Navegando por Assunto "Controle biológico"

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Acesso aberto (Open Access)
Artropodofauna associada a diferentes sistemas de cultivo de açaizeiro no nordeste paraense
(Universidade Federal do Pará, 2012-08-31) RIBEIRO, Suelem Moreira; LEMOS, Walkymário de Paulo; http://lattes.cnpq.br/6841621785311887
The açaí palm (Euterpe oleracea Mart.) is an important crop for Pará agribusiness for reaching new consumer markets in Brazil and in different countries. However, the growing commercial expansion that açaí has shown in recent years has reflected also in the significant increase in its acreage, which may result in the incidence of insect pests associated with these agroecosystems, thus requiring research actions focused on the alternative management and control of these biotic constraints. Simultaneously, new models of fruit crops have been tested successfully in the state of Pará, highlighting, among them, Agroforestry Systems (AFSs), aimed at increasing the number of crops (annual, permanent and / or forestry) implanted in an area. Among the benefits of AFSs stands out for its potential to maintain and multiply diversified beneficial entomofauna when compared to monocultures. Therefore, this study aimed to understand and compare the biodiversity of arthropods associated with the açaí palm in different cropping systems of the family farm in the northeast of Pará. It was analyzed three areas, two AFSs areas that had açaí palm as one of the main crops in the Marapanim town and an area of açaí monoculture, in the Igarapé-Açu town. In each area were implanted 45 Pitfall traps, which were equally distributed in three subareas: (a) near the açaí palm plants inside the plantation; (b) in the secondary forest around the crops; and (c) in the transition area between cultivation and secondary forest. Samples were collected into four distinct periods, one in the rainy season (CH), a transition period between the rainy and dry (CH / SE), one in the dry season (SE) and another collection corresponding to the transition period between dry and rainy (SE / CH). The insects biodiversity assessments were made in the soil (Pitfall traps). Arthropods (insect pests and natural enemies and spiders) collected in the field were stored in plastic containers (150 mL) containing 70% alcohol, and transported to the Entomology Laboratory of Embrapa Amazônia Oriental, where they were sorted, quantified and identified taxonomically . It was concluded that the periods of the year that most favor the presence of soil arthropods, regardless of crop fields, are the transition periods CH / SE and SE / CH. There was also a reduction in the population of ants in the three areas of secondary forest analyzed, and the gender Solenopsis (Westwood), Wasmannia (Forel) and Azteca (Forel) the most frequent in these areas. The area with açaí monoculture has a higher abundance of ants than the two AFSs analyzed. The spider family Lycosidae was found most frequently in this study, with the most abundant being Pacovosa gender. Agroforestry systems, if properly managed, form conducive environment for the arthropods species diversity like spiders and ants, which are admittedly efficient organisms in natural control of insect pests in crops. Transition periods grouped more individuals, followed by AFS area located in the Marapanim town, which represents the area most changed among the analyzed areas. Secondary forests are areas with smaller grouping of individuals and smaller gender diversity of ants and spiders.
