Effects of sheep manure in agricultural soils on the behavior of Folsomia candida and initial growth and development of Avena sativa

The aim of this study was to evaluate the effects of sheep manure in agricultural soils on the behavior of Folsomia candida and initial growth and development of Avena sativa. For this, an Oxisol was submitted to different doses of sheep manure and was subsequently evaluated for Folsomia candida survival and avoidance behavior through standardized ecotoxicological assays, the initial performance of oats by germination test and the soil basal respiration rate by respirometry methodology. There was an increase in the basal respiration rate of the soil by the application of sheep manure and this was consistent with the increase of the doses. The survival rate and avoidance behavior of springtails were not altered and there was no change in the initial performance of oats, indicating that this manure can be used for organic fertilization of soils with low soil pollutant potential.

Impacts on reproduction of Enchytraeus crypticus in fertilized soils with chicken litter treated with synthetic and natural insecticide

Poultry litter is used as a fertilizer due to the high concentration of nutrients. However, this material receives application of medicines, whether they are used to treat animals or the litter itself. Thus, the objective was to evaluate if the application in soils of poultry litter doses treated with two insecticides (cypermethrin and cinnamon oil) used to control of the Alphitobius diaperinus, affect the reproduction of Enchytraeus crypticus, and the insecticides effects over time, trough of ecotoxicological tests using soils with different textural classes an Entisol and an Oxisol. In the Oxisol the application of poultry litter stimulated the E. crypticus reproduction regardless of the insecticide and the collection time. In Entisol the poultry litter showed a toxicity at 10 t ha^-1 when treated with cypermethrin and at 30 t ha^-1 with cinnamon oil. Entisol results show that cypermethrin affects non-target edaphic organisms soon after spraying, but over time has reduced toxicity unlike cinnamon oil.

Increasing level of liquid pig manure reduces Eisenia andrei and Enchytraeus crypticus reproduction in subtropical soils

Wastes generated in pig production are widely used as agricultural fertilizers. Nevertheless, such form of disposal supplies large amounts of waste in soils annually and can cause environmental pollution. The ecological risk of this practice to soil organisms has received little attention. Ecotoxicological tests are used to evaluate the toxicity of contaminants added to the soil biota. The aimed to evaluate the effect of liquid pig manure (LPM) on the reproduction of Eisenia andrei and Enchytraeus crypticus when applied in natural soils. LPM doses caused effects on earthworm reproduction in both soils, with EC₅₀ of 112 and 150 m³ ha⁻¹ in the Entisol and Nitosol, respectively. On enchytraeids, LPM had bigger effects, leading to EC₅₀ of 17.7 and 45.0 m³ ha⁻¹ in the Entisol and Nitosol, respectively. The results emphasize the importance to consider the ecological risks of LPM of conducting studies with natural soils and edaphic fauna as indicators.

Eprinomectin antiparasitic affects survival, reproduction and behavior of Folsomia candida biomarker, and its toxicity depends on the type of soil

The objective of this study was to evaluate the toxicity of the antiparasitic agent eprinomectin in two subtropical soils, using ecotoxicological lethality, reproduction and avoidance behavior tests with springtails (Folsomia candida). Eprinomectin concentrations were 0 (control), 0.5, 1, 2, 4, 8, 12, 16 and 20 mg kg^-1 of dry soil combined with either Entisol or Oxisol soils. Statistically significant toxic effects of eprinomectin on springtails were observed in both soils. Eprinomectin was lethal starting at 8 mg kg^-1 of dry soil in Entisol, and 20 mg kg^-1 of dry soil in Oxisol, with effects less than 50% at lethal concentrations. Reductions in the reproduction rate of the springtails were also observed starting at 8 mg kg^-1 of dry soil in Entisol, and 0.5 mg kg^-1 of dry soil in Oxisol. EC_repr50 value calculated for Entisol was 4.38 ± 0.62 mg kg^-1 of dry soil; for Oxisol the EC_repr50 was above the highest tested concentration. For avoidance behavior, the effect occurred from 0.5 mg kg^-1 of dry soil for both soils. In Entisol, all concentrations caused avoidance of more than 95%, and in Oxisol the EC_avoi50 value was 1.33 ± 0.83 mg kg^-1 of dry soil. We conclude that eprinomectin affected survival, reproduction and caused avoidance behavior of F. candida in both soils. The toxic effects were greater as the concentration in the soils increased. The effects in Oxisol were less intense than those in Entisol with respect to the affected springtails. This discrepancy may be attributed to the different physicochemical characteristics of the soils that determine the retention capacity for eprinomectin; in particular, there are greater contents of clay, organic matter and cation exchange capacity in Oxisol.

