“Step by step”: high frequency short-distance epizoochorous dispersal of aquatic macrophytes

Aquatic macrophytes can successfully colonise and re-colonise areas separated by space and time. The mechanisms underlying such “mobility” are not well understood, but it has often been hypothesised that epizoochory (external dispersal) plays an important role. Yet, there is only limited, and mostly anecdotal, evidence concerning successful epizoochorous dispersal of aquatic macrophytes, particularly in the case of short-distance dispersal. Here we examine in situ and ex situ dispersal of aquatic macrophytes, including three invasive alien species. A high frequency of Lemna minor Linnaeus dispersal was observed in situ, and this was linked to bird-mediated epizoochory. We concluded that wind had no effect on dispersal. Similarly, in an ex situ examination Lemna minuta Kunth and Azolla filiculoides Lamarck, were found to be dispersed with a high frequency by mallard ducks (Anas platyrhynchos). No dispersal was measured for Elodea nuttalli (Planchon) H. St. John. It is concluded that short-distance or “stepping-stone” dispersal via bird-mediated epizoochory can occur with high frequencies, and therefore can play an important role in facilitating colonisation, range expansion and biological invasion of macrophytes.

Approaches to Aquatic Invasive Species Integrated Pest Management Control and Common ID

This PowerPoint presentation goes over the ways in which aquatics pest and weeds can be controlled.

The red swamp crayfish Procambarus clarkii in Europe: Impacts on aquatic ecosystems and human well-being

Procambarus clarkii is currently recorded from 16 European territories. On top of being a vector of crayfish plague, which is responsible for large-scale disappearance of native crayfish species, it causes severe impacts on diverse aquatic ecosystems, due to its rapid life cycle, dispersal capacities, burrowing activities and high population densities. The species has even been recently discovered in caves. This invasive crayfish is a polytrophic keystone species that can exert multiple pressures on ecosystems. Most studies deal with the decline of macrophytes and predation on several species (amphibians, molluscs, and macroinvertebrates), highlighting how this biodiversity loss leads to unbalanced food chains. At a management level, the species is considered as (a) a devastating digger of the water drainage systems in southern and central Europe, (b) an agricultural pest in Mediterranean territories, consuming, for example, young rice plants, and (c) a threat to the restoration of water bodies in north-western Europe. Indeed, among the high-risk species, P. clarkii consistently attained the highest risk rating. Its negative impacts on ecosystem services were evaluated. These may include the loss of provisioning services such as reductions in valued edible native species of regulatory and supporting services, inducing wide changes in ecological communities and increased costs to agriculture and water management. Finally, cultural services may be lost. The species fulfils the criteria of the Article 4(3) of Regulation (EU) No 1143/2014 of the European Parliament (species widely spread in Europe and impossible to eradicate in a cost-effective manner) and has been included in the “Union List”. Particularly, awareness of the ornamental trade through the internet must be reinforced within the European Community and import and trade regulations should be imposed to reduce the availability of this high-risk species.

Alqueva hydro-meteorological experiment(alex): first results of aquatic ecological assessment

The ALqueva hydro-meteorological EXperiment (ALEX) field campaign took place monthly during summer 2014 and consisted in in situ measurements and sampling of water and biological elements, collected from three fixed platforms placed in the lacustrine zone. This integrated overview, including meteorological, environmental and biological results contributes to improve the knowledge of the reservoir dynamics and therefore to propose adequate management measures to preserve the observed biological integrity.

Bacterial community associated to the pine wilt disease insect vectors Monochamus galloprovincialis and Monochamus alternatus

Monochamus beetles are the dispersing vectors of the nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease (PWD). PWD inflicts significant damages in Eurasian pine forests. Symbiotic microorganisms have a large influence in insect survival. The aim of this study was to characterize the bacterial community associated to PWD vectors in Europe and East Asia using a culture-independent approach. Twenty-three Monochamus galloprovincialiswere collected in Portugal (two different locations); twelve Monochamus alternatus were collected in Japan. DNA was extracted from the insects’ tracheas for 16S rDNA analysis through denaturing gradient gel electrophoresis and barcoded pyrosequencing. Enterobacteriales, Pseudomonadales, Vibrionales and Oceanospirilales were present in all samples. Enterobacteriaceae was represented by 52.2% of the total number of reads. Twenty-three OTUs were present in all locations. Significant differences existed between the microbiomes of the two insect species while for M. galloprovincialis there were no significant differences between samples from different Portuguese locations. This study presents a detailed description of the bacterial community colonizing the Monochamus insects’ tracheas. Several of the identified bacterial groups were described previously in association with pine trees and B. xylophilus, and their previously described functions suggest that they may play a relevant role in PWD.

