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Alois A Bell - One of the best experts on this subject based on the ideXlab platform.

  • relationship between piercing sucking insect control and internal lint and seed rot in southeastern cotton gossypium hirsutum l
    Journal of Economic Entomology, 2015
    Co-Authors: Enrique G Medrano, Jeremy K Greene, Jesus F Esquivel, Alois A Bell, Phillip M Roberts, J S Bacheler, James J Marois, David L Wright, Robert L Nichols, Sara E Duke
    Abstract:

    In 1999, crop consultants scouting for stink bugs (Hemiptera spp.) in South Carolina discovered a formerly unobserved seed rot of cotton that caused yield losses ranging from 10 to 15% in certain fields. The disease has subsequently been reported in fields throughout the southeastern Cotton Belt. Externally, diseased Bolls appeared undamaged; internally, green fruit contain pink to dark brown, damp, deformed lint, and necrotic seeds. In greenhouse experiments, we demonstrated transmission of the opportunistic bacterium Pantoea agglomerans by the southern green stink bug, Nezara viridula (L.). Here, green Bolls were sampled from stink bug management plots (insecticide protected or nontreated) from four South Atlantic coast states (North Carolina, South Carolina, Georgia, and Florida) to determine disease incidence in the field and its association with piercing-sucking insects feeding. A logistic regression analysis of the boll damage data revealed that disease was 24 times more likely to occur (P = 0.004) in Bolls collected from plots in Florida, where evidence of pest pressure was highest, than in Bolls harvested in NC with the lowest detected insect pressure. Fruit from plots treated with insecticide, a treatment which reduced transmission agent numbers, were 4 times less likely to be diseased than Bolls from unprotected sites (P = 0.002). Overall, punctured Bolls were 125 times more likely to also have disease symptoms than nonpunctured Bolls, irrespective of whether or not plots were protected with insecticides (P = 0.0001). Much of the damage to cotton Bolls that is commonly attributed to stink bug feeding is likely the resulting effect of vectored pathogens.

  • potential for nezara viridula hemiptera pentatomidae to transmit bacterial and fungal pathogens into cotton Bolls
    Current Microbiology, 2009
    Co-Authors: Enrique G Medrano, Jeremy K Greene, Jesus F Esquivel, Alois A Bell, Phillip M Roberts, J S Bacheler, James J Marois, David L Wright, Robert L Nichols, Juan D Lopez
    Abstract:

    Recently, we showed that the southern green stink bug (SGSB), Nezara viridula (L.), can transmit Pantoea agglomerans (Ewing and Fife), an opportunistic bacterium, into green cotton Bolls resulting in plant disease. Here, we hypothesized that our established model could be used to determine if the SGSB was a general, non-discriminate vector by using two other opportunistic bacterial pathogens of Bolls (Pantoea ananatis [Serano] and Klebsiella pneumoniae [Schroeter]) and the known fungal pathogen Nematospora coryli (Peglion). Variants of P. ananatis (strain Pa-1R) and K. pneumoniae (strain Kp 5-1R) selected for rifampicin (Rif) resistance were used as bacterial opportunists. N. coryli was detected only from laboratory-reared SGSB directly exposed to the fungus. Both Pa-1R and Kp 5-1R were recovered from SGSB previously provided a contaminated food source (2 days), sterile food (5 days), and then harvested after being caged on Bolls (2 days) at levels reaching 103 and 104 colony forming units (cfus) per insect, respectively. However, Bolls caged with insects infected with Pa-1R or Kp 5-1R and with evidence of feeding did not become diseased nor were either opportunists detected from boll tissues. Insects infected with N. coryli transmitted the pathogen, which resulted in diseased Bolls and fungi concentrations reached 106 cfus/g locule tissue at 2 weeks following the caging period. Notably, each of the three pathogens independently caused boll disease when mechanically inoculated using a needle puncture. Generally, these results suggest that cotton pathogen acquisition by the SGSB was not sufficient to determine whether the insects were disease vectors of the opportunists.

