Oxidation capacity changes in the atmosphere of large urban areas in Europe: Modelling and experimental campaigns in atmospheric simulation chambers.

Air pollution is a major concern for human health and the environment. Consequently, environmental standards have become stricter to improve air quality. Thanks to this, the ambient levels of O precursors such as VOCs and NO have decreased.

Antibiotic treatment reduces fecundity and nutrient content in females of Anastrepha fraterculus (Diptera: Tephritidae) in a diet dependent way.

Insect microbiota, particularly, gut bacteria has recently gained especial attention in Tephritidae fruit flies, being Enterobacteriaceae the predominant bacterial group. This bacterial group has been postulated to contribute to the fitness of fruit flies through several life-history traits. Particularly in Anastrepha fraterculus, removal of Enterobacteria from male gut via antibiotic treatment impaired their mating behavior.

The role of genetically engineered soybean and Amaranthus weeds on biological and reproductive parameters of Spodoptera cosmioides (Lepidoptera: Noctuidae).

Background: In soybean fields containing insecticide- and herbicide-resistant genetically engineered varieties, some weed species have increasingly become difficult to manage and may favor the population growth of secondary pests like Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae). To test this hypothesis, we measured life-history traits, population growth parameters and adult nutrient content of S. cosmioides reared on foliage from four Amaranthus species, from Cry1Ac Bt and non-Bt soybean varieties, and on meridic artificial diet.

Trends in stabilisation of Criegee intermediates from alkene ozonolysis.

Criegee Intermediates (CI), formed in the ozonolysis of alkenes, play a central role in tropospheric chemistry as an important source of radicals, with stabilised CI (SCI) able to participate in bimolecular reactions, affecting climate through the formation of inorganic and organic aerosol. However, total SCI yields have only been determined for a few alkene systems, while speciated SCI yields from asymmetrical alkenes are almost entirely unknown. Here we report for the first time a systematic experimental exploration of the stabilisation of CH2OO and (CH3)2COO CI, formed from ten alkene-ozone systems with a range of different sizes and structures, under atmospherically relevant conditions in the EUPHORE chamber.

Pheromone emission patterns and courtship sequences across distinct populations within Anastrepha fraterculus (Diptera-Tephritidae) cryptic species complex.

Sexual behavioural isolation can result from sexual selection and represents a relevant factor associated with the speciation process. We analysed the pheromone emission pattern and the courtship of males of five different populations of the Anastrepha fraterculus cryptic complex: Brazil (Vacaria, Tucumán and Piracicaba), Colombia and Peru. The time of pheromone emission was recorded in each population every 30 min during the day.

Atmospheric Oxidation of a Thiocarbamate Herbicide Used in Winter Cereals.

The gas-phase atmospheric degradation of prosulfocarb (a widely used thiocarbamate herbicide in winter cereals) at different NOx concentrations was investigated at the large outdoor European PHOtoREactor (EUPHORE) in Valencia, Spain. Photolysis under sunlight conditions and reaction with ozone were shown as unimportant. The rate constant for the reaction of prosulfocarb with OH radicals was determined as k = (2.

Atmospheric degradation of the organothiophosphate insecticide - Pirimiphos-methyl.

The gas phase atmospheric degradation of pirimiphos-methyl (a widely used organophosphate insecticide and acaricide in many European regions) has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. Its photolysis has been studied under sunlight conditions and its reaction rate constant with OH radicals was measured by the relative rate method. The reaction with ozone was also investigated.

Risk assessment of airborne pesticides in a Mediterranean region of Spain.

A risk assessment strategy based on the quantitative target analysis and semi-quantitative retrospective screening determination of pesticides in PM10 has been developed. The proposed methodology was applied to 345 real samples from nine stations of a Mediterranean area in Spain, and the risk was assessed for adult, children and infants. Forty pesticides were detected with average concentrations ranging from 8 to 30,000pgm.

Relevant genetic differentiation among Brazilian populations of Anastrepha fraterculus (Diptera, Tephritidae).

We used a population genetic approach to detect the presence of genetic diversity among six populations of Anastrepha fraterculus across Brazil. To this aim, we used Simple Sequence Repeat (SSR) markers, which may capture the presence of differentiative processes across the genome in distinct populations. Spatial analyses of molecular variance were used to identify groups of populations that are both genetically and geographically homogeneous while also being maximally differentiated from each other.

Evaluating mating compatibility within fruit fly cryptic species complexes and the potential role of sex pheromones in pre-mating isolation.

The study of sexual behavior and the identification of the signals involved in mate recognition between con-specifics are key components that can shed some light, as part of an integrative taxonomic approach, in delimitating species within species complexes. In the Tephritidae family several species complexes have received particular attention as they include important agricultural pests such as the Ceratitis fasciventris (Bezzi), Ceratitis anonae (Graham) and Ceratitis rosa Karsch (FAR) complex, the Bactrocera dorsalis (Hendel) complex and the Anastrepha fraterculus (Wiedemann) complex. Here the value and usefulness of a methodology that uses walk-in field cages with host trees to assess, under semi-natural conditions, mating compatibility within these complexes is reviewed, and the same methodology to study the role of chemical communication in pre-mating isolation among Anastrepha fraterculus populations is used.

Resolving cryptic species complexes of major tephritid pests.

