópulas no difieron de los sonidos producidos durante cortejos que llevaron a montas que fracasaron en moscas de Costa Rica y Argentina. Pero en sepas de todos los sitios los zumbidos intermitentes que incluyeron pequeñas pausas tuvieron una mayor probabilidad de no terminar en un intento de monta. Los zumbidos intermitentes de las moscas de las crias masivas tuvieron una tendencia leve a interumpirse mas frecuentemente.Many aspects of the temporal pattern of sounds produced during the intermittent buzzing displays of pre-copulatory courtship by male medflies varied between wild flies from Costa Rica, Argentina, and Hawaii, and between mass-reared flies from Costa Rica, Argentina, Mexico, and Hawaii. There were no consistent differences when mass-reared strains were compared with the wild strains from the area where they originated in Costa Rica, Argentina and Hawaii. Buzzing sounds produced prior to successful mounting attempts did not differ consistently from those preceding unsuccessful mounts in flies from Costa Rica and Argentina. In strains from all sites, however, courtships in which buzzes were interrupted were more likely not to result in mounting of the female. There was a weak tendency for interruptions to be more common in mass-reared strains.Universidad de Costa Rica. Universidad de Buenos Aires. El Colegio de la Frontera Sur, Tapachula, Chiapas, Mexico. USDA-ARS.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Pension systems compared : a polarised perspective, a diverse reality

Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004Globalisation and international competition have a spillover effect on the reforms of pension systems that imposes a similar pattern of dismantling, hardening access to pensions, reducing expenditure and retrenchment in said reforms. The comparative analysis of four countries with different pension systems: two liberal (United Kingdom and Chile) and another two with contributory-proportional systems (Spain and Argentina) serves to determine the details of the reform processes, which discursively seem to have a shared pattern recommended by the international financial and economic institutions. But the reality of the four case studies shows considerable differences in the implementation of the pension reform policies. The reforms depend on the societal context, institutions, history, the role of unions, the government in power, demographic factors and economic perspectives, among other matters. Many countries need to sustain pension systems because they are associated with many pensioners' political vote. Therefore, the spillover effect of globalisation and the convergence in certain uniform patterns of reforms is far from reality in the four countries, and as such, the measures adopted are specific for each country

Conceptual framework and rationale

The sterile insect technique (SIT) has been shown to be an effective and sustainable genetic approach to control populations of selected major pest insects, when part of area-wide integrated pest management (AW-IPM) programmes. The technique introduces genetic sterility in females of the target population in the field following their mating with released sterile males. This process results in population reduction or elimination via embryo lethality caused by dominant lethal mutations induced in sperm of the released males. In the past, several field trials have been carried out for mosquitoes with varying degrees of success. New technology and experience gained with other species of insect pests has encouraged a reassessment of the use of the sterility principle as part of integrated control of malaria vectors. Significant technical and logistic hurdles will need to be overcome to develop the technology and make it effective to suppress selected vector populations, and its application will probably be limited to specific ecological situations. Using sterile males to control mosquito vector populations can only be effective as part of an AW-IPM programme. The area-wide concept entails the targeting of the total mosquito population within a defined area. It requires, therefore, a thorough understanding of the target pest population biology especially as regards mating behaviour, population dynamics, dispersal and level of reproductive isolation. The key challenges for success are: 1) devising methods to monitor vector populations and measuring competitiveness of sterile males in the field, 2) designing mass rearing, sterilization and release strategies that maintain competitiveness of the sterile male mosquitoes, 3) developing methods to separate sexes in order to release only male mosquitoes and 4) adapting suppression measures and release rates to take into account the high reproductive rate of mosquitoes. Finally, success in area-wide implementation in the field can only be achieved if close attention is paid to political, socio-economic and environmental sensitivities and an efficient management organization is established taking into account the interests of all potential stakeholders of an AW-IPM programme

Trends in lipid and protein contents during medfly aging: An harmonic path to death

Survival and egg-laying trends were investigated in Mediterranean fruit flies (Cerotitis corpitata) adults maintained on a sucrose-only diet, or on a full diet that consisted of a 3:1 sucrose and yeast hydrolizate mixture. In addition, we followed the total individual lipid and protein contents of aging flies in a cohort. Survival trends and life expectancy parameters at eclosion for males and females on full diet and for males on sucrose only were very similar. In contrast, the mortality of females on sucrose only was high early in life, but then slowed down. Egg-laying was ten times greater in female flies on full diet than in flies on sucrose only. Lipid contents in males and females on both types of diets were very similar, and harmonically oscillated with an amplitude of approximately 10 days. Successive crests of lipids tended to be smaller with the ageing of the cohort, and lipids contents significantly dropped at very advanced ages and close to the maximal age of the whole cohort. Protein contents of flies maintained on a full diet were high and stayed at a constant level throughout the entire life of the cohort. Protein levels in males and females on sucrose only dropped drastically during the first days of adult life, but then stayed stable at a low level until advanced ages. We propose that the synchronous rhythmic oscillation in lipid contents of male and female flies seems to be independently set by an internal clock. Protein reserves are allocated according to the access to protein food sources and these levels of protein are closely associated to egg production and mortality. Our results are discussed in view of resource allocation during reproduction and senescence