Biological Control Unit Embrapa Algodao

João Pessoa, Brazil

Biological Control Unit Embrapa Algodao

João Pessoa, Brazil
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Fernandes F.S.,Biological Control Unit Embrapa Algodao | Ramalho F.S.,Biological Control Unit Embrapa Algodao | Nascimento J.L.,Biological Control Unit Embrapa Algodao | Malaquias J.B.,Biological Control Unit Embrapa Algodao | And 2 more authors.
Bulletin of Entomological Research | Year: 2012

Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect. © Copyright Cambridge University Press 2011.


Malaquias J.B.,Biological Control Unit Embrapa Algodao | Ramalho F.S.,Biological Control Unit Embrapa Algodao | Fernandes F.S.,Biological Control Unit Embrapa Algodao | Junior J.L.N.,Biological Control Unit Embrapa Algodao | And 2 more authors.
Annals of the Entomological Society of America | Year: 2010

Effects of photoperiod on reproduction and longevity of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) were assessed under seven different photophases (10, 11, 12, 13, 14, 15, and 16 h) at a constant 28 ± 1°C temperature and 70 ± 10% RH in the laboratory. Photoperiod affected the longevity of P. nigrispinus females. The highest longevity (24.10 d) occurred with a 15-h photoperiod, compared with longevity of 9.75 d at 12-h photoperiod. The preoviposition period of P. nigrispinus was influenced by the photoperiod. The preoviposition period of P. nigrispinus was longer for the 16-h photoperiod (7.25d) than for the 12- (4.06d), 13- (4.00 d), and 14-h (3.68d) photoperiod. The postoviposition period, the number of egg clutches per female per day, and the interval between egg clutches were not affected by the photoperiod. The postoviposition period ranged from 1.46 d (at 14 h of light) to 3.71 d (at 11 h of light). The number of egg clutches per female per day varied between 0.19 (at 11 h or 14 h of light) and 0.40 (at 15 h of light). The interval between egg clutches ranged from 1.29 d (at 14 h of light) to 2.07 d (at 11 h of light). The variation in the number of eggs and egg clutches per female of P. nigrispinus in relation to their age varied according to the photophase to which they were exposed. The fecundity of P. nigrispinus females was higher in 15 h of light. These informations serve as a valuable ecological variable in modeling population dynamics of P. nigripinus, both in the field and in the laboratory, thereby contributing to the success of A. argillacea control programs. © 2010 Entomological Society of America.


Malaquias J.B.,Biological Control Unit Embrapa Algodao | Ramalho F.S.,Biological Control Unit Embrapa Algodao | Omoto C.,University of Sao Paulo | Godoy W.A.C.,University of Sao Paulo | Silveira R.F.,University of Sao Paulo
Ecotoxicology | Year: 2014

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is one of the most common asopine species in the neotropical region and its occurrence was reported in several countries of South and Central America, as an important biological control agent for many crops. This study was carried out to identify the imidacloprid impacts on the functional response of predator P. nigrispinus fed on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) strain resistant to lambda-cyhalothrin, on Bt cotton expressing Cry1Ac (Bollgard®). Spodoptera frugiperda larvae were used in the following conditions: resistant (1) and susceptible (2) strains to lambda-cyhalothrin fed on Bollgard® cotton leaves (DP 404 BG); and resistant (3) and susceptible (4) strains to lambda-cyhalothrin fed on non-genetically modified cotton leaves (cultivar DP4049). The predatory behavior of P. nigrispinus was affected by imidacloprid and the type II asymptotic curve was the one that best described the functional response data. Handling time (T h ) of predator females did not differ among treatments in the presence of imidacloprid. The attack rate did decrease, however, due to an increase in the density of larvae offered. Regardless of the treatment (S. frugiperda strain or cotton cultivar), the predation of P. nigrispinus females on S. frugiperda larvae was significantly lower when exposed to imidacloprid, especially at a density of 16 larvae/predator. The predation behavior of P. nigrispinus on S. frugiperda larvae is affected by the insecticide imidacloprid showing that its applications should be used in cotton crop with caution. © 2013 Springer Science+Business Media New York.


Nascimento A.R.B.,Biological Control Unit Embrapa AlgodAo | Ramalho F.S.,Biological Control Unit Embrapa AlgodAo | Azeredo T.L.,Biological Control Unit Embrapa AlgodAo | Fernandes F.S.,Biological Control Unit Embrapa AlgodAo | And 3 more authors.
Annals of the Entomological Society of America | Year: 2011