An FAO/IAEA Co-ordinated Research Project (CRP) on "Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade" was conducted from 2010 to 2015. As captured in the CRP title, the objective was to undertake targeted research into the systematics and diagnostics of taxonomically challenging fruit fly groups of economic importance. The scientific output was the accurate alignment of biological species with taxonomic names; which led to the applied outcome of assisting FAO and IAEA Member States in overcoming technical constraints to the application of the Sterile Insect Technique (SIT) against pest fruit flies and the facilitation of international agricultural trade.

Insights into the Formation and Evolution of Individual Compounds in the Particulate Phase during Aromatic Photo-Oxidation.

Secondary organic aerosol (SOA) is well-known to have adverse effects on air quality and human health. However, the dynamic mechanisms occurring during SOA formation and evolution are poorly understood. The time-resolved SOA composition formed during the photo-oxidation of three aromatic compounds, methyl chavicol, toluene and 4-methyl catechol, were investigated at the European Photoreactor.

Atmospheric degradation of lindane and 1,3-dichloroacetone in the gas phase. Studies at the EUPHORE simulation chamber.

The gas-phase degradation of lindane (γ-isomer of hexachlorocyclohexane) towards OH radical was investigated under atmospheric conditions at the large outdoor European simulation chamber (EUPHORE) in Valencia, Spain. The rate coefficient for the reaction of hydroxyl radicals with lindane was measured using a conventional relative rate technique leading to a value of kOH(lindane)=(6.4±1.

Male Sexual Behavior and Pheromone Emission Is Enhanced by Exposure to Guava Fruit Volatiles in Anastrepha fraterculus.

Background: Plant chemicals can affect reproductive strategies of tephritid fruit flies by influencing sex pheromone communication and increasing male mating competitiveness.

Objective And Methodology: We explored whether exposure of Anastrepha fraterculus males to guava fruit volatiles and to a synthetic blend of volatile compounds released by this fruit affects the sexual performance of wild and laboratory flies. By means of bioassays and pheromone collection we investigated the mechanism underlying this phenomenon.

Gas-phase and particulate products from the atmospheric degradation of the organothiophosphorus insecticide chlorpyrifos-methyl.

The phosphorothioate structure is highly present in several organophosphorus pesticides. However, there is insufficient information about its degradation process after the release to the atmosphere and the secondary pollutants formed. Herein, the atmospheric reaction of chlorpyrifos-methyl (o,o-dimethyl o-(3,5,6-trichloropyridin-2-yl) phosphorothioate), is described for semi-urban or rural locations.

Toxic effect of citrus peel constituents on Anastrepha fraterculus Wiedemann and Ceratitis capitata Wiedemann immature stages.

The toxicity of essential oils from the citrus peel has been proposed as the major resistance mechanism offered by citrus to fruit fly infestation. We evaluated the insecticidal activity of the ether extracts from the lemon (Citrus limon [L.] Burm.

The gas-phase degradation of chlorpyrifos and chlorpyrifos-oxon towards OH radical under atmospheric conditions.

The OH initiated oxidation of chlorpyrifos (a widely used insecticide) and its photooxidation product chlorpyrifos-oxon were investigated at the large outdoor European Photoreactor (EUPHORE). The rate constants for reaction of chlorpyrifos and chlorpyrifos oxon with OH radicals were measured using a conventional relative rate method. The value of the OH reaction rate constants with chlorpyrifos and chlorpyrifos-oxon were determined to be k=(9.

Gas-phase degradation of the herbicide ethalfluralin under atmospheric conditions.

The gas-phase degradation of ethalfluralin, N-ethyl-α,α,α-trifluoro-N-(2-methylallyl)-2,6-dinitro-p-toluidine, a widely used herbicide, was investigated under atmospheric conditions at the large outdoor European simulation chamber (EUPHORE) in Valencia, Spain. The photolysis of ethalfluralin was investigated under solar radiation and the mean photolysis rate coefficient was determined: J(ethalfluralin)=(1.3±0.

Export of commercial Hass avocados from Argentina poses negligible risk of Ceratitis capitata (Diptera: Tephritidae) infestation.

Argentina has to meet quarantine restrictions because of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), to export 'Hass' avocados, Persea americana Miller, to certain countries. Hass avocado at the hard, mature green stage is potentially a conditional nonhost for C. capitata and could open export markets without the need for a quarantine treatment.

Host association of Spodoptera frugiperda (Lepidoptera: Noctuidae) corn and rice strains in Argentina, Brazil, and Paraguay.

Spodoptera frugiperda (J.E. Smith) is composed of two genetically distinct strains, the so-called corn strain and the rice strain.

Factors affecting Anastrepha fraterculus female receptivity modulation by accessory gland products.

In the context of the sterile insect technique (SIT), mass-rearing and male irradiation are imperative. Post-teneral treatments such as the addition of protein in adult's male diet and male hormonal treatment are used to improve sexual performance and to accelerate sexual maturation. In this work we investigated the effect of male accessory glands products (AGPs) on female receptivity of the South American fruit fly Anastrepha fraterculus (Wiedemann), and the effect of strain rearing history, male irradiation, male diet and hormonal treatment on AGPs.

Effects of male nutrition on sperm storage and remating behavior in wild and laboratory Anastrepha fraterculus (Diptera: Tephritidae) females.

Male physiological condition can affect his ability to modulate female sexual receptivity. Thus, studying this aspect can have biological and practical implications. Here, we examine how male nutritional status affected the amount of sperm stored, remating rate and refractory period of the tephritid fruit fly Anastrepha fraterculus (Wiedemann) females.