  • temporal analysis of cotton boll symptoms resulting from southern green stink bug feeding and transmission of a bacterial pathogen
    Journal of Economic Entomology, 2009
    Co-Authors: Enrique Gino Medrano, Jesus F Esquivel, Robert L Nichols, Alois A Bell
    Abstract:

    The southern green stink bug, Nezara viridula (L.), is a significant pest of cotton, Gossypium hirsutum L., and is becoming an increasing challenge due to the decrease in use of broad-spectrum insecticides on the crop. The southern green stink bug can vector an opportunistic Pantoea agglomerans strain (designated Sc 1-R) into cotton Bolls, resulting in infection. The appearance of stink bug damage varies, and pest managers cannot readily identify its source. This research reports a systematic depiction of green, immature boll responses at various stages of maturity (1, 2, and 3 wk post-anthesis [WPA]) to stink bug injury and to infection by the vectored cotton pathogen by demonstrating the progression of effects 1, 2, and 3 wk after exposure (WAE). When laboratory-reared adult southern green stink bug not harboring Sc 1-R deposited bacteria into greenhouse-grown Bolls at 1, 2, or 3 WPA during feeding/probing, bacteria reached concentrations of 109, 109, and 103 colony-forming units (CFUs)/g tissue, respectively, at 3 WAE, yet caused minimal seed and lint damage regardless of the age of the Bolls that were penetrated. Bolls at a maturity of 1 or 2 WPA showed similar susceptibility when exposed to stink bugs that vectored Sc 1-R. After a week of infection, seeds were salmon-pink with normal white lint and up to 104 CFUs/g tissue when Sc 1-R was detected. Necrosis of the entire inoculated locule(s) with a maximum Sc 1-R concentration detected at 108 CFUs/g tissue occurred in samples harvested 2 or 3 WAE. Conversely, seed and lint deterioration due to the transmitted opportunist into Bolls exposed 3 WPA was confined to the puncture site. In summary, after a week of development, Bolls were tolerant to southern green stink bug feeding/ probing damage and to nonpathogenic bacteria, but they were severely damaged when the opportunistic pathogen Sc 1-R was transmitted. At 3 WPA, the fruit was immune to the spread of the pathogen with infections confined to the puncture site.

  • transmission of cotton seed and boll rotting bacteria by the southern green stink bug nezara viridula l
    Journal of Applied Microbiology, 2007
    Co-Authors: Jesus F Esquivel, Alois A Bell
    Abstract:

    Aims:  To determine the ability of the southern green stink bug (SGSB) (Nezara viridula L.) to transmit Pantoea agglomerans into cotton (Gossypium hirsutum) Bolls. Methods and Results:  An SGSB laboratory colony was kept on fresh green beans. A P. agglomerans variant resistant to rifampicin (Rif) (strain Sc 1-R) was used as the opportunistic cotton pathogen. Adult insects were individually provided green beans that were sterilized and then soaked in either sterile water or in a suspension of strain Sc 1-R. Insects were individually caged with an unopened greenhouse-grown cotton boll. After 2 days, live SGSB were collected, surfaced sterilized, ground, serially diluted, and then plated on nonselective media and media amended with Rif. Exterior and interior evidence of feeding on Bolls was recorded 2 weeks after exposure to insects. Seed and lint tissue were harvested, ground, serially diluted, and then plated on media with and without Rif. Bacteria were recovered on nonselective media from all insects, and from seed and lint with signs of insect feeding at concentrations ranging from 102 to 109 CFU g−1 tissue. The Sc 1-R strain was isolated only from insects exposed to the marked strain and from seed and lint of respective Bolls showing signs of insect feeding. Evidence of insect feeding on the exterior wall of the carpel was not always apparent (47%), whereas feeding was always observed (100%) on the interior wall in association with bacterial infections of seed and lint. Conclusions: Nezara viridula readily ingested the opportunistic P. agglomerans strain Sc 1-R and transmitted it into unopened cotton Bolls. Infections by the transmitted Sc 1-R strain caused rotting of the entire locule that masked internal carpel wounds incurred by insect feeding. Bacteria were recovered from penetration points by insects not exposed to the pathogen, but locule damage was limited to the area surrounding the feeding site (c. 3 mm). Significance and Impact of the Study:  This is the first study that demonstrates the ability of SGSB to acquire and transmit plant pathogenic bacteria into cotton Bolls.

Colodro Sainz Itziar - One of the best experts on this subject based on the ideXlab platform.

