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1.
Braz. j. biol ; 82: e238763, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1180734

RESUMO

Abstract We report the discovery that the earwig predator Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) feed on Puccinia polysora Underw uredospore, the causal agent of Southern Rust of Corn (SRC), which is a primary disease affecting the maize crop in Brazil. We performed experiments in laboratory and greenhouse to test the effect of D. luteipes (1st/2nd and 3rd/4th instars, and adults) fungivory on the P. polysora uredospore concentration. All trials showed a significant reduction of the initial concentration of uredospore. There was a reduction in uredospore concentration with increase in number of D. luteipes feeding on them. We also tested the uredospore consumption by quantifying its percentage in the feces of D. luteipes. Nymphs of the 2nd, 4th instar and adults fed 88%, 85%, and 83.8% of the uredospore, respectively. For nymphs of the 3rd instar, the percentage of uredospore consumption (75.6%) was statistically significant compared with the other groups. In greenhouse experiment, at twenty-eight days after plant inoculation with 9.9 x 104 uredospores, the percentage of uredospore consumption was 81.7%. Our results confirmed the fungivory of D. luteipes on P. polysora uredospore. This is the first report of D. luteipes fungivory, which may play an important role in the biological control of P. polysora in corn.


Resumo Relatamos a descoberta de que o predador Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) se alimenta de uredosporos de Puccinia polysora Underw, o agente causal da ferrugem polisora que é uma doença primária que afeta a cultura do milho no Brasil. Realizamos experimentos em laboratório e em casa de vegetação para testar o efeito da fungivoria de D. luteipes (1º/2º e 3º/4º iìstares e adultos) sobre a concentração de uredosporos de P. polysora. Todos os ensaios mostraram uma redução significativa da concentração inicial de uredosporos. Houve uma redução na concentração de uredosporos com o aumento do número de D. luteipes alimentando-se deles. Também testamos o consumo de uredosporos quantificando sua porcentagem nas fezes de D. luteipes. Ninfas do 2º e 4º ínstar, assim como adultos, alimentaram-se de 88%, 85% e 83,8% dos uredosporos, respectivamente. Para ninfas do 3º ínstar, a porcentagem de consumo de uredosporos (75,6%) foi estatisticamente significativo em comparação com os outros grupos. No experimento em casa de vegetação, aos 28 dias após a inoculação das plantas com 9,9 x 104 uredosporos, a porcentagem de consumo de uredosporos foi de 81,7%. Nossos resultados confirmaram a fungivoria de D. luteipes em uredosporos de P. polysora. Este é o primeiro relato de fungivoria de D. luteipes, que pode ter papel importante no controle biológico de P. polysora em milho.

2.
Braz J Biol ; 83: e243890, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133491

RESUMO

Doru luteipes (Scudder, 1876) is an omnivorous predator that finds different food resources in the corn plant: eggs of Spodoptera frugiperda (J.E. Smith, 1797), uredospores of Puccinia polysora (Underw, 1897), and pollen. Knowing the survival and food preferences of this predator is essential to define its relevance as a biological control agent. We hypothesize that the foraging behavior and predatory capacity of D. luteipes may be affected when several food resources, especially eggs of S. frugiperda, uredospores of P. polysora, and pollen are concurrently in the same plant. The survival of D. luteipes in the nymph stage and their preference among food resources, often available in corn plants, were determined. To verify the survival of D. luteipes, newly hatched nymphs were fed exclusively with 1- uredospores of P. polysora, 2- eggs of S. frugiperda, 3- corn pollen, 4- a combination of uredospores + eggs, and 5- artificial diet (control). In another experiment, nymphs and adults of D. luteipes with 24 and 48 hours of fasting were individually released in the center of a container with four diets: 1- uredospores of P. polysora, 2- eggs of S. frugiperda, 3- corn pollen, 4- artificial diet, and maintained for 10 minutes, to evaluate the food choice and feeding time. The exclusive feeding with S. frugiperda eggs caused low nymph survival (8%), but the combination of P. polysora uredospores + S. frugiperda eggs allowed 58.3% survival. D. luteipes preferred feeding during the nighttime and the most significant proportions of choices by nymphs and adults were for pollen and diet, with adults spending more time eating pollen. These findings indicate that the trophic choices of D. luteipes are relevant to understand its contribution as an agent to control pest insects and fungal diseases in corn.


