Araucaria angustifolia (Bert.) O. Kuntze induces oxidative and genotoxic damage in larvae of Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae)

Plant-derived products have been considered as an important alternative to common pesticides. Araucaria angustifolia extract (AAE) contains high levels of polyphenols, which are correlated with mortality in defoliating insects. Therefore, this study aimed to evaluate the effects of AAE treatments on A. gemmatalis larvae. Results showed that AAE was able to induce lipid, protein, and DNA damage in the larvae via oxidative stress. AAE treatment did not induce larvae mortality; however, there was an increase in the number of malformed pupae, along with a decrease in the emergence of the insects. These biological effects may be correlated with the polyphenol content of the AAE.     

Fatal cases of Theileria annulata infection in calves in Portugal associated with neoplastic-like lymphoid cell proliferation

This study was carried out to investigate fifteen cases of acute lethal infection of calves (≤ 4 months of age) by the protozoan parasite Theileria (T.) annulata in the south of Portugal. Calves developed multifocal to coalescent nodular skin lesions, similar to multicentric malignant lymphoma. Infestation with ticks (genus Hyalomma) was intense. Theileria was seen in blood and lymph node smears, and T. annulata infection was confirmed by isolation of schizont-transformed cells and sequencing of hypervariable region 4 of the 18S rRNA gene. At necropsy, hemorrhagic nodules or nodules with a hemorrhagic halo were seen, particularly in the skin, subcutaneous tissue, skeletal and cardiac muscles, pharynx, trachea and intestinal serosa. Histologically, nodules were formed by large, round, lymphoblastoid neoplastic-like cells. Immunohistochemistry (IHC) identified these cells as mostly CD3 positive T lymphocytes and MAC387 positive macrophages. A marker for B lymphocytes (CD79αcy) labeled very few cells. T. annulata infected cells in these nodules were also identified by IHC through the use of two monoclonal antibodies (1C7 and 1C12) which are diagnostic for the parasite. It was concluded that the pathological changes observed in the different organs and tissues were caused by proliferation of schizont-infected macrophages, which subsequently stimulate a severe uncontrolled proliferation of uninfected T lymphocytes.     

Papillary architecture of the Leopardus pardalis tongue

The ocelot (Leopardus pardalis) is a Felidae of wide geographical distribution and food flexibility; therefore, it is essential to understand the morphology of the species. Thus, we aimed to describe its lingual morphology in order to gain information regarding the anatomy of this carnivore's digestive system. The tongues ??were removed for ex situ macroscopic and morphometric analyses, as well as for light microscopy and scanning electron microscopy, of fragments of the different lingual regions. The tongue of L. pardalis had an elongated form that was subdivided into the apex, body and root, in which four papillary types were observed: filiform, fungiform, circumvallate and conical. It presented with a stratified, keratinized squamous epithelium, followed by loose and dense connective tissues, as well as a skeletal striated musculature that comprised most of the organ. In addition, in scanning electron microscopy the filiform papillae showed a complex with multiple layers of keratin with triangular shape projected caudally in oral cavity. The fungiform papillae were distributed among the filiform and showed a rounded shape with some gustatory pores, and are keratinized but in a lower intensity if compared with filiform. The vallate papillae, located in lingual root, showed an oval format, had a deep groove surrounded the papillae and some gustatory pores. The conical papillae are located in lingual root and are similar to the filiform. The tongue of L. pardalis resembles other carnivorous species, mainly among felids. However, it differed in relation to the quantity of vallate papillae and the absence of foliate papillae.     

Methane emission by Nellore cattle subjected to different nutritional plans

The objective was to evaluate the emission of enteric methane by Nellore cattle subjected to different nutritional plans, as well as the intake and digestibility of nutrients from the diets supplied. Forty-seven animals in a confinement system (feedlot) were fed a corn silage-based diet for 35 days. Afterwards, these animals were evaluated in a grazing system during the rainy periods, in Urochloa brizantha cv Marandu paddocks, for 44 days. Chromic oxide was used as external marker to estimate the fecal production of animals. Samples of feces, ingredients, and pasture were collected and sampled for subsequent chemical analyses. The SF₆ tracer gas technique was adopted to quantify the methane gas emitted by the animals. The experimental design was completely randomized, using procedure GLM of software SAS (9.2), including the fixed effects of sex and nutritional plan and the linear effect of the co-variable weights. Means were analyzed by Tukey’s test at 5 % probability. The intakes of total dry matter and organic matter were greater for the animals subjected to the feedlot diet (P?P?P?4/day (104.01 g) by the animals fed the feedlot diet (P?4/CEB) and methane emission per dry matter consumed were lower in relation to the grazing treatment (3.75 vs 4.23 % and 11.67 vs 15.71 g/kg). The better quality of the diet in the feedlot promoted lower energy losses as methane.     