  • El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote)
    'Universitat Politecnica de Valencia', 2014
    Co-Authors: Colodro Sainz Itziar
    Abstract:

    El creciente urbanismo en zonas costeras, la contaminación marina y la explotación de los recursos han provocado, entre otras consecuencias, la eutrofización de las aguas. El Charco de San Ginés (Arrecife, Lanzarote) es un ecosistema singular sometido a lo largo de la historia a la presión antrópica devaluando su estado ecológico. En la actualidad, han proliferado unas bolas de algas, predominantemente Valonia aegagropila. En este contexto, se pretende realizar un estudio sobre el efecto depurativo que puedan tener estas bolas en la aguas del Charco de San Ginés. Para ello, el proyecto consiste en tres ensayos “ex situ”, que consistirán en la preparación de cilindros llenos de agua del Charco de San Ginés de un punto previamente seleccionado, unos con una bola de Valonia y otros, sin ninguna bola a modo de Control. Se realizarán extracciones periódicas aproximadamente a diferentes horas del día tanto de dentro como de fuera de la bola y así medir los nutrientes analíticamente. Se controlará el oxígeno disuelto, pH y temperatura. Los resultados obtenidos mostraron que según las dimensiones de cada bola y su relación con agua a tratar se pueden observar o no diferencias significativas en los tratamientos aplicabes para valorar su efecto como biofiltro en aguas marinas.The increasing urbanization in coastal areas, marine pollution and resource exploitation have led, among other consequences, the water eutrophication. El Charco de San Ginés (Arrecife, Lanzarote) is a unique ecosystem, under throughout history to human pressure devaluing its ecological status. Currently, they have proliferated balls of algae, predominantly Valonia aegagropila. In this context, we will do a study for evaluate the effect that may have these balls in the waters of the Charco de San Ginés. For this, the project consists of three "ex situ" tests, which include the preparation of cylinders whith water of a previously selected point in the Charco de San Ginés, some, with a ball of Valonia and others, without any ball as a Control. Periodic withdrawals will be made about different times of day both inside and outside the ball and thus measure the nutrients analytically. Dissolved oxygen, pH and temperature will be controlerl. The results showed that as the size of each ball and its relationship with water to be treated can be observed, signifcant or no significant differences in the treatments aplicabes to assess their effect as biofilter in seawater.Colodro Sainz, I. (2014). El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote). Universitat Politècnica de València. http://hdl.handle.net/10251/45137Archivo delegad

  • El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote)
    'Universitat Politecnica de Valencia', 2014
    Co-Authors: Colodro Sainz Itziar
    Abstract:

    El creciente urbanismo en zonas costeras, la contaminación marina y la explotación de los recursos han provocado, entre otras consecuencias, la eutrofización de las aguas. El Charco de San Ginés (Arrecife, Lanzarote) es un ecosistema singular sometido a lo largo de la historia a la presión antrópica devaluando su estado ecológico. En la actualidad, han proliferado unas bolas de algas, predominantemente Valonia aegagropila. En este contexto, se pretende realizar un estudio sobre el efecto depurativo que puedan tener estas bolas en la aguas del Charco de San Ginés. Para ello, el proyecto consiste en tres ensayos “ex situ”, que consistirán en la preparación de cilindros llenos de agua del Charco de San Ginés de un punto previamente seleccionado, unos con una bola de Valonia y otros, sin ninguna bola a modo de Control. Se realizarán extracciones periódicas aproximadamente a diferentes horas del día tanto de dentro como de fuera de la bola y así medir los nutrientes analíticamente. Se controlará el oxígeno disuelto, pH y temperatura. Los resultados obtenidos mostraron que según las dimensiones de cada bola y su relación con agua a tratar se pueden observar o no diferencias significativas en los tratamientos aplicabes para valorar su efecto como biofiltro en aguas marinas.The increasing urbanization in coastal areas, marine pollution and resource exploitation have led, among other consequences, the water eutrophication. El Charco de San Ginés (Arrecife, Lanzarote) is a unique ecosystem, under throughout history to human pressure devaluing its ecological status. Currently, they have proliferated balls of algae, predominantly Valonia aegagropila. In this context, we will do a study for evaluate the effect that may have these balls in the waters of the Charco de San Ginés. For this, the project consists of three "ex situ" tests, which include the preparation of cylinders whith water of a previously selected point in the Charco de San Ginés, some, with a ball of Valonia and others, without any ball as a Control. Periodic withdrawals will be made about different times of day both inside and outside the ball and thus measure the nutrients analytically. Dissolved oxygen, pH and temperature will be controlerl. The results showed that as the size of each ball and its relationship with water to be treated can be observed, signifcant or no significant differences in the treatments aplicabes to assess their effect as biofilter in seawater.Colodro Sainz, I. (2014). El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote). http://hdl.handle.net/10251/45137Archivo delegad

Jesus F Esquivel - One of the best experts on this subject based on the ideXlab platform.