Assuntos
Insetos , Comportamento Predatório , Animais , Larva , Ninfa , Spodoptera , Zea mays
3.
Braz J Biol ; 82: e238763, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33825760

RESUMO

We report the discovery that the earwig predator Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) feed on Puccinia polysora Underw uredospore, the causal agent of Southern Rust of Corn (SRC), which is a primary disease affecting the maize crop in Brazil. We performed experiments in laboratory and greenhouse to test the effect of D. luteipes (1st/2nd and 3rd/4th instars, and adults) fungivory on the P. polysora uredospore concentration. All trials showed a significant reduction of the initial concentration of uredospore. There was a reduction in uredospore concentration with increase in number of D. luteipes feeding on them. We also tested the uredospore consumption by quantifying its percentage in the feces of D. luteipes. Nymphs of the 2nd, 4th instar and adults fed 88%, 85%, and 83.8% of the uredospore, respectively. For nymphs of the 3rd instar, the percentage of uredospore consumption (75.6%) was statistically significant compared with the other groups. In greenhouse experiment, at twenty-eight days after plant inoculation with 9.9 x 104 uredospores, the percentage of uredospore consumption was 81.7%. Our results confirmed the fungivory of D. luteipes on P. polysora uredospore. This is the first report of D. luteipes fungivory, which may play an important role in the biological control of P. polysora in corn.


Assuntos
Zea mays , Animais , Brasil , Ninfa
4.
Braz. j. biol ; 81(1): 154-163, Feb. 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153314

RESUMO

Abstract Understanding the ecological and toxicological relationship between genetically modified cultivars (GM) and biological control agents is of great importance for discussions related to the compatability of GM cultivars and integrated management strategies for pest resistance. The present study evaluated the search behavior and predatory capacity of Orius insidiosus (Say) (Hemiptera: Anthocoridae) and Doru luteipes (Scudder) (Dermaptera: Forficulidae) on eggs and caterpillars of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) resistant or not to the protein Cry1F expressed in Bt corn. To determine the search time, a stopwatch was run until the capture of the first prey, predation capacity was evaluated by counting the prey remaining after 24 hours of infestation. The injuries of S. frugiperda in genetically modified and conventional corn in the presence and absence of predators was also evaluated. The predators were not able to distinguish between resistant and susceptible prey (eggs or caterpillars), given the predatory behaviour observed. There was no difference in searching time or predatory capacity between the predators for eggs and caterpillars of either resistant or susceptible S. frugiperda. In the presence of predators, the injury scores for resistant S. frugiperda on the Bt corn plants were lower. It was concluded that O. insidiosus and D. luteipes did not notice the presence of the protein Cry1F in the prey S. frugiperda, which may facilitate the combined use of GM corn and biological control in integrated management programs and for management of pest resistance.


Resumo O entendimento de relações ecológicas e toxicológicas envolvendo culturas geneticamente modificadas (GM) e agentes de controle biológico é de grande importância para discussões relativas à compatibilidade de culturas GM com estratégias de manejo integrado e manejo de resistência de pragas. Este trabalho avaliou o comportamento de busca e a capacidade predatória de Orius insidiosus (Say) (Hemiptera: Anthocoridae) e Doru luteipes (Scudder) (Dermaptera: Forficulidae) sobre ovos e lagartas de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) resistente ou não à proteína Cry1F expressa em milho Bt. Para determinar o tempo de busca foi utilizado um cronômetro que foi disparado até a captura da primeira presa; a capacidade de predação foi avaliada através da contagem das presas remanescentes 24 h após infestação. Também foram avaliadas as injúrias de S. frugiperda em milho transgênico e milho convencional na presença ou ausência dos predadores. Os predadores não foram capazes de distinguir entre presas (ovos ou lagartas) resistentes e suscetíveis, considerando os comportamentos predatórios avaliados. Não houve diferença no tempo de busca e capacidade predatória sobre ovos e lagartas de S. frugiperda resistente ou suscetível entre os predadores. Na presença dos predadores, as notas de injúria de S. frugiperda resistente nas plantas de milho Bt foram menores. Conclui-se que O. insidiosus e D. luteipes não percebem a presença da proteína Cry1F na presa S. frugiperda, o que pode contribuir para o uso integrado de milho GM e controle biológico em programas de manejo integrado e manejo de resistência de pragas.

