Ecology and diversity of mosquito larvae in ponds and lagoons of Northwestern Spain.

Galicia, located in the northwestern part of Spain, has a great number and variety of aquatic ecosystems where mosquitoes can breed. Despite the sanitary relevance of these insects, studies on mosquito populations in the region are still scarce. The field research was carried out in 48 sampling points (27 continental lagoons, 12 coastal lagoons and 9 temporary ponds) throughout the entire Galician territory. The samples were collected intermittently and seasonally through different water quality monitoring projects between 2001 and 2017. More than 1500 mosquito larvae belonging to 10 species of five genera (Aedes, Anopheles, Coquillettidia, Culex and Culiseta) were identified. Anopheles (Anopheles) maculipennis s.l. Meigen was the most widely distributed species in the study, being especially dominant in rural areas. In contrast, Culex (Culex) pipiens Linnaeus and Culex (Culex) theileri Theobald showed a preference for breeding in urban areas. New contributions to the knowledge about the larval ecology and distribution of these mosquito species are made throughout this study, including information about the tolerance of each species to water parameters (temperature, pH, dissolved oxygen and conductivity). Likewise, the relationship between culicid diversity and the habitat characteristics of the breeding sites (water body type, climate and level of anthropization) is discussed.

Galicia (NO España) presenta un gran número y variedad de ecosistemas acuáticos donde los mosquitos pueden criar. A pesar del interés sanitario de estos insectos, los estudios sobre las poblaciones de mosquitos en la región aún son escasos. El área de estudio se compone de 48 puntos de muestreo (27 lagunas continentales, 12 lagunas costeras y 9 charcas temporales) a lo largo de todo el territorio gallego. Las muestras fueron recogidas de forma intermitente y estacional mediante diferentes proyectos de monitoreo sobre la calidad del agua entre 2001 y 2017. Se identificaron más de 1500 larvas de mosquitos pertenecientes a diez especies y cinco géneros (Aedes, Anopheles, Coquillettidia, Culex y Culiseta). Anopheles (Anopheles) maculipennis s.l. Meigen fue la especie mejor representada en el estudio, siendo especialmente dominante en áreas rurales. Por el contrario, Culex (Culex) pipiens Linnaeus y Culex (Culex) theileri Theobald mostraron una preferencia por criar en áreas urbanas. A través del presente estudio se realizan nuevas contribuciones al conocimiento de la ecología y la distribución de diferentes especies de mosquitos, incluyéndose información sobre la tolerancia de cada una de las especies a parámetros del agua (temperatura, pH, oxígeno disuelto y conductividad). Así mismo, se discute la relación entre la diversidad de culícidos y las características de las zonas de cría (tipo de masa de agua, clima y nivel de antropización).

Local environment rather than past climate determines community composition of mountain stream macroinvertebrates across Europe.

Community assembly is determined by a combination of historical events and contemporary processes that are difficult to disentangle, but eco-evolutionary mechanisms may be uncovered by the joint analysis of species and genetic diversity across multiple sites. Mountain streams across Europe harbour highly diverse macroinvertebrate communities whose composition and turnover (replacement of taxa) among sites and regions remain poorly known. We studied whole-community biodiversity within and among six mountain regions along a latitudinal transect from Morocco to Scandinavia at three levels of taxonomic hierarchy: genus, species and haplotypes. Using DNA barcoding of four insect families (>3100 individuals, 118 species) across 62 streams, we found that measures of local and regional diversity and intraregional turnover generally declined slightly towards northern latitudes. However, at all hierarchical levels we found complete (haplotype) or high (species, genus) turnover among regions (and even among sites within regions), which counters the expectations of Pleistocene postglacial northward expansion from southern refugia. Species distributions were mostly correlated with environmental conditions, suggesting a strong role of lineage- or species-specific traits in determining local and latitudinal community composition, lineage diversification and phylogenetic community structure (e.g., loss of Coleoptera, but not Ephemeroptera, at northern sites). High intraspecific genetic structure within regions, even in northernmost sites, reflects species-specific dispersal and demographic histories and indicates postglacial migration from geographically scattered refugia, rather than from only southern areas. Overall, patterns were not strongly concordant across hierarchical levels, but consistent with the overriding influence of environmental factors determining community composition at the species and genus levels.

New contributions to the knowledge of two riparian mosquitoes in northwestern Spain: Anopheles petragnani and Culex mimeticus (Diptera: Culicidae).