  • relationship between piercing sucking insect control and internal lint and seed rot in southeastern cotton gossypium hirsutum l
    Journal of Economic Entomology, 2015
    Co-Authors: Enrique G Medrano, Jeremy K Greene, Jesus F Esquivel, Alois A Bell, Phillip M Roberts, J S Bacheler, James J Marois, David L Wright, Robert L Nichols, Sara E Duke
    Abstract:

    In 1999, crop consultants scouting for stink bugs (Hemiptera spp.) in South Carolina discovered a formerly unobserved seed rot of cotton that caused yield losses ranging from 10 to 15% in certain fields. The disease has subsequently been reported in fields throughout the southeastern Cotton Belt. Externally, diseased Bolls appeared undamaged; internally, green fruit contain pink to dark brown, damp, deformed lint, and necrotic seeds. In greenhouse experiments, we demonstrated transmission of the opportunistic bacterium Pantoea agglomerans by the southern green stink bug, Nezara viridula (L.). Here, green Bolls were sampled from stink bug management plots (insecticide protected or nontreated) from four South Atlantic coast states (North Carolina, South Carolina, Georgia, and Florida) to determine disease incidence in the field and its association with piercing-sucking insects feeding. A logistic regression analysis of the boll damage data revealed that disease was 24 times more likely to occur (P = 0.004) in Bolls collected from plots in Florida, where evidence of pest pressure was highest, than in Bolls harvested in NC with the lowest detected insect pressure. Fruit from plots treated with insecticide, a treatment which reduced transmission agent numbers, were 4 times less likely to be diseased than Bolls from unprotected sites (P = 0.002). Overall, punctured Bolls were 125 times more likely to also have disease symptoms than nonpunctured Bolls, irrespective of whether or not plots were protected with insecticides (P = 0.0001). Much of the damage to cotton Bolls that is commonly attributed to stink bug feeding is likely the resulting effect of vectored pathogens.

  • potential for nezara viridula hemiptera pentatomidae to transmit bacterial and fungal pathogens into cotton Bolls
    Current Microbiology, 2009
    Co-Authors: Enrique G Medrano, Jeremy K Greene, Jesus F Esquivel, Alois A Bell, Phillip M Roberts, J S Bacheler, James J Marois, David L Wright, Robert L Nichols, Juan D Lopez
    Abstract:

    Recently, we showed that the southern green stink bug (SGSB), Nezara viridula (L.), can transmit Pantoea agglomerans (Ewing and Fife), an opportunistic bacterium, into green cotton Bolls resulting in plant disease. Here, we hypothesized that our established model could be used to determine if the SGSB was a general, non-discriminate vector by using two other opportunistic bacterial pathogens of Bolls (Pantoea ananatis [Serano] and Klebsiella pneumoniae [Schroeter]) and the known fungal pathogen Nematospora coryli (Peglion). Variants of P. ananatis (strain Pa-1R) and K. pneumoniae (strain Kp 5-1R) selected for rifampicin (Rif) resistance were used as bacterial opportunists. N. coryli was detected only from laboratory-reared SGSB directly exposed to the fungus. Both Pa-1R and Kp 5-1R were recovered from SGSB previously provided a contaminated food source (2 days), sterile food (5 days), and then harvested after being caged on Bolls (2 days) at levels reaching 103 and 104 colony forming units (cfus) per insect, respectively. However, Bolls caged with insects infected with Pa-1R or Kp 5-1R and with evidence of feeding did not become diseased nor were either opportunists detected from boll tissues. Insects infected with N. coryli transmitted the pathogen, which resulted in diseased Bolls and fungi concentrations reached 106 cfus/g locule tissue at 2 weeks following the caging period. Notably, each of the three pathogens independently caused boll disease when mechanically inoculated using a needle puncture. Generally, these results suggest that cotton pathogen acquisition by the SGSB was not sufficient to determine whether the insects were disease vectors of the opportunists.