Influence of Baculovirus anticarsia on the growth rate and survival of some nontarget aquatic organisms.

Recently, microbial pest control agents (MPCAs) have been worldwide used to reduce chemical pesticide use and to diminish the high risk of those compounds in the environment. Among various MPCAs, the nuclear polyhedrosis virus Baculovirus anticarsia is widely used in Brazil in the biological control of the velvet bean caterpillar. Although literature data do not show adverse effects of baculoviruses to nontarget organisms, it is necessary to evaluate their toxicity or patogenicity in order to study th environmental risk of those products and to register the formulations in the Brazilian Environmental Regularory Agency - IBAMA. In the presente work, the influence of a Baculovirus anticarsia formulation was evaluted to measure the consequences in the growth rateof the green algae Selenastrum capricornutum, the duckweed Lemna valdiviana and the microcrustacean Daphnia similis. The survival of the fish Hyphessobrycon scholzei exposed during 28 days was also evaluated. No significative adverse effects (P > 0.05) were observed in the test organisms which were exposed to 1-1000 times the maximum calculated pesticide concentration following a direct application to 15 cm layer of water.

Risk assessment of the herbicide clomazone in the aquatic life.

Clomazone (2-(2-chlorophenyl)methyl-4.4-dimethyl-3-isoxazolidinone) is a post emergence herbicide widely used in rice fields in Rio Grande do Sul (Brazil) with high activity against Gramineae at the recommended application rate(AR).of 700g/ha. The herbicide input into the aquatic ecosystem may occur by aerial application or water drainage. The presence of this chemical in the water may affect non-target organisms leading to impairments in the aquatic food chain. Studies were conducted in this work to evaluate the risk of Clomazone using the estimated mean affective concentration (EC50) for the microalgae Selenastrum capricornutum(96h), the duckweed Lemna valdiviana(96h) and the crustacean Daphnia similis(48h). The EC50 values were 11.2; 31.7 and 13.8 mg/l, respectively. According to the obtained data, and considering a direct input of the herbicide in a 10cm column water, the estimated maximum application rate that doesn't cause acute effects is 5.3 AR for S. capricornutum, 6.5 AR for D. similis and 15.0 AR for L. valdiviana. The estimated maximum application rate that doesn't cause chronic effects is 2.0 AR for D. similis, 1.6 AR for S. capricornutum and 4.5 AR for L. valviana.

Effects od y-Fe²O³ nanoparticles on the survival and reproduction of Biomphalaria glabrata (Say, 1818) and their elimination from this benthic aquatic snail.

2016

Agronomic performance of selected sweet potato cultivars under greenhouse and field infested with meloigogyne incognita and soilborne insect pests.

The root knot nematode (RKN), Meloidogyne incognita, is widespread worldwide and a major pathogen of several cultivated crops. The use of resistant genotypes is the most effective and environmentally sound way to manage RKN. In this study, we screened 16 selected sweet potato cultivars including Amanda, Bárbara, Beatriz, Beauregard, Brazlândia Branca, Brazlândia Rosada, Brazlândia Roxa, BRS Amélia, BRS Cuia, BRS Rubissol, Carolina Vitória, Duda, Júlia, Marcela, PA-26/2009, and Princesa obtained from Embrapa and Universidade Federal do Tocantins? germplasm bank. Studies were conducted under greenhouse and field conditions and the agronomic performance of the cultivars was evaluated in a nematode and soilborne insect-infested field. All 16 sweet potato cultivars tested were rated as resistant to this nematode both under greenhouse and field conditions with reproduction factors < 1. In the field infested with M. incognita, sweet potato cultivars Duda, BRS Amélia, Beauregard, Brazlândia Rosada, and Brazlândia Roxa stood out as superior cultivars, with average yield ranging from 26 to 47 tons per ha. Overall, most cultivars exhibited a fusiform to near fusiform root shape, a good characteristic for the market, and were moderately affected by insects (attack incidence 1 to 30%). As global demand for energy continues to rise, selecting new cultivars of sweet potatoes with increased resistance to nematode diseases and with high yield will be important for food security and biofuel production.

