Mosquitoes, including invasive species like the Asian tiger mosquito Aedes albopictus, alongside native species Culex pipiens s.l., pose a significant nuisance to humans and serve as vectors for ...mosquito-borne diseases in urban areas. Understanding the impact of water infrastructure characteristics, climatic conditions, and management strategies on mosquito occurrence and effectiveness of control measures to assess their implications on mosquito occurrence is crucial for effective vector control. In this study, we examined data collected during the local vector control program in Barcelona, Spain, focusing on 234,225 visits to 31,334 different sewers, as well as 1817 visits to 152 fountains between 2015 and 2019. We investigated both the colonization and recolonization processes of mosquito larvae within these water infrastructures. Our findings revealed higher larval presence in sandbox-sewers compared to siphonic or direct sewers, and the presence of vegetation and the use of naturalized water positively influenced larval occurrence in fountains. The application of larvicidal treatment significantly reduced larvae presence; however, recolonization rates were negatively affected by the time elapsed since treatment. Climatic conditions played a critical role in the colonization and recolonization of sewers and urban fountains, with mosquito occurrence exhibiting non-linear patterns and, generally, increasing at intermediate temperatures and accumulated rainfall levels. This study emphasizes the importance of considering sewers and fountains characteristics and climatic conditions when implementing vector control programs to optimize resources and effectively reduce mosquito populations.
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•Mosquitoes use scuppers and ornamental fountains for breeding in urban areas.•Sandbox scuppers harboured more often mosquito larvae than siphonic/endless scuppers.•Larvicidal treatments reduce mosquito larvae, but recolonization occurs within 10–25 days.•Climatic, mainly temperature and accumulated rainfall, affect mosquito populations.•Monitoring and control of mosquito larvae at the breeding sites may improve mosquito control in urban areas.
In this work a constitutive relation for ice at high strain rates and an algorithm for its numerical integration are developed. This model is based on the Drucker–Prager plasticity criteria, which ...allows a different behavior in tension and in compression. In addition a failure criteria, based on pressure cut-offs, is implemented to describe the ice damage. In order to validate the constitutive model, numerical simulations were compared with experimental results, in which ice cylinders were impacted against a steel plate, allowing the measurement of the contact load. Three different numerical solvers are used in order to analyze its performance to appropriately modeling the ice behavior.
In this work, the analysis of the impactor mass effect on the behaviour of carbon/epoxy woven laminates under low velocity impact is carried out. To this end experimental test were performed by means ...of a drop weigh tower in a range of energies varying from 10 to 110J, and using three different impactor masses. Two different laminate thicknesses were considered in order to take into account its possible influence. An analysis of the impact tests is performed using the Composite Structure Impact Performance Assessment Program, in order to observe the influence of impactor mass. Once impacted, the laminates were inspected by means of a C-Scan (to quantify the delamination extension) and a phased array ultrasonic system (to analyse the failure through the thickness); this non-destructive analysis will determine the influence of the impactor mass on the laminate failure.
Molecular studies indicate that Phlebotomine sandflies (Diptera: Psychodidae) blood feed on many vertebrate species, of which only a few are proven parasite reservoirs. Investigating sandfly vector ...feeding preferences is therefore important and requires taking into account the availability and accessibility of host species. In terms of the latter, it is necessary to consider the metabolic cost to the insect of reaching the host and moving on to a suitable breeding site. The present study used statistical modelling to compare the feeding patterns of Phlebotomus perniciosus (n = 150), Phlebotomus papatasi (n = 35) and Phlebotomus ariasi (n = 7) on each of an average of 30 host species in a wildlife park in Murcia, Spain. Sandfly feeding movement costs were estimated as a function of the distance and altitude gradients saved by the insect, assuming that they displayed ‘site fidelity’. Most (87%) engorged females were caught <100 m from the host on which they had fed. Although the percentage of bloodmeals was highest on fallow deer (Dama dama) (30%) and red deer (Cervus elaphus) (26%), the predicted feeding probability after considering movement cost was highest for red deer and common eland (Taurotragus oryx), and positively associated with host census. These results suggest that, under similar circumstances, sandflies prefer to feed on some host species more than on others.
Cost‐path analysis revealed that, given the choice, Phlebotomus perniciosus, Phlebotomus papatasi and Phlebotomus ariasi preferred to blood feed on some host species more than on others.
Feeding trajectories were shorter and required lower movement costs than would be expected by chance.
Sandflies tended to blood feed on higher‐census host species; predicted feeding probability was highest for red deer (Cervus elaphus) and common eland (Taurotragus oryx) compared with other available host species.
•Modeling of drilling of CFRPs involves elevated computational cost.•Simplified models lead to reduced computational time.•Complete and simplified models were compared in terms of delamination ...prediction.•The simplified model, slightly overestimates the delamination factor.•The influence of thrust force, clamping area and the stacking sequence is studied.