  • temporal analysis of cotton boll symptoms resulting from southern green stink bug feeding and transmission of a bacterial pathogen
    Journal of Economic Entomology, 2009
    Co-Authors: Enrique Gino Medrano, Jesus F Esquivel, Robert L Nichols, Alois A Bell
    Abstract:

    The southern green stink bug, Nezara viridula (L.), is a significant pest of cotton, Gossypium hirsutum L., and is becoming an increasing challenge due to the decrease in use of broad-spectrum insecticides on the crop. The southern green stink bug can vector an opportunistic Pantoea agglomerans strain (designated Sc 1-R) into cotton Bolls, resulting in infection. The appearance of stink bug damage varies, and pest managers cannot readily identify its source. This research reports a systematic depiction of green, immature boll responses at various stages of maturity (1, 2, and 3 wk post-anthesis [WPA]) to stink bug injury and to infection by the vectored cotton pathogen by demonstrating the progression of effects 1, 2, and 3 wk after exposure (WAE). When laboratory-reared adult southern green stink bug not harboring Sc 1-R deposited bacteria into greenhouse-grown Bolls at 1, 2, or 3 WPA during feeding/probing, bacteria reached concentrations of 109, 109, and 103 colony-forming units (CFUs)/g tissue, respectively, at 3 WAE, yet caused minimal seed and lint damage regardless of the age of the Bolls that were penetrated. Bolls at a maturity of 1 or 2 WPA showed similar susceptibility when exposed to stink bugs that vectored Sc 1-R. After a week of infection, seeds were salmon-pink with normal white lint and up to 104 CFUs/g tissue when Sc 1-R was detected. Necrosis of the entire inoculated locule(s) with a maximum Sc 1-R concentration detected at 108 CFUs/g tissue occurred in samples harvested 2 or 3 WAE. Conversely, seed and lint deterioration due to the transmitted opportunist into Bolls exposed 3 WPA was confined to the puncture site. In summary, after a week of development, Bolls were tolerant to southern green stink bug feeding/ probing damage and to nonpathogenic bacteria, but they were severely damaged when the opportunistic pathogen Sc 1-R was transmitted. At 3 WPA, the fruit was immune to the spread of the pathogen with infections confined to the puncture site.

  • transmission of cotton seed and boll rotting bacteria by the southern green stink bug nezara viridula l
    Journal of Applied Microbiology, 2007
    Co-Authors: Jesus F Esquivel, Alois A Bell
    Abstract:

    Aims:  To determine the ability of the southern green stink bug (SGSB) (Nezara viridula L.) to transmit Pantoea agglomerans into cotton (Gossypium hirsutum) Bolls. Methods and Results:  An SGSB laboratory colony was kept on fresh green beans. A P. agglomerans variant resistant to rifampicin (Rif) (strain Sc 1-R) was used as the opportunistic cotton pathogen. Adult insects were individually provided green beans that were sterilized and then soaked in either sterile water or in a suspension of strain Sc 1-R. Insects were individually caged with an unopened greenhouse-grown cotton boll. After 2 days, live SGSB were collected, surfaced sterilized, ground, serially diluted, and then plated on nonselective media and media amended with Rif. Exterior and interior evidence of feeding on Bolls was recorded 2 weeks after exposure to insects. Seed and lint tissue were harvested, ground, serially diluted, and then plated on media with and without Rif. Bacteria were recovered on nonselective media from all insects, and from seed and lint with signs of insect feeding at concentrations ranging from 102 to 109 CFU g−1 tissue. The Sc 1-R strain was isolated only from insects exposed to the marked strain and from seed and lint of respective Bolls showing signs of insect feeding. Evidence of insect feeding on the exterior wall of the carpel was not always apparent (47%), whereas feeding was always observed (100%) on the interior wall in association with bacterial infections of seed and lint. Conclusions: Nezara viridula readily ingested the opportunistic P. agglomerans strain Sc 1-R and transmitted it into unopened cotton Bolls. Infections by the transmitted Sc 1-R strain caused rotting of the entire locule that masked internal carpel wounds incurred by insect feeding. Bacteria were recovered from penetration points by insects not exposed to the pathogen, but locule damage was limited to the area surrounding the feeding site (c. 3 mm). Significance and Impact of the Study:  This is the first study that demonstrates the ability of SGSB to acquire and transmit plant pathogenic bacteria into cotton Bolls.