Acesso aberto (Open Access)
Diversidade de inimigos naturais em cultivos de palma de óleo Elaeis guineensis implantados em sistemas agroflorestais para agricultura familiar
(Universidade Federal do Pará, 2010-08-30) ESPIRITO SANTO, Lorena Nunes do; LEMOS, Walkymário de Paulo; http://lattes.cnpq.br/6841621785311887
The cultivation of palm oil or palm oil (Elaeis guineensis Jacq.) is a promising alternative for the recovery of degraded areas in the Brazilian Amazon, and promote the establishment of man in the field. However, when established in monoculture systems presents favorable conditions for the emergence and proliferation of insect pests, especially borers and defoliators. Thus, this research aimed to identify and quantify the diversity of insect pests and their natural enemies in three different systems of cultivation of oil palm in the city of Tome-Acu, Para, between May 2009 and January 2010. Two properties of oil palm cultivated as main crop in agroforestry (SAF) with different combinations of land preparation. The third study area was a monoculture oil palm, characterizing the current model of palms growing in the Amazon region. In all areas studied palm oil showed similar age and were monitored during May, June, October, December 2009 and January 2010. Was evaluated in the different systems, the diversity of insect pests and natural enemies in two separate statements: soil and plant canopy. Traps "pitfall" were used for the collection of soil arthropods (particularly predators), while yellow sticky traps were used to capture insects present in the shoots. The rainfall was recorded during the research in all areas studied. The orders with the highest species diversity in biodiverse, and monoculture systems, regardless of the type of trap, were Hymenoptera, Hemiptera, Araneae and Coleoptera, which are possibly associated with maintaining the balance of herbivore populations in these environments. The similarity of species collected in pitfall traps and adhesive between the areas studied was influenced by the history of the occupation of the areas and months of collection, and the precipitation effect on the diversity of arthropods collected in the different systems of cultivation of palm oil. Different kinds of ants (eg., Solenopsis and Pheidole) representatives gathered in this research are predators, a fact which reinforces the hypothesis of the same potential to act as natural enemies of pests in these systems. The different systems of cultivation of oil palm evaluated reported great diversity of spiders, possibly by offering diversified food resource availability (eg., Insects) for these generalist natural enemies. This research is the first to record the diversity of soil spiders in oil palm cultivation in the Eastern Brazilian Amazon, a fact that provides insights for future studies on the ecological group. Although this study presents results of the first two years of implementation of the cultivation of oil palm in the field, they reveal the importance of studies that aim to assess the influence of biodiverse environments in the maintenance and multiplication of natural enemies to act in the biological control of insect pest of many crops, particularly palms.
Acesso aberto (Open Access)
Prospecção de biocida em plantas amazônicas e exóticas, visando seu uso racional
(Universidade Federal do Pará, 2009-02-19) DANTAS, Eneida Pontes Mota; SOUZA FILHO, Antonio Pedro da Silva; http://lattes.cnpq.br/1691897760012496
The main method of controlling the cattle tick Boophilus microplus is the use of chemical acaricides during the parasite phase. However, the intense use of this method is causing economic damage and promoting the rapid selection of resistant ticks. Besides the risk of residues in milk, in meat and environmental contamination. Within this context, the use of herbal points out as an alternative to control the tick and can reduce the economic and environmental impacts of the use of synthetic chemicals. On this way, the purpose of this study was to evaluate "in vitro" the effect of essential oils of grass-salsa (Cymbopogon winteranius Jowitt) and priprioca (Cyperus articulatus L.), chemicals isolated substances from timbó (Derris nicou; Derris urucu): rotenone, rotenolone and degueline and Andiroba’s oil (Carapa guianensis Aublet.) and neem (Azadirachta indica A. Juss.) in the control of ticks. The searches were conducted on the premises of the Animal Research Unit "Sen. Álvaro Adolpho, of "the Brazilian Enterprise for Agricultural Research - Embrapa Eastern Amazon, in the city of Belém, state of Pará, in the period from March to July of 2008. The engorged females of Boophilus microplus were collected manually, from naturally infected cattle on private property located within an hour of Belém. After collection, they were transported to the laboratory in plastic containers, marked, cleaned