Sustainable crop production: Novel strategies for the control of dipteran pests

Neuropeptide signalling systems present promising avenues for the development of new pest control agents due to their integral roles in insect homeostasis, development, and behaviour. This project primarily examines the crop of the foregut, a muscular organ presents in almost all but not exclusively in the order Diptera, serving the dual purposes of food storage and regurgitation. Myosuppressin and its receptors, which are well-conserved across insect orders, are known to inhibit muscle contractions in the gut, positioning them as prime candidates for disrupting gut function. A critical aspect of this study is understanding that only when ingested food efficiently passes through the foregut can the animal continue its feeding process, highlighting a potential target area for intervention. Using mass spectrometry and immunohistochemistry, we confirmed the identity and spatial distribution of this peptide in the foreguts of two economically significant agricultural pests; cabbage root fly, Delia radicum and medfly, also known as Mediterranean fruit fly, Ceratitis capitata. Our physiological findings highlight myosuppressin capability to significantly inhibit spontaneous crop contractions, responding even to nano- and pico-molar peptide concentrations. Leveraging the adaptable genetics of Drosophila melanogaster, we delved into the potential roles of two myosuppressin G-protein-coupled receptors, DmsR-1 and DmsR-2, in regulating crop muscle contractions. Employing knock-out mutants for both receptors, we established that DmsR-1 plays a critical role in the robust inhibition of crop contractions. Myosuppressin was observed to degrade swiftly when exposed to peptidases in crop of D. radicum. Consequently, we tested a biostable myosuppressin receptor agonist, Benzethonium chloride (Bztc), for its potential to disrupt crop function. Microinjections of the native peptide led to complete oviposition inhibition, highlighting a potential new pathway for myosuppressin signalling that warrants further exploration. This finding emphasizes the potential of myosuppressin as an eco-friendly pest control agent. Given the substantial economic implications associated with the medfly, our neuropeptidome analysis offers a rich repository of prospective novel targets. The discussion further delves into the advantages and challenges of harnessing peptidergic signalling for insect control. It particularly addresses the inherent biostability issues of peptides and underscores the necessity for metabolically stable analogues that can engage with peptide receptors while minimizing degradation

PAHs on a west-to-east transect across the tropical Atlantic Ocean

Surface water and atmospheric samples were collected across the tropical Atlantic Ocean on a transect of the R/V Endeavor in summer 2009 and analyzed for polycyclic aromatic hydrocarbons (PAHs). Across the entire tropical Atlantic Ocean, phenanthrene displayed on average highest dissolved concentrations (170 pg L-1), followed by pyrene (70 pg L-1) and fluoranthene (30 pg L-1). The Amazon plume was characterized by elevated dissolved concentrations of phenanthrene and benzo(g,h,i)fluoranthene. The warm eddy that we accidentally sampled at 66 W displayed highest concentrations of PAHs across the entire cruise, with phenanthrene, pyrene, and fluoranthrene all \u3e1 ng L-1. After having crossed the warm core, concentrations decreased back to previous levels. Samples taken in the Gulf Stream were below detection limit for all parent PAHs, implying very efficient removal processes. Dissolved dimethylphenanthrenes were frequently detected in the samples from the southern hemisphere, the Amazon plume, and in samples characteristic of the Gulf Stream and the U.S. East Coast. Atmospheric concentrations were dominated by gas-phase fluoranthene, pyrene, phenanthrene, and retene. Air-water gradients indicated that PAHs are mostly undergoing net deposition across the tropical Atlantic Ocean, with conditions closer to equilibrium off the U.S. East Coast and in Rhode Island Sound. © 2013 American Chemical Society

Comparability of long-term temporal trends of POPs from co-located active and passive air monitoring networks in Europe

The comparability of data from active (ACT) and passive sampling (PAS) of persistent organic pollutants (POPs) in air is hindered by uncertainties related to the derivation of sampling rates and concentrations, as well as differences in the duration, volume and frequency of sampling. Although data from ACT have been used extensively in short-term PAS calibration studies, no attempts have been made to evaluate the comparability of long-term trends calculated from PAS to established ACT trends. This is crucial, as continuous long-term ACT is unfeasible in most regions of the world. To address these challenges, we calculated and compared trends for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) at the six sites in Europe with at least 5 years of co-located ACT and PAS data (2012–2016): Birkenes, Košetice, Pallas, Råö, Stórhöfði and Zeppelin. Strong agreement of ACT and PAS trends was observed for most OCPs and PCBs. Apart from two PCBs at Stórhöfði, all pairs of ACT and PAS trends followed the same direction. However, differences in the magnitude, significance and confidence intervals of their slopes were observed for some compounds and were primarily attributed to the short duration of the PAS time series. Despite some limitations, our results suggest that the comparability of ACT and PAS POP trends will continue to improve with additional years of data. This study confirms the suitability of PAS for the calculation of long-term POP trends in air, and highlights the importance of continuous sampling at established monitoring sites with consistent analytical methods.ISSN:2050-7887ISSN:2050-789