A study was carried out in 345 water ecosystems (rivers, streams, ditches, lagoons, ponds, puddles, rockpools, and artificial containers) throughout the autonomous community of Galicia (NW Spain) during different seasons between 2020 and 2023. The results revealed the first detections of Anopheles (Anopheles) petragnani Del Vechio, 1939 (n = 185) and Culex (Culex) mimeticus Noè, 1899 (n = 12) in the territory, allowing to update and expand the overall knowledge about their distribution and ecology. The breeding preferences of the species were analyzed considering habitat characteristics (land use, water body type, and degree of insolation), geographical variables (latitude, longitude, and altitude), and physical-chemical water parameters (temperature, pH, dissolved oxygen, electrical conductivity, salinity, total dissolved solids, and turbidity). In addition, the relationship between the occurrence of these species and other mosquitoes present in the study area was discussed. Anopheles petragnani is widely distributed in the region and shows breeding preferences for water bodies of fluvial origin, forest environments, and shaded situations. Culex mimeticus was detected sporadically breeding in a pond and in a river in the south of the region, both in industrial and agricultural land uses, and always exposed to the sun. Although the presence of these species may not currently pose a health risk in the region, it is important not neglecting their study since the adequate characterization of their larval biotopes is relevant regarding vector surveillance and control measures.

Modelling the spatial risk of malaria through probability distribution of Anopheles maculipennis s.l. and imported cases.

Malaria remains one of the most important infectious diseases globally due to its high incidence and mortality rates. The influx of infected cases from endemic to non-endemic malaria regions like Europe has resulted in a public health concern over sporadic local outbreaks. This is facilitated by the continued presence of competent Anopheles vectors in non-endemic countries.We modelled the potential distribution of the main malaria vector across Spain using the ensemble of eight modelling techniques based on environmental parameters and the Anopheles maculipennis s.l. presence/absence data collected from 2000 to 2020. We then combined this map with the number of imported malaria cases in each municipality to detect the geographic hot spots with a higher risk of local malaria transmission.The malaria vector occurred preferentially in irrigated lands characterized by warm climate conditions and moderate annual precipitation. Some areas surrounding irrigated lands in northern Spain (e.g. Zaragoza, Logroño), mainland areas (e.g. Madrid, Toledo) and in the South (e.g. Huelva), presented a significant likelihood of A. maculipennis s.l. occurrence, with a large overlap with the presence of imported cases of malaria.While the risk of malaria re-emergence in Spain is low, it is not evenly distributed throughout the country. The four recorded local cases of mosquito-borne transmission occurred in areas with a high overlap of imported cases and mosquito presence. Integrating mosquito distribution with human incidence cases provides an effective tool for the quantification of large-scale geographic variation in transmission risk and pinpointing priority areas for targeted surveillance and prevention.

Comparison of Effectiveness and Selectiveness of Baited Traps for the Capture of the Invasive Hornet Vespa velutina.

The invasive hornet Vespa velutina affects apiculture, biodiversity, and human health. The use of baited traps with the aim of reducing the population and mitigating its impacts is a common practice. However, the lack of impact on the number of colonies and the high capture rate of non-target insects make it controversial. Our objective was to compare the effectiveness and selectiveness of four trap models. We measured effectiveness as the capture rate of V. velutina per day per trap, and selectiveness as the capture rate of V. velutina/capture rate of non-target species. The E trap had better performance with a higher selectiveness and effectiveness. Traps V and X had a higher effectiveness but the lowest selectiveness, with high capture rates of native insects, including threatened species. The R trap had the lowest effectiveness and selectiveness. Results show that small changes in the design can contribute to achieving more sustainable tools. Otherwise, with the current tools, bait trapping continues to be non-sustainable from an environmental perspective due to the impacts on native biodiversity.

Method for Nest Detection of the Yellow-Legged Hornet in High Density Areas.

The Asian hornet Vespa velutina is a social predator that has invaded several countries of Europe and Asia, impacting pollinators, apiculture and human health. One of the few effective control methods developed so far is the early destruction of nests. However, they are often built within dense vegetation, being difficult to detect. The aim of the method described here is to detect nests with a simple procedure, utilizing readily available materials, for widespread use in infested areas. The method has two phases, the first phase involves capturing and marking hornets, lured to a protein bait, and recording the flight directions of individuals to the nest and the time needed to complete a bait-nest-bait round trip, to estimate the distance. Collecting this information from two (or more) bait stations allows to delineate the approximate location of the nest. The second phase aims to determine the precise location of the nest, using sugary baits in the vicinity of the nest and conspicuous marks attached to the released hornets, to visually follow them up to their nest. This method is an alternative to other methods that are either ineffective in areas with high nest density or require expensive equipment and specialized training.