Delamination is one of the undesired effects of machining using non appropriate cutting parameters or worn drill. Finite element modeling of drilling of Carbon Fiber Reinforced Polymer (CFRP) composites is an interesting tool for damage prediction. Recently, complete modeling of the process including the rotatory movement of the drill, penetration in the composite plate and element erosion has been developed in the scientific literature. Computational cost of these complex models is a great disadvantage when comparing them with simplified models that consider the drill acting like a punch that pierces the laminate. In this paper both complete and simplified models were developed and compared in terms of delamination prediction. The simplified model, presenting reduced computational cost, slightly overestimates the delamination factor when compared with the complex model. The influence on delamination of thrust force, clamping area at the bottom surface of the laminate and the stacking sequence is studied using the simplified model.
Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the ...pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood‐feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood‐feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.
•The main failure mechanism that appears in the composite panels is delamination.•Most of the panels exhibit no-delaminated or almost full delaminated area.•A dimensionless variable that describes ...the influence of parameters is presented.
This work analyses the behaviour of carbon/epoxy unidirectional laminates subjected to high velocity impacts of ice spheres. To this end, ice projectiles were launched against composite laminates in a wide range of velocities (50 − 250 m/s). Two different ice diameters (40 and 50 mm) and two laminate thicknesses (4 and 6 mm) were considered. The internal damage was measured using both destructive and non-destructive techniques, which allow an accurate quantification of the delaminated area. Finally the influence of the different parameters considered on the damage of the laminate is analysed by means of a dimensionless variable.
Hydrodynamic ram (HRAM) is a phenomenon that occurs when a high-kinetic energy object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid ...to the surrounding structure, increasing the risk of catastrophic failure and excessive structural damage. This is of particular concern in the design of wing fuel tanks for aircraft since it has been identified as one of the important factors in aircraft vulnerability. In the present paper, the commercial finite-element code LS-DYNA has been used to simulate an HRAM event created by a steel spherical projectile impacting a water-filled aluminium square tube. Two different formulations (ALE and SPH) are employed to reproduce the event. Experimental tests which indicate the pressure at different points of the fluid, displacement of the walls and cavity evolution for different impact velocities are compared with the numerical results in order to assess the validity and accuracy of both ALE and SPH techniques in reproducing such a complex phenomenon.
There is increasing evidence that sexual selection operates in females and not only in males. However, the function of female signals in intrasexual competition has been little studied in species ...with conventional sex roles. In the Iberian populations of the pied flycatcher (Ficedula hypoleuca), some females express a white forehead patch, a trait that in other European populations, only males exhibit and has become a classical example in studies of sexual selection. Here, we investigated whether the expression of this trait plays a role in female-female competition during early breeding stages. To test this hypothesis, we simulated territorial intrusions by challenging resident females with stuffed female decoys expressing or not a forehead patch. We found that resident females directed more attacks per trial and maintained closer distances to non-patched decoys than to patched ones. Also, patched females were more likely to attack the decoy than non-patched females. Interestingly, females were more aggressive against the decoys when their mate was absent. This may indicate that females relax territory vigilance in the presence of their mate or that males interfere in the interaction between competing females. The behavior of resident males was also observed, although it was not affected by decoy’s patch expression. Our findings suggest that the forehead patch plays a role in female intrasexual competition. If the forehead patch signals fighting ability, as it does in males, we may interpret that non-patched females probably avoided repeating costly agonistic encounters with the most dominant rivals.
Mosquito feeding preferences determine host–vector contact rates and represent a key factor in the transmission of vector‐borne pathogens. The semiochemical compounds of which vertebrate odours are ...composed probably play a role in mosquito host choice. Birds spread secretions from uropygial gland over their feathers to protect their plumage, comprising behaviour that may in turn affect odour profiles. Although uropygial secretions are expected to modify the attractiveness of birds to mosquitoes, contradictory findings have been reported. Mosquito species differ in their feeding preferences, with some species feeding mainly on birds (ornithophilic species) and others on mammals (mammophilic species). Consequently, it is possible that ornithophilic and mammophilic species differ in their response to uropygial gland secretions. Using a dual‐choice olfactometer, the present study tests this hypothesis by comparing the behavioural response to uropygial gland secretions from juvenile male and female house sparrows (Passer domesticus) in the ornithophilic Culex pipiens and the mammophilic Aedes (Ochlerotatus) caspius mosquitoes. No differences were found in the response of either mosquito species to the uropygial gland secretions. Therefore, the preference of ornithophilic mosquitoes for avian hosts is apparently not explained by a greater attraction of mosquitoes to the uropygial gland secretion odour when presented in combination with a CO2‐enriched airflow.
The secretion of the uropygial gland of birds have been suggested to play a key role in mosquito attraction.
The attraction of two mosquito species to the uropygial gland secretion of wild birds was tested in a dual‐port olfactometer.
The ornithophilic Culex pipiens and the mammophilic Aedes caspius were not significantly attracted to uropygial gland secretions of house sparrows.
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