PAHs on a West-to-East Transect Across the Tropical Atlantic Ocean

Surface water and atmospheric samples were collected across the tropical Atlantic Ocean on a transect of the R/V <i>Endeavor</i> in summer 2009 and analyzed for polycyclic aromatic hydrocarbons (PAHs). Across the entire tropical Atlantic Ocean, phenanthrene displayed on average highest dissolved concentrations (170 pg L^–1), followed by pyrene (70 pg L^–1) and fluoranthene (30 pg L^–1). The Amazon plume was characterized by elevated dissolved concentrations of phenanthrene and benzo­(g,h,i)­fluoranthene. The warm eddy that we accidentally sampled at 66° W displayed highest concentrations of PAHs across the entire cruise, with phenanthrene, pyrene, and fluoranthrene all >1 ng L^–1. After having crossed the warm core, concentrations decreased back to previous levels. Samples taken in the Gulf Stream were below detection limit for all parent PAHs, implying very efficient removal processes. Dissolved dimethylphenanthrenes were frequently detected in the samples from the southern hemisphere, the Amazon plume, and in samples characteristic of the Gulf Stream and the U.S. East Coast. Atmospheric concentrations were dominated by gas-phase fluoranthene, pyrene, phenanthrene, and retene. Air–water gradients indicated that PAHs are mostly undergoing net deposition across the tropical Atlantic Ocean, with conditions closer to equilibrium off the U.S. East Coast and in Rhode Island Sound

Trends of Diverse POPs in Air and Water across the Western Atlantic Ocean: Strong Gradients in the Ocean but Not in the Air

Oceans have remained the least well-researched reservoirs of persistent organic pollutants (POPs) globally, due to their vast scale, difficulty of access, and challenging (trace) analysis. Little data on POPs exists along South America and the effect of different currents and river plumes on aqueous concentrations. Research cruise KN210-04 (R/V Knorr) offered a unique opportunity to determine POP gradients in air, water, and their air-water exchange along South America, covering both hemispheres. Compounds of interest included polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenylethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs). Remote tropical Atlantic Ocean atmospheric concentrations varied little between both hemispheres; for HCB, BDEs 47 and 99, they were ∼5 pg/m3, PCBs were ∼1 pg/m3, α-HCH was ∼0.2 pg/m3, and phenanthrene and other PAHs were in the low 100s pg/m3. Aqueous concentrations were dominated by PCB 52 (mean 4.1 pg/L), HCB (1.6 pg/L), and β-HCH (1.9 pg/L), with other compounds \u3c1 pg/L. Target PCBs tended to undergo net volatilization from the surface ocean, while gradients indicated net deposition for a-HCH. In contrast to atmospheric concentrations, which were basically unchanged between hemispheres, we detected strong gradients in aqueous POPs, with mostly nondetects in the tropical western South Atlantic. These results highlight the importance of currents and loss processes on ocean scales for the distribution of POPs

Persistence, bioaccumulation and vertical transfer of pollutants in long-finned pilot whales stranded in Chilean Patagonia

International audienc

Giordan Lighthouse - a gaw station on the island of Gozo in the central Mediterranean; summary of results obtained concerning shipping emissions, volcanic plumes and other anthropogenic emissions

We have been studying anthropogenic emissions in the Central Mediterranean over the last 18 years with a major instrument upgrade 3 years ago. We conclude that the major sources of emissions are shipping, volcanic plumes from Etna as well as local emissions from cities in the Mediterranean basin. We present a summary of our methods and results in this paper.peer-reviewe

Air and seawater pollution and air–sea gas exchange of persistent toxic substances in the Aegean Sea: spatial trends of PAHs, PCBs, OCPs and PBDEs

Near-ground air (26 substances) and surface seawater (55 substances) concentrations of persistent toxic substances (PTS) were determined in July 2012 in a coordinated and coherent way around the Aegean Sea based on passive air (10 sites in 5 areas) and water (4 sites in 2 areas) sampling. The direction of air–sea exchange was determined for 18 PTS. Identical samplers were deployed at all sites and were analysed at one laboratory. hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs) as well as dichlorodiphenyltrichloroethane (DDT) and its degradation products are evenly distributed in the air of the whole region. Air concentrations of p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and o,p′-DDT and seawater concentrations of p,p′-DDE and p,p′-DDD were elevated in Thermaikos Gulf, northwestern Aegean Sea. The polychlorinated biphenyl (PCB) congener pattern in air is identical throughout the region, while polybrominated diphenylether (PBDE)patterns are obviously dissimilar between Greece and Turkey. Various pollutants, polycyclic aromatic hydrocarbons (PAHs), PCBs, DDE, and penta- and hexachlorobenzene are found close to phase equilibrium or net-volatilisational (upward flux), similarly at a remote site (on Crete) and in the more polluted Thermaikos Gulf. The results suggest that effective passive air sampling volumes may not be representative across sites when PAHs significantly partitioning to the particulate phase are included.Granting Agency of the Czech Republic (312334); Czech Ministry of Education (LO1214--LM2011028); European Social Fund (CZ.1.07/2.3.00/30.0037); European Commission FP7 (262254 ACTRIS

Contamination Profile of DDTs in the Shark Somniosus microcephalus from Greenland Seawaters

DDT isomers were detected in all the liver and muscle samples of Greenland sharks Somniosus microcephalus (n = 15) caught in Greenland seawaters. The mean concentrations of ΣDDTs (sum of o,p’ and p,p’ DDT, DDD, and DDE isomers) were 1094 ± 818 ng/g lipid weight (lw) in the muscle and 761 ± 416 ng/g lw in the liver. The p,p’-DDE accounted for 48% ± 41% and 53% ± 54% of the total DDT residue in the white muscle and liver, respectively. The lipid content was 48% ± 10% in the muscle and 43% ± 17% in the liver. Female sharks showed the highest concentrations of ΣDDTs. The youngest shark showed higher concentrations of ΣDDTs in the liver than the older sharks. To our knowledge, this is one of the few investigations on DDT levels in S. microcephalus where concentrations were correlated to lipid content and sex/size