and aerated. In the laboratory, they were rinsed in running water, dried on absorbent paper and weighed on analytical balance (accuracy of 0.0001 g). The methodology used was the immersion of teleogines by time of five minutes. After soaking, the ticks were dried on absorbent paper, set in petri dishes and kept at room temperature for completion of the posture. Throughout the trial period the temperature and relative humidity was measured in the laboratory using a termohigrometer. The experimental design used was completely randomized. The percentage of mortality of engorged females of B. microplus, on 5 and 15, varied: 45% to 90%, 37% to 90% and 60 to 90%, 60% to 90% for grass-salsa and priprioca respectively. The results for the stance showed no statistical difference between the concentrations 2% and 10% on the control (water + ethanol). However, there was a difference in the concentration 50% for both grass-salsa as priprioca. For grass-salsa, this concentration was observed egg laying infertile. Regarding the percentage of efficiency of the product, the values obtained were: 100%; 95.63%, 98.77%, 100% and 99,30%, 96,97%, 99,85% and 100% to the effects of essential oil of salsa and grass-priprioca concentrations 2%, 5%, 10%, 50%, respectively. Mortality rates, on the 5th , ranged from 37% to 41%, 49% to 64% and 52% to 41% for rotenone, rotenolone and degueline from low to high concentration, respectively. All substances tested showed significantly higher mortality rate than those obtained by the control group (water + ethanol). The best results were posture of percentage of 49% and 26% for the rotenone degueline and 200ppm, respectively and 34% for rotenolone at 100ppm. The percentage of efficiency in tests with rotenone were 95.24% and 98.68% for rotenolone the order of 97.29%, 98.08%, 100% and degueline 95.45%, 98.23% and 100 %, from 100ppm, 200ppm and 300ppm, respectively. To andiroba and neem, the percentage of mortality was observed on 15 and has a natural behavior of the life cycle of ticks because there was no statistical difference between the control (water + ethanol) and treatments in different concentrations. To andiroba and neem the higher efficiency obtained was 98,01% and 100%, at concentration 50%, respectively.
Acesso aberto (Open Access)
Sperm depletion: a cost for single mated females of Podisus nigrispinus (Dallas, 1851) (Heteroptera: Pentatomidae)
(2006-11) SOUTO, Leandro Sousa; EVANGELISTA JÚNIOR, Walter Santos; LIMA, Eraldo Rodrigues; ZANUNCIO, José Cola; FONSECA, Marcy das Graças
The aim of this work was to test if egg viability of polyandrous females was increased with increasing number of matings. Longevity and reproductive output of females of the predatory stinkbug Podisus nigrispinus that were allowed to mate for 0, 1, 2, 3 times or were in the continuous presence of the same male was evaluated. Polyandry resulted in diminished sperm depletion. Females that had mated three times or that were in continuous presence of a male produced more offspring than females that mated once or twice throughout their lifetime. There was a negative correlation of mating history on female longevity. Results indicated that remating, either with same male or with different males were crucial for maximization of the reproductive success of females.
Acesso aberto (Open Access)
Trichospilus diatraeae (Hymenoptera: Eulophidae): development and reproduction in Lepidoptera palm oil pests
(Instituto Internacional de Ecologia, 2019-09) RIBEIRO, Rafael Coelho; ZANUNCIO, José Cola; PARREIRA, Mariana Casari; MAHMOUD, Hany Ahmed Fouad Hanafy; PIKART, Tiago Georg; SOARES, Marcos Alvarega; CASTRO, Eustaquio Vinicius Ribeiro
Brazil is a leading palm oil producer, but the defoliating caterpillars Opsiphanes invirae Hübner Brassolis sophorae L. (Lepidoptera: Nymphalidae) can reduce the productivity of this crop. The aim of this study was to evaluate the development and reproduction of the parasitoid Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) in pupae of these oil palm defoliators. Ten O. invirae or B. sophorae pupae with up to two days old were exposed each to 30 T. diatraeae females for 48 hours. Parasitism and emergence of the progeny of T. diatraeae were similar in pupae of both Lepidoptera defoliators. The life cycle of this parasitoid was shorter in O. invirae (21.50 ± 0.42 days) pupae than with those of B. sophorae (27.60 ± 1.80 days). The number of the progeny (669.00 ± 89.62) and dead immature (217.13 ± 58.18) of T. diatraeaewere higher in B. sophorae pupae than in those of O. invirae with 447.83 ± 51.52 and 13.50 ± 5.23, respectively. The sex ratio and female and male longevity of T. diatraeae emerged from these hosts were similar. The reproductive traits, especially the number of individuals (offspring) of T. diatraeae were better with B. sophorae pupae than with those of O. invirae.