Effectiveness of electric harps in reducing Vespa velutina predation pressure and consequences for honey bee colony development.

BACKGROUND: Vespa velutina has become a species of concern in invaded regions of Europe and Asia, due to its impacts on biodiversity, apiculture and society. This hornet, a ferocious hunter of pollinating insects, poses a serious threat to biodiversity and pollination services. Despite ongoing efforts, its extermination in continental Europe is hampered by a lack of effective control methods, thus effective mitigation measures are primary concerns. The aims of this work were: (i) to study the effects of V. velutina predating on honey bee colonies, and (ii) to assess the effectiveness of electric harps in reducing hunting pressure and predation. We assessed the predation pressure and compared honey bee colony performance, body weight of workers, and winter survivorship for protected versus unprotected colonies in 36 experimental hives across three apiaries. RESULTS: Electric harps protected honey bees by reducing predation pressure and therefore mitigating foraging paralysis. Consequently, foraging activity, pollen income, brood production and worker body weight were higher in protected colonies which in turn showed greater winter survivorship than those that were unprotected, especially at sites with intermediate to high levels of predation. CONCLUSION: The predation of V. velutina affects foraging activity, breeding, body weight and colony survivorship of Apis mellifera. Electric harps contribute significantly to mitigate the impact of this invasive hornet on apiaries; however, they should be deployed in tandem with additional measures to preserve honey bee colony stocks, such as facilitating access to food sources for colonies during the periods of highest predation pressure. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A biogeochemical approach to understanding the accumulation patterns of trace elements in three species of dragonfly larvae: evaluation as biomonitors.

The accumulation patterns of different trace elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were studied in three species of dragonfly larvae (Cordulegaster boltoni, Boyeria irene and Onychogomphus uncatus). Additionally these species were assessed as potential biomonitors in a lotic ecosystem (Louro River, Spain). Element concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) in both dragonfly larvae and river sediments. The surface of the larvae was observed and analyzed with scanning electron microscopy (SEM). A desorption test was used to establish the percentage of element adsorbed into the exoskeleton. Field biomonitoring studies were made considering the first part of the river as a control area in relation to the second part, which was severely polluted by industrial and domestic activities. Upon application of principal component analysis (PCA), two different element groups were found in relation to element bioaccumulation. Cu, Cd and Zn were mainly associated with the inner part of the larvae. As, Cr, Fe, Mn, Ni and Zn were found on the outer body parts, related with deposition of oxyhydroxides in the hydrocycle. SEM revealed a layer of inorganic particles, similar in composition to fine bed sediments. Significant relations between the element content of this group and that of sediments at the sampling site were found. Differences in bioaccumulation for each of the three species, except for As, were observed. Dragonfly larvae revealed their ability to reflect environmental concentrations of As in freshwater media.

Evolution of microbial dynamics during the maturation phase of the composting of different types of waste.

During composting, facilities usually exert greater control over the bio-oxidative phase of the process, which uses a specific technology and generally has a fixed duration. After this phase, the material is deposited to mature, with less monitoring during the maturation phase. While there has been considerable study of biological parameters during the thermophilic phase, there is less research on the stabilization and maturation phase. This study evaluates the effects of the type of starting material on the evolution of microbial dynamics during the maturation phase of composting. Three waste types were used: sludge from the fish processing industry, municipal sewage sludge and pig manure, each independently mixed with shredded pine wood as bulking agent. The composting system for each waste type comprised a static reactor with capacity of 600L for the bio-oxidative phase followed by stabilization and maturation phase in triplicate 200L boxes for 112days. Phospholipid fatty acids, enzyme activities and physico-chemical parameters were measured throughout the maturation phase. The evolution of the total microbial biomass, Gram + bacteria, Gram - bacteria, fungi and enzymatic activities (ß-glucosidase, cellulase, protease, acid and alkaline phosphatase) depended significantly on the waste type (p<0.001). The predominant microbial community for each waste type remained present throughout the maturation process, indicating that the waste type determines the microorganisms that are able to develop at this stage. While fungi predominated during fish sludge maturation, manure and municipal sludge were characterized by a greater proportion of bacteria. Both the structure of the microbial community and enzymatic activities provided important information for monitoring the composting process. More attention should be paid to the maturation phase in order to optimize composting.