5.
Psychol Health Med ; : 1-11, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32266824

RESUMO

BACKGROUND: nociceptive pain from joint damage caused by autoimmune inflammatory disease is expected in rheumatoid arthritis. However, neuropathic pain also occurs and persists even with the disease under control. This study aimed to investigate factors associated with neuropathic pain in rheumatoid arthritis by considering sociodemographic and behavioral data as well as lifestyle and clinical aspects in a self-referenced afro-descendant ethnicity sample. METHODS: In a cross-sectional study, the Douleur Neuropathique 4, Health Assessment Questionnaire, the Hospital Anxiety and Depression Scale and sociodemographic characteristics were used. Additionally, a Bivariate analysis was performed, followed by hierarchical multiple logistic regression, with results expressed as odds ratio and 95% confidence intervals. RESULTS: the frequency of NP was at a proximal level consisting of clinical characteristics related to anxiety (p=0.03) and depression (p=0.04). When a hierarchical multiple logistic regression analysis was conducted, an independent association was identified between neuropathic pain and black race. At the third and fourth stages, when the clinical variables were adjusted by race, an association was found with moderate functionality (p=0.04) and anxiety (p=0.04). CONCLUSION: neuropathic pain in rheumatoid arthritis is related to the Afro-descendant ethnicity that affects functionality and anxiety levels.

6.
Braz J Biol ; 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32159617

RESUMO

Understanding the ecological and toxicological relationship between genetically modified cultivars (GM) and biological control agents is of great importance for discussions related to the compatability of GM cultivars and integrated management strategies for pest resistance. The present study evaluated the search behavior and predatory capacity of Orius insidiosus (Say) (Hemiptera: Anthocoridae) and Doru luteipes (Scudder) (Dermaptera: Forficulidae) on eggs and caterpillars of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) resistant or not to the protein Cry1F expressed in Bt corn. To determine the search time, a stopwatch was run until the capture of the first prey, predation capacity was evaluated by counting the prey remaining after 24 hours of infestation. The injuries of S. frugiperda in genetically modified and conventional corn in the presence and absence of predators was also evaluated. The predators were not able to distinguish between resistant and susceptible prey (eggs or caterpillars), given the predatory behaviour observed. There was no difference in searching time or predatory capacity between the predators for eggs and caterpillars of either resistant or susceptible S. frugiperda. In the presence of predators, the injury scores for resistant S. frugiperda on the Bt corn plants were lower. It was concluded that O. insidiosus and D. luteipes did not notice the presence of the protein Cry1F in the prey S. frugiperda, which may facilitate the combined use of GM corn and biological control in integrated management programs and for management of pest resistance.

7.
Braz. j. biol ; 79(4): 584-588, Nov. 2019. tab
Artigo em Inglês | LILACS | ID: biblio-1001478

RESUMO

Abstract The properties of maize pollen in the diet of Doru luteipes were determined by biological responses of the predator feeding on natural preys and artificial diet. The biological parameters of D. luteipes fed on Spodoptera frugiperda (Smith, 1797) eggs, maize pollen, Rhopalosiphum maidis (Fitch, 1856) + maize pollen and R. maidis were assessed. The effect of pollen on artificial diet on the biological variables of the predator nymphs and adults were also evaluated. Time span of nymphal development was greater for D. luteipes exclusively fed on earwigs, with the lowest rate of nymph survival. However, maize pollen plus earwigs in the diet provided the predator´s highest survival rate, whilst percentage of fertile females was double when fed on diets composed of S. frugiperda and R. maidis eggs. Development period decreased when D. luteipes nymphs consumed artificial diet plus pollen but there were high fecundity rates (number of laying/female and total egg/female) and a greater percentage of fertile females when they were fed on maize pollen.


Resumo Os benefícios do pólen de milho na composição da dieta de Doru luteipes foram determinados por meio das respostas biológicas desse predador alimentado com presas naturais e dieta artificial. Inicialmente, avaliaram-se parâmetros biológicos de D. luteipes alimentados com: ovos de Spodoptera frugiperda (Smith, 1797), pólen de milho, pólen de milho e Rhopalosiphum maidis (Fitch, 1856) e R. maidis. Posteriormente, verificou-se o efeito da presença do pólen em dieta artificial nas variáveis ​​biológicas de ninfas e adultos do predador. O período de desenvolvimento ninfal foi maior para D. luteipes alimentado, exclusivamente, com pulgões, sendo esta dieta a que propiciou menor sobrevivência ninfal. No entanto, a adição de pólen de milho na dieta com pulgões proporcionou maior taxa de sobrevivência do predador e, o percentual de fêmeas que ovipositaram foi praticamente o dobro em relação às dietas compostas por ovos de S. frugiperda e R. maidis. Quando ninfas de D. luteipes consumiram a dieta artificial adicionada com pólen verificou-se redução no período de desenvolvimento ninfal e quando o pólen de milho foi fornecido apenas na fase adulta houve uma maior fecundidade (número de posturas/fêmea e total de ovos/fêmea) e porcentagem de fêmeas que ovipositaram.


