RESUMO
Although glyphosate is widely used for weed pest control, it might have negative side effects on natural enemies. Wolf spiders are one of the most representative predators found on soybean crops in Uruguay, preying on a wide variety of potential pests. However, the sublethal effects that pesticides might have on this group have been poorly explored for South American species. Herein, we explored the sublethal effects of glyphosate on the functional response of the wolf spider Hogna cf. bivittata against three potential pest insects, namely ant (Acromyrmex sp.), caterpillar (Anticarsia gemmatalis), and cricket (Miogryllus sp.). We contaminated residually adult females of the species Hogna cf. bivittata with glyphosate (Roundup®) and compared their functional response against non-contaminated spiders. We did not observe any mortality during the study. We found that overall Hogna cf. bivittata showed a functional response type II against crickets and caterpillars but no functional response to ants. Contaminated spiders killed less ants and caterpillars in comparison to the control group, probably as a consequence of the irritating effects of glyphosate. We did not observe differences in functional response to crickets at the evaluated densities, probably as a consequence of the low capture rate against this prey. Although glyphosate does not specifically target spiders, it might have negative sublethal effects on native predators such as Hogna cf. bivittata. Further studies should explore effect of glyphosate on other native predators from South American crops.
Assuntos
Glicina/análogos & derivados , Praguicidas/toxicidade , Aranhas/efeitos dos fármacos , Animais , Formigas , Produtos Agrícolas , Feminino , Glicina/toxicidade , Gryllidae , Mariposas , Comportamento Predatório/efeitos dos fármacos , Uruguai , GlifosatoRESUMO
The avulsion of nerve roots of the brachial plexus that is commonly seen in motorcycle accidents is a type of neuropathy due to deafferentation. This type of pain is clinically challenging since therapeutical protocols fail or have severe side effects. Thus, it is proposed to evaluate the antinociceptive activity of the recombinant CTK 01512-2 peptide that is derived from the venom of the Phoneutria nigriventer spider, as a future new therapeutical option. The neuropathic pain was surgically induced by avulsion of the upper brachial plexus trunk in groups of male Wistar rats and after 17â¯days, they were treated intrathecally with morphine, ziconotide, and CTK 01512-2. Behavioral tests were performed to evaluate mechanical and thermal hyperalgesia, cold allodynia, the functional activity of the front paw, and exploratory locomotion after the treatments. The peripheral blood samples were collected 6â¯h after the treatments and a comet assay was performed. The spinal cord was removed for the lipoperoxidation dosing of the membranes. The cerebrospinal fluid was analyzed for the dosage of glutamate. The recombinant peptide showed an antinociceptive effect when compared to the other drugs, without affecting the locomotor activity of the animals. Mechanical and thermal hyperalgesia, as well as cold allodynia, were reduced in the first hours of treatment. The levels of glutamate and the damage by membrane lipoperoxidation were shown to be improved, and genotoxicity was not demonstrated. In a scenario of therapeutical failures in the treatment of this type of pain, CTK 01512-2 was shown as a new effective alternative protocol. However, further testing is required to determine pharmacokinetics.
Assuntos
Analgésicos/farmacologia , Aranhas/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Peçonhas/metabolismo , Animais , Diferenciação Celular , Masculino , Morfina/farmacologia , Nociceptividade/efeitos dos fármacos , Peptídeos/farmacologia , Ratos Wistar , Aranhas/metabolismo , Medula Espinal/citologiaRESUMO
Tarantulas are a commonly kept species that are occasionally presented to veterinarians in exotic practice. A recent study on Grammastola rosea hemolymph biochemistry has been performed with nonanesthetized adult theraphosids. The objective of this study was to produce reference intervals for biochemistry biomarkers in hemolymph of chemically restrained G. rosea for use diagnostically by exotic veterinarians. Cardiac hemolymph collection was performed on 20 subadult tarantulas under general anesthesia with isoflurane. Samples were processed by a commercial laboratory. Statistics performed on the data include outlier exclusion, descriptive statistics, normality tests, and Pearson correlations. Reference intervals were made for total protein, creatine kinase (CK), aspartate aminotransferase (AST), glucose, uric acid (UA), calcium, and phosphorus. No cortisol was detected. The majority of the intervals produced were normally distributed with the exceptions of UA, phosphorus, and CK. Pearson correlation tests found several significant (P = <0.05) correlations between variables. The majority of the data displayed a normal distribution, unlike the previous study, with a greater number of replicates. The total protein, glucose, UA, calcium, and AST values generated were similar to those reported in the previous study. Conversely several variables such as phosphorus, CK, and albumin were not consistent with those previously reported. Evidence is presented for a lack of albumin, CK, and AST in Arachnida and thus previous data for these proteins is likely to be artifactual.