Fish exposed to water contaminated with eprinomectin show inhibition of the activities of AChE and Na+/K+-ATPase in the brain, and changes in natural behavior

The objective of this study was to evaluate whether antiparasitic eprinomectin may be an environmental contaminant in water compartment in low concentrations, negatively affecting neurotransmission and, consequently, the natural behavior of the jundiá (Rhamdia quelen). Fish were randomly allocated in tanks and exposed for 24 and 48 h to eprinomectin concentrations in water [0.0 (Control), 1.124 (T1), 1.809 (T2) and 3.976 (T3) μg L^-1], followed by 48 h of recovery in eprinomectin-free water, in order to evaluate the behavioral parameters, levels of reactive oxygen species (ROS) in the brain, as well as cerebral enzymatic activities of acetylcholinesterase (AChE) and of the sodium-potassium ATPase pump (Na⁺/K⁺-ATPase). Especially at the two highest concentrations of eprinomectin (T2 and T3), the fish showed alterations in natural behavior, particularly hyperlocomotion and longer time on the surface. Furthermore, at these same concentrations, cerebral ROS levels increased and cerebral AChE activity decreased. At the highest concentration (T3) cerebral Na⁺/K⁺-ATPase activity was reduced. Increased ROS and impairment of AChE and Na⁺/K⁺-ATPase enzymes in the brain may have contributed directly to behavioral changes, due to neuronal damage and synapse impairment. Even after 48 h in water without eprinomectin, behavioral changes and neurotoxic effects were observed in fish, suggesting residual effects of the antiparasitic. In conclusion, eprinomectin even in low concentrations may be a hazardous environmental contaminant for aquatic organisms, as it causes brain damage and affects the natural behavior of fish.

Evaluation of cytotoxicity, genotoxicity and ecotoxicity of nanoemulsions containing Mancozeb and Eugenol

Mancozeb is a fungicide widely used in agriculture, mostly against the pathogen Glomerella cingulata responsible for the rot of ripe grape, but presents high toxicity. Strategies are sought to reduce the toxicity of this fungicide and alternative treatments are welcome. An alternative could be the use of clove oil, which has Eugenol as its major compound, and has antifungal potential against G. cingulata, however, Eugenol is susceptible to degradation processes which may compromise its efficacy. The nanoencapsulation of Mancozeb and Eugenol is a possible strategy to overcome the limitations of toxicity, solubility and instability of these compounds. Therefore, the objective of this study is to develop nanoemulsions containing Mancozeb (0.1 mg/mL) and Eugenol (33 mg/mL), isolated or associated, and evaluate the safety of these formulations through cytotoxicity, genotoxicity and ecotoxicity tests. Nanoemulsions were developed by the spontaneous emulsification method, cytotoxicity and genotoxicity were evaluated in healthy human cells through MTT, Dichlorofluorescein diacetate and Picogreen tests, and ecotoxicity assessment was carried out using the chronic toxicity test in springtails. After preparation, the physicochemical characterization of the nanoemulsions were performed which presented mean particle size between 200 and 300 nm, polydispersity index less than 0.3, negative zeta potential and acid pH. The nanoencapsulation was able to avoid the reduction of the cell viability caused by Mancozeb, while Eugenol was shown to be safe for cell use in both free and nanostructured forms, however the association of the two active compounds showed toxicity in the higher doses of Mancozeb. In the ecotoxicity tests, both free Mancozeb and Eugenol forms presented high toxic potential for soil, whereas the nanoencapsulation of these compounds did not cause a reduction in number of springtails. Therefore, from the tests performed, it was possible to observe that nanoencapsulation of Mancozeb and Eugenol is a safe alternative for the application of these compounds mainly in agriculture.