Prediction of a low-risk concentration of diflubenzuron to aquatic organisms and evaluation of clay and gravel in reducing the toxicity.

Resumo: Predição da concentração de baixo risco de diflubenzuron para organismos aquáticos e avaliação da argila e brita na redução da toxicidade. O diflubenzuron é um inseticida que além de ser usado agricultura, tem sido amplamente empregado na piscicultura, apesar do seu uso ser proibido nesta atividade. Este composto não consta na lista da legislação brasileira que estabelece limites máximos permissíveis em corpos de água para a proteção das comunidades aquáticas. No presente trabalho, a partir da toxicidade do diflubenzuron em organismos não-alvo, foi calculada a concentração de risco para somente 5% das espécies (HC5). O valor deste parâmetro foi estimado em aproximadamente 7 x 10-6 mg L-1 . Este baixo valor é devido à extremamente alta toxicidade do diflubenzuron para dafnídeos e à grande variação de sensibilidade entre as espécies testadas. Dois matérias de relativamente baixo custo se mostraram eficientes na remoção da toxicidade do diflubenzuron de soluções contendo este composto. Dentre esses materiais, a argila expandida promoveu a redução em aproximadamente 50% da toxicidade de uma solução contendo diflubenzuron. Os resultados podem contribuir para políticas públicas no Brasil relacionadas ao estabelecimento de limites máximos permissíveis de xenobióticos no compartimento aquático. Também, para a pesquisa de matérias inertes e de baixo custo com potencial de remoção de xenobióticos presentes em efluentes da aquicultura ou da agricultura. Abstract: Diflubenzuron is an insecticide that, besides being used in the agriculture, has been widely used in fish farming. However, its use is prohibited in this activity. Diflubenzuron is not in the list of Brazilian legislation establishing maximum permissible limits in water bodies for the protection of aquatic communities. In this paper, according toxicity data of diflubenzuron in non-target organisms, it was calculated an hazardous concentration for only 5% of the species (HC5) of the aquatic community. This parameter value was estimated to be about 7 x 10 -6 mg L -1 . The low value is due to the extreme high toxicity of diflubenzuron to daphnids and to the large variation in sensitivity among the species tested. Two relatively low cost and inert materials were efficient in removing the diflubenzuron from solutions containing this compound. Among these materials, expanded clay shown to promote reduction of approximately 50% of the toxicity of a solution containing diflubenzuron. The results may contribute to the establishment of public policies in Brazil associated to the definition of maximum permissible limits of xenobiotics in the aquatic compartment. This study is also relevant to the search of low cost and inert materials for xenobiotics removal from aquaculture or agricultural effluents.

Methods for objective and interpretative evaluation of function and motor control: gait in perturbed condition and in the aquatic therapy

Gait analysis allows to characterize motor function, highlighting deviations from normal motor behavior related to an underlying pathology. The widespread use of wearable inertial sensors has opened the way to the evaluation of ecological gait, and a variety of methodological approaches and algorithms have been proposed for the characterization of gait from inertial measures (e.g. for temporal parameters, motor stability and variability, specific pathological alterations). However, no comparative analysis of their performance (i.e. accuracy, repeatability) was available yet, in particular, analysing how this performance is affected by extrinsic (i.e. sensor location, computational approach, analysed variable, testing environmental constraints) and intrinsic (i.e. functional alterations resulting from pathology) factors. The aim of the present project was to comparatively analyze the influence of intrinsic and extrinsic factors on the performance of the numerous algorithms proposed in the literature for the quantification of specific characteristics (i.e. timing, variability/stability) and alterations (i.e. freezing) of gait. Considering extrinsic factors, the influence of sensor location, analyzed variable, and computational approach on the performance of a selection of gait segmentation algorithms from a literature review was analysed in different environmental conditions (e.g. solid ground, sand, in water). Moreover, the influence of altered environmental conditions (i.e. in water) was analyzed as referred to the minimum number of stride necessary to obtain reliable estimates of gait variability and stability metrics, integrating what already available in the literature for over ground gait in healthy subjects. Considering intrinsic factors, the influence of specific pathological conditions (i.e. Parkinson’s Disease) was analyzed as affecting the performance of segmentation algorithms, with and without freezing. Finally, the analysis of the performance of algorithms for the detection of gait freezing showed how results depend on the domain of implementation and IMU position.