Assuntos
Animais , Feminino , Pólen , Zea mays , Cadeia Alimentar , Insetos/fisiologia , Brasil , Dieta , Insetos/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia
8.
Braz J Biol ; 79(4): 584-588, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30365637

RESUMO

The properties of maize pollen in the diet of Doru luteipes were determined by biological responses of the predator feeding on natural preys and artificial diet. The biological parameters of D. luteipes fed on Spodoptera frugiperda (Smith, 1797) eggs, maize pollen, Rhopalosiphum maidis (Fitch, 1856) + maize pollen and R. maidis were assessed. The effect of pollen on artificial diet on the biological variables of the predator nymphs and adults were also evaluated. Time span of nymphal development was greater for D. luteipes exclusively fed on earwigs, with the lowest rate of nymph survival. However, maize pollen plus earwigs in the diet provided the predator´s highest survival rate, whilst percentage of fertile females was double when fed on diets composed of S. frugiperda and R. maidis eggs. Development period decreased when D. luteipes nymphs consumed artificial diet plus pollen but there were high fecundity rates (number of laying/female and total egg/female) and a greater percentage of fertile females when they were fed on maize pollen.


Assuntos
Cadeia Alimentar , Insetos/fisiologia , Pólen , Zea mays , Animais , Brasil , Dieta , Feminino , Insetos/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia
10.
Braz. j. biol ; 78(1): 13-17, Feb. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-888832

RESUMO

Abstract Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays), despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested by T. urticae (clean plants clean) and, 30 infested by the spider mite. Infestation of maize plants by T. urticae reduced the conspecific female adult survival. However, no change in the survival of immature or reproduction was observed. These results suggest the induction of induced direct resistances in maize by T. urticae. This is first report of direct resistance induction in Z. mays by the two-spotted spider mite T. urticae.


Resumo As plantas podem ser atacadas por uma grande diversidade de herbívoros. Sendo assim, o desenvolvimento de mecanismos de proteção para se defenderem destes agentes é um diferencial para a sobrevivência e reprodução. Ao longo da evolução, diversos mecanismos de resistência contra herbívoria foram desenvolvidos pelas plantas. Mecanismos de resistência induzida direta e indireta podem manifestar-se em plantas após o ataque de herbívoros. O ácaro-rajado Tetranychus urticae não é uma praga na cultura da cultura do milho (Zea mays), apesar de ser relatado infestando plantas, as quais podem apresentar resistências contra tal herbívoro. Testamos a hipótese de que plantas de milho seriam capazes de induzir resistências diretas à T. urticae após o ataque, avaliando o efeito da infestação de T. urticae de plantas em milho sobre seu desenvolvimento e reprodução de coespecíficos. Testamos resistência induzida direta realizando uma infestação e medindo os parâmetros biológicos em uma segunda infestação. Plantas de milho foram divididas em dois grupos: 30 plantas não por T. urticae (plantas limpas) e 30 plantas infestadas pelo ácaro-rajado. A infestação de plantas de milho por T. urticae reduziu a sobrevivência de fêmeas adultas do coespecífico. Entretanto, não foi observada alteração na sobrevivência das formas imaturas ou reprodução. Tais resultados sugerem a indução de resistências induzida diretas em milho por T. urticae. Este é primeiro relato de indução de resistência direta em Z. mays pelo ácaro-rajado T. urticae.


Assuntos
Animais , Produtos Agrícolas/fisiologia , Produtos Agrícolas/parasitologia , Zea mays/parasitologia , Tetranychidae/patogenicidade , Resistência à Doença , Infestações por Ácaros , Zea mays/fisiologia
12.
Braz J Biol ; 78(1): 13-17, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28658392

RESUMO

Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays), despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested by T. urticae (clean plants clean) and, 30 infested by the spider mite. Infestation of maize plants by T. urticae reduced the conspecific female adult survival. However, no change in the survival of immature or reproduction was observed. These results suggest the induction of induced direct resistances in maize by T. urticae. This is first report of direct resistance induction in Z. mays by the two-spotted spider mite T. urticae.


Assuntos
Produtos Agrícolas , Resistência à Doença , Infestações por Ácaros , Tetranychidae , Zea mays , Animais , Produtos Agrícolas/parasitologia , Produtos Agrícolas/fisiologia , Tetranychidae/patogenicidade , Zea mays/parasitologia , Zea mays/fisiologia
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