Ecotoxicological assessment of Fluazuron: effects on Folsomia candida and Eisenia andrei

The cattle production in Brazil has increased considerably in the last years, mainly due to the control of parasite infestation of the animals, which cause loss of productivity to the sector. Fluazuron is an active ingredient (a.i.) of the benzoylurea class used to control ticks in cattle. As this a.i. has been found unchanged in animal feces, which may present a risk to edaphic organisms, this study aimed to assess the effects of fluazuron on survival, reproduction, and behavior of the soil invertebrates Folsomia candida and Eisenia andrei, through ecotoxicological assays. We carried out bioassays in a tropical artificial soil (TAS) spiked with increasing doses of the insecticide. Earthworm mortality was found only at the highest tested fluazuron concentration (LOEC = 160 mg a.i. kg^-1 dry soil and NOEC = 80 mg kg^-1), while the reproduction of F. candida and E. andrei was reduced at lower fluazuron concentrations (EC₅₀ = 4.48 mg kg^-1 and EC₅₀ = 20.8 mg kg^-1, respectively). Avoidance behavior was detected for both species at lower concentrations than those that caused impacts on reproduction, indicating that the substance may affect the soil habitat function. Since the possible adverse effects of fluazuron on edaphic fauna are still unknown or neglected, this study also warns about the possible harmful effect of veterinary pharmaceutical products on edaphic fauna.

Disentangling the effects of the aqueous matrix on the potential toxicity of liquid pig manure in sub-tropical soils under semi-field conditions

Inadequate application of liquid pig manure (LPM) may pose risks to the soil due to the potential contaminants that exists, as well as by the large water input that can originate excessive moisture. By using Terrestrial Model Ecosystems, this study aimed to evaluate the effect of application of LPM (82% moisture) using the application rates of 20, 50 and 150 m³ ha^-1 and also of the corresponding amount of water to understand the origin of effects on the soil fauna of two sub-tropical soils. In general, the results obtained for the two soil types indicated that LPM (150 m³ ha^-1) changed the composition of soil fauna, with an increase in the abundance of insect larvae and dipterans, but a decrease in the number of earthworms and enchytraeids. Microbial biomass, soil respiration and the nutrients Mg, K and P increased with the amount of LPM supplied to the soil. When analysing the effects of adding large volumes of water via the LPM, results showed that application did not originate significant effects on the parameters measured. The differences obtained when comparing both treatments were mainly attributed to the organic load brought by the LPM and not to the amount of water without LPM.

Ecotoxicological effects of fipronil, neem cake and neem extract in edaphic organisms from tropical soil

Veterinary medicines are widely applied for the treatment and prevention of animal diseases. Consequently, animal manure contains significant amounts of environmental pollutants that are potential sources of environmental pollution when inappropriately applied in soils. This work aimed to evaluate ecotoxicological effects of doses of commercial fipronil, neem cake and neem extract in the survival and reproduction of earthworms (Eisenia andrei), enchytraeidae (Enchytraeus crypticus) and springtails (Folsomia candida) in Oxisol and tropical artificial soil (TAS). Applications of fipronil, neem cake and extract in soil were carried out according to standardized ISO methodologies by using a random experimental design with five replicates. Toxic effects of fipronil for springtails in Oxisol and TAS were observed with LC₅₀ of 0.26 mg kg^-1 (0.18-0.35 mg kg^-1) and 0.29 mg kg^-1 (0.22-0.37 mg kg^-1), respectively. It was not observed significant toxic effects of fipronil for earthworms and enchytraeidae in both soils. However, significant amounts of juvenile earthworm and adult enchytraeidae decreased in fipronil doses higher than 10 mg kg^-1. Neem cake and extract were not toxic for earthworms and enchytraeidae but, significant amounts of juvenile springtails decreased in neem cake doses from 500 to 1000 mg kg^-1. It can be concluded that the use of veterinary medicines containing synthetic compounds for preventing diseases in animals needs to be controlled to avoid environmental pollution after applying manure in soil. Veterinary medicines containing natural compounds as neem cake and extract are eco-friendly and could be efficiently applied in soil in a sustainable way.