Assuntos
Anestésicos Gerais/administração & dosagem , Hemolinfa/química , Isoflurano/administração & dosagem , Aranhas/química , Anestesia Geral/veterinária , Animais , Análise Química do Sangue/veterinária , Valores de Referência , Aranhas/efeitos dos fármacosRESUMO
The aim of this work was to determine the efficiency and feasibility of two different watermelon pest control systems on pest infestations, natural enemies, and on the productivity and sustainability of watermelon cropping. Two independent experiments were carried out during the dry season of 2011. Both experiments were carried out using a randomized block experimental design, with three treatments; weekly application of pesticide (WAP), integrated pest management (IPM), and nonpesticide application (control); and four replicates. Arthropods sampling was performed every 2 d by direct counting at five randomly selected points in each plot. Samples were taken by beating the leaves from the apical portion of the plant against a white plastic tray. Arthropods that moved along the soil surface were sampled weekly using pitfall traps. Both WAP and IPM treatments negatively affected the arthropod population. We conclude that IPM is an attractive strategy for watermelon cropping both economically and environmentally because it provides the grower with an option to lower production cost, achieves the same production, and there is less need for pesticide application when compared with the prophylactic control treatment when pesticides are applied on a weekly basis. This has not been reported for watermelon before.
Assuntos
Citrullus/crescimento & desenvolvimento , Insetos/efeitos dos fármacos , Inseticidas/farmacologia , Inseticidas/toxicidade , Controle de Pragas/métodos , Aranhas/efeitos dos fármacos , Animais , Brasil , Controle de Pragas/economiaRESUMO
Parents defend their young in many ways, including provisioning chemical defences. Recent work in a poison frog system offers the first example of an animal that provisions its young with alkaloids after hatching or birth rather than before. But it is not yet known whether maternally derived alkaloids are an effective defence against offspring predators. We identified the predators of Oophaga pumilio tadpoles and conducted laboratory and field choice tests to determine whether predators are deterred by alkaloids in tadpoles. We found that snakes, spiders and beetle larvae are common predators of O. pumilio tadpoles. Snakes were not deterred by alkaloids in tadpoles. However, spiders were less likely to consume mother-fed O. pumilio tadpoles than either alkaloid-free tadpoles of the red-eyed treefrog, Agalychnis callidryas, or alkaloid-free O. pumilio tadpoles that had been hand-fed with A. callidryas eggs. Thus, maternally derived alkaloids reduce the risk of predation for tadpoles, but only against some predators.
Assuntos
Alcaloides/toxicidade , Anuros , Comportamento Materno , Comportamento Predatório/efeitos dos fármacos , Aranhas/efeitos dos fármacos , Animais , Besouros , Feminino , Larva , SerpentesRESUMO
OBJECTIVE: To determine the safety, efficacy, and effects on hemolymph gas analysis variables of sevoflurane anesthesia in Chilean rose tarantulas (Grammostola rosea). ANIMALS: 12 subadult Chilean rose tarantulas of unknown sex. PROCEDURES: Spiders were anesthetized in a custom chamber with sevoflurane (5% in oxygen [1.0 L/min]), then allowed to recover in 100% oxygen. Righting reflex was evaluated every 3 minutes during anesthesia to determine time to anesthetic induction and recovery. Hemolymph samples were collected from an intracardiac location prior to and after induction of anesthesia and evaluated to determine various gas analysis variables. RESULTS: Mean ± SD induction and recovery times were 16 ± 5.91 minutes and 29 ± 21.34 minutes, respectively. Significant differences were detected for Po2, base excess, and glucose and ionized magnesium concentrations between hemolymph samples obtained before anesthesia and those obtained after induction of anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE-Results of this study suggested that the use of sevoflurane as an anesthetic agent for Chilean rose tarantulas was safe and effective. Various hemolymph sample gas analysis values changed during anesthesia.
Assuntos
Anestésicos Inalatórios/farmacologia , Hemolinfa/efeitos dos fármacos , Éteres Metílicos/farmacologia , Reflexo de Endireitamento/efeitos dos fármacos , Aranhas/efeitos dos fármacos , Análise de Variância , Período de Recuperação da Anestesia , Animais , Gasometria , Glicemia , Hemolinfa/química , Magnésio/sangue , Masculino , Reflexo de Endireitamento/fisiologia , Sevoflurano , Aranhas/fisiologiaRESUMO
This study evaluated the use of the injectable anesthetic, alphaxalone, as a single agent and in combination with ketamine, xylazine, and morphine in the Chilean rose tarantula, Grammostola rosea. Between two and four animals were evaluated for each anesthetic protocol, and two unanesthetized animals were evaluated for comparative purposes. Anesthetic duration, depth, and quality were assessed by scoring responses to tactile and trichobothria stimulation, muscle tone, purposeful movement, righting response, and heart rate throughout each anesthetic event. Alphaxalone administered into the dorsal opisthosoma in the location of the heart at 200 mg/kg produced moderate anesthetic effect with a median duration of 28 min (n = 3; range 25-50). A combination of 200 mg/kg of alphaxalone and 20 mg/kg of ketamine induced a deep anesthetic state with a median anesthetic duration of 27 min (n = 4; range 16-42). The combination of 200 mg/kg of alphaxalone and 20 mg/kg of xylazine produced deep anesthesia with a median duration of 70 min (n = 4; range 37-207). Morphine administered at 5 mg/kg 30 min prior to injection with 200 mg/kg alphaxalone had anesthetic durations of 9 and 30 min (n = 2). Heartbeats could not be detected for periods of 7-27 min following anesthetic induction for the majority of animals receiving the alphaxalone/ketamine and alphaxalone/xylazine anesthetic combinations. No mortality was associated with any of the anesthetic protocols used; however, ambient temperature and ecdysis were identified as important factors that may alter response to anesthetics in these animals.