Quantitative analysis of the consumption and use by herbivore pest's of the host plant is a common tool used for studying the interaction between insects and plants. Our goals were to quantify cotton leafworm, Alabama argillacea (HÃ1/4bner) (Lepidoptera: Noctuidae), larval consumption rate in three cotton, Gossypium hirsutum L., cultivars that produce colored cotton fibers, and the effects of the consumption rate on A. argillacea pupal weight in greenhouse conditions. Larvae consumed a maximum of 0.69-1.03 g of leaf tissue over a 24-h period in all cultivars tested. Total consumption by A. argillacea larvae was highest when fed with 'â€̃BRS 200'-leaves (2.89 g) and the lowest when fed with leaves from 'â€̃BRS Safira'-(2.26 g). The regression analysis showed significant relationships between the quantity of leaf tissue consumed and pupal weights for each cotton cultivar. A. argillacea larvae fed on BRS 200 demonstrated a longer developmental period (14.84 d) than larvae fed on 'â€̃BRS Rubi'-leaves (11.62 d) or BRS Safira (11.14 d). We concluded that BRS Safira presents the best quality food source for A. argillacea, BRS 200 is the worst, and BRS Rubá is intermediate. The longer developmental times of A. argillacea on BRS 200 may allow longer windows of opportunity for the use of biological control agents to reduce the damage caused by this pest and also would complete less generations per phenological cycle of the cotton crop. © 2011 Entomological Society of America.


Silva C.A.D.,Biological Control Unit Embrapa Algodao | Ramalho F.S.,Biological Control Unit Embrapa Algodao
Journal of Pest Science | Year: 2013

The high cost of insecticides, the emergence of insecticide resistance in populations of a number of insect species and other problems arising from their continuous use, such as biological imbalance, cotton fiber waste, and environmental pollution, have prompted the development of new technologies aiming the control of Anthonomus grandis Boheman in cotton crops. This study evaluated the level of protection conferred by kaolin clay foliar spraying to cotton plants against boll weevil damage. Treatment-tested spraying kaolin or endosulfan on cotton plants. The highest percentage of oviposition-punctured squares were observed in the control, and the lowest percentages in the treatments sprayed with endosulfan and kaolin in a systematic manner and where the boll weevil reached the economic threshold at all assessments. The greatest numbers of non-attacked bolls by weevils and cotton-seed yield were observed under the endosulfan treatments, followed by the treatments of kaolin spraying. The smallest number of bolls and lowest cotton-seed yield were observed for the control plots. These finding are of practical significance because they may reduce the cotton production cost and environmental impacts of chemical pesticides and make possible the production of organic cotton with the presence of boll weevils. © 2013 Springer-Verlag Berlin Heidelberg.


PubMed | Biological Control Unit Embrapa Algodao
Type: Comparative Study | Journal: Bulletin of entomological research | Year: 2011

Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect.


PubMed | Biological Control Unit Embrapa Algodao
Type: Evaluation Studies | Journal: Journal of economic entomology | Year: 2012

The fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a major pest of fennel, Foeniculum vulgare Miller in northeast region of Brazil. We hypothesize that intercropping can be used as an alternative pest management strategy to reduce aphid yield loss in fennel. Thus, we investigated the severity of fennel plant damage in relation to infestation by the fennel aphid and predation by Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) (spotless lady beetle), green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and Scymnus spp. (Coleoptera: Coccinellidae) in sole fennel plots and plots of fennel intercropped with cotton with colored fibers. The fennel aphid populations in nontreated plots were significantly larger in sole fennel plots than in intercropped plots. The highest densities of C. sanguinea, green lacewings and Scymnus spp., associated with the suppression of fennel aphid populations was found in fennel in the intercropping systems. Fennel aphids reduced the fennel seed yield by 80% in the sole fennel plots compared with approximately 30% for all intercropping systems. The results obtained in this research are of practical significance for designing appropriate strategies for fennel aphid control in fennel-cotton intercropping systems. In summary, intercropping fennel with cotton with colored fibers apparently promoted biocontrol of fennel aphid in fennel.


PubMed | Biological Control Unit Embrapa Algodao
Type: Journal Article | Journal: Ecotoxicology (London, England) | Year: 2014

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is one of the most common asopine species in the neotropical region and its occurrence was reported in several countries of South and Central America, as an important biological control agent for many crops. This study was carried out to identify the imidacloprid impacts on the functional response of predator P. nigrispinus fed on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) strain resistant to lambda-cyhalothrin, on Bt cotton expressing Cry1Ac (Bollgard()). Spodoptera frugiperda larvae were used in the following conditions: resistant (1) and susceptible (2) strains to lambda-cyhalothrin fed on Bollgard() cotton leaves (DP 404 BG); and resistant (3) and susceptible (4) strains to lambda-cyhalothrin fed on non-genetically modified cotton leaves (cultivar DP4049). The predatory behavior of P. nigrispinus was affected by imidacloprid and the type II asymptotic curve was the one that best described the functional response data. Handling time (T h ) of predator females did not differ among treatments in the presence of imidacloprid. The attack rate did decrease, however, due to an increase in the density of larvae offered. Regardless of the treatment (S. frugiperda strain or cotton cultivar), the predation of P. nigrispinus females on S. frugiperda larvae was significantly lower when exposed to imidacloprid, especially at a density of 16 larvae/predator. The predation behavior of P. nigrispinus on S. frugiperda larvae is affected by the insecticide imidacloprid showing that its applications should be used in cotton crop with caution.

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