Cinnamomum zeylanicum Essential Oil Reduces Infestation by Alphitobius diaperinus in Poultry Litter

 Background: Even though insecticides are managed and the period of sanitary emptiness in poultry is respected, the elimination of Alphitobius diaperinus may not be successful. The use of essential oils of plant origin presents as a good alternative in the substitution of insecticides with synthetic molecules, since they are easy to obtain, with rapid degradation and without risk of residues for non-target organisms. The main objective of the present study was to examine whether Cinnamomum zeylanicum oil reduces Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) infestations under experimental conditions, without causing toxicity to broilers chicks exposed to treated litter.Materials, Methods & Results: The experimental design was completely randomized, with four replications per treatment. The treatments were as follows: solvent control using the diluent Dimethyl Sulfoxide 5% (oil diluent); chemical control using 5 g/m² cypermethrin; one spray of C. zeylanicum 5% oil; and two sprays of C. zeylanicum 5% oil. Each experimental unit was infested with 150 lesser mealworm adults. At 15 days of the broiler chick’s life, blood was collected for biochemi­cal analysis (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumin, globulin, triglycerides and uric acid), and liver fragments were isolated for histopathological analysis. Using TupeTrap devices, we counted lesser mealworm 40 days after treatment. The treatments did not alter biochemical variables, and did not cause histopathological lesions in liver. The treatments with C. zeylanicum 5% oil with one and two sprays efficiently reduced lesser mealworm infestation compared with solvent control. Cypermethrin treatment had no effect.Discussion: Many of the commercial products present low effectiveness in the control of A. diaperinus, since the target organisms develop resistance to the product. In the present study, we used a higher cypermethrin dose than that recom­mended by the manufacturer, in order to increase efficacy in the face of possible resistance. Even so, cypermethrin did not efficiently control the organism. The effectiveness of the essential oil of C. zeylanicum tested can be attributed to the compounds found in greater quantity in the oil composition, such as cinnamaldehyde (41.27%), linalool (13.05%) and methyl eugenol (10.87%), characterized as responsible for the action of oil repellency. Monoterpenoid compounds found in essential oils extracted from plants have insecticidal action acting on the central nervous system of insects, which impairs their development, being characterized as neurotoxic compounds. The results found with the essential oil of C. zeylanicum are of great importance, since the control of A. diaperinus is not efficient because this organism has behavior that favors reinfestation in the poultry houses, such as shelter in cracks, in the draperies, below the feeders and in the soil. The biochemical analyzes of the blood can as important tools to assist in the monitoring of broilers health, in the diagnosis and treatment of diseases, and therefore the results presented are of great importance since they assist in the search for alternative methods for the control of A. diaperinus, where we can affirm that the essential oil of C. zeylanicum does not cause toxicity to broilers. Based on these results we can affirm that essential oil of Cinnamomum zeylanicum, 5%, is an effective substitute for existing commercially-available insecticides.Keywords: alternative control, cinnamon oil, insecticide, lesser mealworm.

Cinnamomum zeylanicum Essential Oil Reduces Infestation by Alphitobius diaperinus in Poultry Litter

Background: Even though insecticides are managed and the period of sanitary emptiness in poultry is respected, the elimination of Alphitobius diaperinus may not be successful. The use of essential oils of plant origin presents as a good alternative in the substitution of insecticides with synthetic molecules, since they are easy to obtain, with rapid degradationand without risk of residues for non-target organisms. The main objective of the present study was to examine whether Cinnamomum zeylanicum oil reduces Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) infestations under experimental conditions, without causing toxicity to broilers chicks exposed to treated litter.Materials, Methods & Results: The experimental design was completely randomized, with four replications per treatment. The treatments were as follows: solvent control using the diluent Dimethyl Sulfoxide 5% (oil diluent); chemical control using 5 g/m² cypermethrin; one spray of C. zeylanicum 5% oil; and two sprays of C. zeylanicum 5% oil. Each experimental unit was infested with 150 lesser mealworm adults. At 15 days of the broiler chick’s life, blood was collected for biochemical analysis (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumin, globulin, triglycerides and uric acid), and liver fragments were isolated for histopathological analysis. Using TupeTrap devices, we counted lesser mealworm 40 days after treatment. The treatments did not alter biochemical variables, and did not causehistopathological lesions in liver. The treatments with C. zeylanicum 5% oil with one and two sprays efficiently reduced lesser mealworm infestation compared with solvent control. Cypermethrin treatment had no effect.Discussion: Many of the commercial products present low effectiveness in the control of A. diaperinus, since the target organisms develop resistance to the product. In the present study, we used a higher cypermethrin dose than that recommended by the manufacturer, in order to increase efficacy in the face of possible resistance. Even so, cypermethrin did not efficiently control the organism. The effectiveness of the essential oil of C. zeylanicum tested can be attributed to the compounds found in greater quantity in the oil composition, such as cinnamaldehyde (41.27%), linalool (13.05%) and methyl eugenol (10.87%), characterized as responsible for the action of oil repellency. Monoterpenoid compounds found in essential oils extracted from plants have insecticidal action acting on the central nervous system of insects, which impairs their development, being characterized as neurotoxic compounds. The results found with the essential oil of C. zeylanicum are of great importance, since the control of A. diaperinus is not efficient because this organism has behavior that favors reinfestation in the poultry houses, such as shelter in cracks, in the draperies, below the feeders and in the soil. The biochemical analyzes of the blood can as important tools to assist in the monitoring of broilers health, in the diagnosis and treatment of diseases, and therefore the results presented are of great importance since they assist in the search for alternative methods for the control of A. diaperinus, where we can affirm that the essential oil of C. zeylanicum does not cause toxicity to broilers. Based on these results we can affirm that essential oil of Cinnamomum zeylanicum, 5%, is an effective substitute for existing commercially-available insecticides.Keywords: alternative control, cinnamon oil, insecticide, lesser mealworm.