N2O emissions from an irrigated and non‐irrigated organic soil in eastern Canada as influenced by N fertilizer addition

Drainage and cultivation of organic soils often result in large nitrous oxide (N₂O) emissions. The objective of this study was to assess the impacts of nitrogen (N) fertilizer on N₂O emissions from a cultivated organic soil located south of Montréal, QC, Canada, drained in 1930 and used since then for vegetable production. Fluxes of N₂O were measured weekly from May 2004 to November 2005 when snow cover was absent in irrigated and non‐irrigated plots receiving 0, 100 or 150 kg N ha⁻¹ as NH₄NO₃. Soil mineral N content, gas concentrations, temperature, water table height and water content were also measured to help explain variations in N₂O emissions. Annual emissions during the experiment were large, ranging from 3.6 to 40.2 kg N₂O‐N ha⁻¹ year⁻¹. The N₂O emissions were decreased by N fertilizer addition in the non‐irrigated site but not in the irrigated site. The absence of a positive influence of soil mineral N content on N₂O emissions was probably in part because up to 571 kg N ha⁻¹ were mineralized during the snow‐free season. Emissions of N₂O were positively correlated to soil CO₂ emissions and to variables associated with the extent of soil aeration such as soil oxygen concentration, precipitation and soil water table height, thereby indicating that soil moisture/aeration and carbon bioavailability were the main controls of N₂O emission. The large N₂O emissions observed in this study indicate that drained cultivated organic soils in eastern Canada have a potential for N₂O‐N losses similar to, or greater than, organic soils located in northern Europe.     

Assessing genetic diversity in the cassava (Manihot esculenta Crantz) germplasm collection in Brazil using PCR-based markers

Knowledge of the origin, organization and nature of the cassava (Manihot esculenta Crantz) germplasm collection in Brazil is incomplete due to lack of critical information on several aspects of the collection. This study verifies the utility of SSR-primed PCR markers for germplasm assessment and then utilizes these markers as well as RAPD's to characterize the Brazilian collection. We specifically address the following questions: 1)what is the relationship of morphologically closely related species to cultivated cassava? 2) What is the genetic diversity of cultivars within and between different habitats in Brazil? 3) Do agronomic traits and molecular markers reveal the same relationship among cassava accessions? 4) How complete is the Brazilian cassava collection and how well is it represented in the Word Core Collection of cassava, maintained by CIAT? Results of the interspecific studies of cassava and its wild relatives confirms the close relationship of cassava, Manihot esculenta ssp. esculenta to Manihot esculenta ssp. flabellifolia as well identifying several other closely related wild species. Next, PCR-based markers indicate a strong grouping of varieties related to the region of cultivation in Brazil. Moreover, important regions such as Cerrados and Amazon are relatively poorly represented in germplasm collections. Interestingly, the relationships of accessions based on agronomic traits are not fully congruent with relationships revealed with RAPD markers. Finally, the genetic diversity of the Brazilian cassava collection is not fully represented in the Core of the Word Core Collection of CIAT.     

Preventing invasions of Asian longhorn beetle and citrus longhorn beetle: are we on the right track?

Two Asian longhorn beetles, Anoplophora glabripennis and Anoplophora chinensis, are among the most serious alien invasive species attacking forest and urban trees, both in North America and Europe. Major efforts have been put into preventing further entry and establishment of the two species as well as promoting their successful eradication. Here, we review these efforts, their progress and outcome, and scientific advancements in monitoring and control methods. The combined international activities and harmonizing legislative changes in detection and eradication methods have proven worthwhile, with more than 45% of eradication programmes successful in the last 12 years. Some countries were able to completely eradicate all populations and others managed to reduce the area affected. Although the costs of the eradication programmes can be very high, the benefits outweigh inaction. Attempts to eradicate A. chinensis have been more challenging in comparison with those targeting A. glabripennis. For both species, efforts are hampered by the ongoing arrival of new beetles, both from their native regions in Asia and from other invaded regions via bridgehead effects. The methods used for eradication have not changed much during the last decade, and host removal is still the method most commonly used. On the other hand, detection methods have diversified during the last decade with advances in semiochemical research and use of detection dogs. The next decade will determine if eradications continue to be successful, particularly in the case of A. chinensis, which has been targeted in some countries for containment instead of eradication.

     

In vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana Perr.) against gastrointestinal nematodes in goats

The resistance of gastrointestinal nematodes (GINs) of small ruminants to anthelmintics has required the investigation of new alternatives. The aim of the present study was to evaluate the in vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana) (AESW) against GINs in goats and to observe the animals for toxic effects. Thirty animals that were naturally infected with GINs were distributed into three groups: group I, was treated with daily doses of AESW (1.7 g/kg) for eight days; Group II, the positive control, was treated with a single dose of levamisole phosphate (6.3mg/kg); and group III, the negative control, was left untreated. Faecal eggs counts (FECs), coprocultures and post-mortem worm counts were performed to assess the efficacy of the treatments. Clinical and laboratory analyses were performed to evaluate any toxic effects associated with the treatment. In the goats in groups I and II, a significant reduction (p<0.05) of the number of eggs and infective larvae (L(3)) was observed. The maximum reductions of the FECs were 50.3% and 93.6% for groups I and II, respectively, whereas the percent reductions of the total number of L(3) larvae were 80% (group I) and 85.6% (group II). There was no difference between groups I and III with respect to worm burden, and the percent reductions were 28.8% and 63.4% for Oesophagostomum columbianum and Trichostrongylus colubriformis, respectively. No reduction was detected for the Haemonchus contortus. The positive control group demonstrated a 74% reduction of the parasites that were recovered from the digestive tract. There were no changes in clinical and haematological parameters. The levels of serum urea and creatinine were higher in group I, but remained within the normal range. At necropsy, pale mucous membranes, abomasitis and enteritis were associated with parasitism. In addition, a histological analysis of the liver and kidney did not reveal any changes suggestive of toxicity. A chemical analysis of the AESW demonstrated the presence of saponins, which after acid-hydrolyses reaction, gave the sapogenins hecogenin and tigogenin. The AESW had a low efficacy for the parasitic stages and was moderately effective against eggs and free-living stages. Furthermore, the treatment was not toxic to the goats.