Assuntos
Ketamina/farmacologia , Morfina/farmacologia , Pregnanodionas/farmacologia , Aranhas/efeitos dos fármacos , Xilazina/farmacologia , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/farmacologia , Anestésicos/administração & dosagem , Anestésicos/farmacologia , Animais , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/farmacologia , Ketamina/administração & dosagem , Morfina/administração & dosagem , Projetos Piloto , Pregnanodionas/administração & dosagem , Xilazina/administração & dosagemRESUMO
Soybean pest control in Argentina is done just by chemical control using broad-spectrum pesticides. Alpaida veniliae (Araneae, Araneidae) is one of the most abundant spider species of the orb web weaver guild in soybean, and it is considered a very important polyphagous predator, attacking different insects' families. The objective of this study was to determine if neurotoxic insecticides commonly used in soybean crops and a new active ingredient registered in Argentina (spinosad) adversely affected survival, prey consumption, mating behaviour, web building and reproductive capacity of A. veniliae females, under standard laboratory conditions. Spinosad was the most harmful insecticide due to high acute toxicity, even at lower concentrations than those registered for its field use and for its sublethal effects also. Cypermethrin caused several sublethal effects although its acute toxicity on spider was lower than other insecticides. It reduced prey consumption, affected web building, caused abnormalities in eggs sacs and decreased drastically the fecundity and fertility at sublethal concentrations. Endosulfan did not reduce prey consumption but it affected web building, caused abnormalities in eggs sacs and egg masses, and decreased the fecundity and fertility. Spinosad was also the compound with the most drastic effect on web building, it did not reduce prey consumption and fecundity, but fertility was reduced and abnormalities in egg sacs and egg masses were observed. The use of these insecticides in IPM programs according to their potential toxicity on spider communities is discussed.
Assuntos
Inseticidas/toxicidade , Neurotoxinas/toxicidade , Aranhas/efeitos dos fármacos , Animais , Argentina , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Endossulfano/toxicidade , Feminino , Fertilidade/efeitos dos fármacos , Macrolídeos/toxicidade , Masculino , Óvulo/efeitos dos fármacos , Piretrinas/toxicidade , Comportamento Sexual Animal/efeitos dos fármacos , Aranhas/fisiologia , Fatores de TempoRESUMO
This study investigated the use of two anesthetic agents, isoflurane and carbon dioxide, in Chilean rose tarantulas (Grammostola rosea). We compared the onset, duration of anesthesia, and recovery time with both gases, and made observations regarding the effects of the anesthetic protocols. Subjectively, episodes for the isoflurane animals were uneventful. The spiders were calm throughout and did not respond adversely to gas exposure. Conversely, animals anesthetized with carbon dioxide experienced violent inductions and recoveries; the tarantulas appeared agitated when the carbon dioxide flow began. Seizure-like activity and defecation would frequently be noted prior to induction with carbon dioxide. Neither isoflurane nor carbon dioxide seemed to have any clinically apparent short- or long-term impact. The animals were all normal for at least 1-year postexperiment. Future studies should focus on defining the impact, if any, that these anesthetic agents have on the health of invertebrate species.
Assuntos
Anestesia/métodos , Dióxido de Carbono/farmacologia , Isoflurano/farmacologia , Aranhas/efeitos dos fármacos , AnimaisRESUMO
Intensive use of pesticides is common and increasing despite a growing and historically well documented awareness of the costs and hazards. The benefits from pesticides of increased yields from sufficient pest control may be outweighed by developed resistance in pests and killing of beneficial natural enemies. Other negative effects are human health problems and lower prices because of consumers' desire to buy organic products. Few studies have examined these trade-offs in the field. Here, we demonstrate that Nicaraguan cabbage (Brassica spp.) farmers may suffer economically by using insecticides as they get more damage by the main pest diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), at the same time as they spend economic resources on insecticides. Replicated similarly sized cabbage fields cultivated in a standardized manner were either treated with insecticides according common practice or not treated with insecticides over two seasons. Fields treated with insecticides suffered, compared with nontreated fields, equal or, at least in some periods of the seasons, higher diamondback moth pest attacks. These fields also had increased leaf damage on the harvested cabbage heads. Weight and size of the heads were not affected. The farmers received the same price on the local market irrespective of insecticide use. Rates of parasitized diamondback moth were consistently lower in the treated fields. Negative effects of using insecticides against diamondback moth were found for the density of parasitoids and generalist predatory wasps, and tended to affect spiders negatively. The observed increased leaf damages in insecticide-treated fields may be a combined consequence of insecticide resistance in the pest, and of lower predation and parasitization rates from naturally occurring predators that are suppressed by the insecticide applications. The results indicate biological control as a viable and economic alternative pest management strategy, something that may be particularly relevant for the production of cash crops in tropical countries where insecticide use is heavy and possibly increasing.