Repellent Effects of Andiroba and Copaiba Oils against Musca domestica (Common House Fly) and Ecotoxicological Effects on the Environment

Background: The main challenge in raising cattle in Brazil is related to ectoparasites, that cause negative effects on milk and meat production, and in severe cases, animal death. Sheds known as crèches attracts large number insects mainly due to milk residues in the environment. The housefly is a major problem due to act as vectors of many other diseases, and so there is the possibility of control of infestations with natural products. Andiroba and copaiba oils may act as natural biocides, there are only a few studies on their effect on biological soil parameters. Therefore, this study aimed to evaluate the repellent effect of andiroba and copaiba oils against flies and on biological soil parameters.Materials, Methods & Results: The repellency effect of oils of andiroba and copaiba was tested at a concentration of 5% in lambs shed maternity, containing 64 bays (1.8 m2). It was sprayed 30 mL per pen, where they were housed five lambs each. Pre-treatment counts were taken before the treatment (mean 46 per pen after Musca domestica), and post-treatment count was made on 2, 24 and 48 h. The data collected at 2 and 24 h was evaluated and the number of flies was reduced significantly (P < 0.001) in the pens treated with oil of copaiba and andiroba compared to control (untreated) pen. After 48 h, no difference was observed between treatments in relation to fly numbers (P > 0.05). Ecotoxicological test using increasing concentrations in the soil (0, 1, 5, 10, 25, 50, and 100 mg/kg) regarding changes in basal respiration (C-CO2), and survival and reproduction of springtails (Folsomia candida). It was observed an increased amount of mineralized C-CO2 until the day 10 of incubation for both oils without inhibition of the microbial respiratory process in any dose. The copaiba oil showed higher amounts of accumulated C-CO2 compared to andiroba oil in all studied concentrations (P < 0.05). In tests with mesofauna organisms, none of the evaluated concentrations of the two oils showed no negative effect on the survival of springtails (P > 0.05), the same was observed for the reproduction results, where there was no reduction in the number of juveniles (P > 0.05).Discussion: According literature, andiroba and copaiba oils have repellent effect against domestic fly when sprayed onto infected cow’s horn fly, similar results also were reported in vitro tests against M. domestica larvae using andiroba oil and noted 80% larval mortality. The use of natural products in disease control is growing, but its impacts on the environment are not known, so in addition to suggesting therapies it is important to be concerned with ecotoxicological tests. Researchers showed an effect of Eucalyptus globulus essential oil on F. candida and reported 76% reduction in its survival rate at concentration of 60 mg/kg soil.  Basal soil respiration is a sensitive indicator that quickly reveals changes in the environmental conditions that affect microbial activity, and the data presented herein reveal an increase in the respiration of microorganisms depending on the amount of oil added to the soil.  The essential oils of copaiba and andiroba have repellent effect against Musca domestica, and did not show any toxicity to inhibit microbial activity in the soil. In addition, the presence of the oils in the soil did not affect the survival and reproduction of springtails Folsomia candida.