Agroecological management of insect pests on sugarbeets and lettuce cultivated in organic farming

Two-year field trials were conducted in northern Italy with the aim of developing a trapcrop-based agroecological approach for the control of flea beetles (Chaetocnema tibialis (Illiger), Phyllotreta spp. (Chevrolat) (Coleoptera: Chrysomelidae)) and Lygus rugulipennis Poppius (Hemiptera: Miridae), key pests of sugar beet and lettuce, respectively. Flea beetle damage trials compared a trap cropping treatment, i.e., a sugar beet plot with a border of Sinapis alba (L.) and Brassica juncea (L.) with a control treatment, i.e., a sugar beet plot with bare soil as field border. Sugar beets grown near trap crops showed a significant decrease (≈40%) in flea beetle damage compared to control. Moreover, flea beetle damage varied with distance from the edge of the trap plants, being highest at 2 m from the edge, then decreasing at higher distances. Regarding L. rugulipennis on lettuce two experiments were conducted. A semiochemical-assisted trap cropping trial was supported by another test evaluating the efficacy of pheromones and trap placement. In this trial, it was found that pheromone baited traps caught significantly more specimens of L. rugulipennis than unbaited traps. It was also found that traps placed at ground level produced larger catches than traps placed at the height of 70 cm. In the semiochemical-assisted trap cropping experiment, a treatment where lettuce was grown next to two Alfa-Alfa borders containing pheromone baited traps was compared with a control treatment, where lettuce was grown near bare soil. This experiment showed that the above-mentioned strategy managed to reduce L. rugulipennis damage to lettuce by ≈30%. From these studies, it appears that trap crop-based strategy, alone or with baited traps, made it possible to reduce crop damage to economically acceptable levels and to minimize the need for insecticide treatments, showing that those strategy could be implemented in organic farming as a means of controlling insect pests.

Advancing of risk assessment of pesticides on insect pollinators: beyond honey bees (Apis mellifera L.)

The western honey bee, Apis mellifera L., is currently the model specie for pesticide risk assessment on pollinators with the assumption that the worst-case scenarios for this species are sufficiently conservative to protect other insect pollinators. However, recent studies have showed that wild species may be more sensitive to plant protection products, due to differences in biology and life cycles. Therefore, there is the need to extend the risk assessment within a more ecological approach, in order to ensure that there are no irreversible effects on non-target organisms and in the environment. My dissertation aims to expand the risk assessment to other insect pollinators (including wild and managed pollinators), in order to cover some of the gaps of the current schemes. In this thesis, it is presented three experiments that cover the early stages of a solitary bee (chapter 1), the development of molecular tools for early detection of sub-lethal effects (chapter 2) and the development of protocols to access lethal and sub-lethal effects on other pollinator taxa (Diptera; chapter 3).

Trypanosoma Cruzi Strains From Triatomine Collected In Bahia And Rio Grande Do Sul, Brazil.

Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.

Developmental Rate Of Immatures Of Two Fly Species Of Forensic Importance: Sarcophaga (liopygia) Ruficornis And Microcerella Halli (diptera: Sarcophagidae).

Since insect species are poikilothermic organisms, they generally exhibit different growth patterns depending on the temperature at which they develop. This factor is important in forensic entomology, especially for estimating postmortem interval (PMI) when it is based on the developmental time of the insects reared in decomposing bodies. This study aimed to estimate the rates of development, viability, and survival of immatures of Sarcophaga (Liopygia) ruficornis (Fabricius 1794) and Microcerella halli (Engel 1931) (Diptera: Sarcophagidae) reared in different temperatures: 10, 15, 20, 25, 30, and 35 ± 1 °C. Bovine raw ground meat was offered as food for all experimental groups, each consisting of four replicates, in the proportion of 2 g/larva. To measure the evolution of growth, ten specimens of each group were randomly chosen and weighed every 12 h, from initial feeding larva to pupae, and then discarded. Considering the records of weight gain, survival rates, and stability of growth rates, the range of optimum temperature for the development of S. (L.) ruficornis is between 20 and 35 °C, and that of M. halli is between 20 and 25 °C. For both species, the longest times of development were in the lowest temperatures. The survival rate at extreme temperatures (10 and 35 °C) was lower in both species. Biological data such as the ones obtained in this study are of great importance to achieve a more accurate estimate of the PMI.