Mary D Sheridan - One of the best experts on this subject based on the ideXlab platform.

  • the stycar graded balls vision test
    Developmental Medicine & Child Neurology, 2008
    Co-Authors: Mary D Sheridan
    Abstract:

    UMMARY The origin and clinical application of the STYCAR graded-balls vision test are briefly described, together with clinical findings from tests applied to over 400 normal babies and children under the age of 2 1/2 years, and 850 handicapped children under 12 years of age. By relating ball sizes to Snellen letter equivalents, it has been possible to show that the normal visual acuity of 12-month-old infants is at least 3/9 3/9 (i.e. equivalent to 6/18 6/18), and is probably superior to this. RESUME Le test de vision STYCAR par balles graduees L'origine et les applications cliniques du test de vision STYCAR par balles graduees sont decrites brievement, ainsi que les precisions cliniques obtenues a partir des test appliques a plus de 400 nourrissons âges de moins de 2 1/2 ans et a 850 enfants handicapes de moins de 12 ans. En reliant la taille des balles aux lettres de Snellen equivalents, il a ete possible de montrer que l'acuite visuelle normale des nourrissons de 12 mois est au moins de 3/9 3/9 (c'est a dire equivalente a 6/18 6/18) et est probablement superieure. ZUSAMMENFASSUNG Der'STYCAR graded balls' Sehtest Uber den Ursprung und die klinische Anwendbarkeit des ‘STYCAR graded-balls’ Sehtest wird kurz berichtet. Gleichzeitig werden die Ergebnisse des Tests bei mehr als 400 normalen Sauglingen und Kleinkindern unter 2 1/2 Jahren, sowie bei 850 behinderten Kindern unter 12 Jahren beschrieben. Im Zusammenhang der Ball-grosen, die mit denen von Snellenletter ubereinstimmten, wurde eine normale Sehscharfe bei 12 Monate alten Kindern von wenigstens 3/9 3/9 (entsprechend 6/18 6/18) festgestellt die wahrscheinlich sogar noch daruber lag. RESUMEN El test de vision con bolas graduadas de STYCAR Se describe brevemente el origen y la aplicacion clinica del test de vision con bolas graduadas de STYCAR, y se dan tambien los hallazgos clinicos de la aplicacion del test a mas de 400 ninos normales de menos de 2 anos y medio de edad y 850 ninos minusvalidos de menos de 12 anos. Relacionando los tamanos de las bolas con los equivalentes de las letras Snellen, ha sido posible mostrar que la agudeza visual normal de ninos de 12 meses de edad es por lo menos 3/9 3/9 (equivalentes a 6/18 6/18) y muy probablemente superior a estas cifras.

Ochou, Ochou Germain - One of the best experts on this subject based on the ideXlab platform.

  • Caractéristiques de l’évolution spatio-temporelle de Thaumatotibia leucotreta Meyrick (Lepidoptera : Tortricidae) dans les zones de production cotonnière de Côte d’Ivoire
    'European Scientific Institute ESI', 2018
    Co-Authors: Ochou, Germain Elisabeth Cynthia, Kobenan, Koffi Christophe, Dekoula, Charles Sekpa, Kone, Pitou Woklin Euloge, Didi Roland, Kouakou Malanno, Bini, Kouadio Kra Norbert, Mamadou Dagnogo, Dick, Acka Emmanuel, Ochou, Ochou Germain
    Abstract:

    In order to update knowledge on the spatio-temporal evolution of Thaumatotibia leucotreta, the geographical areas and seasons of predilection of adult and larval populations have been studied in the last six years from 2012 to 2017. Monitoring of natural adult populations revealed that populations were more abundant in the southern cotton production area as compared to the north. A Monitoring of larval infestations showed that infestations occurred on cotton at the end of august (0.10 larvae/100 Bolls) and increased gradually during october-november (0.31 to 0.93 larvae/100 Bolls), indicating a strong relationship between evolution of adult and larval populations and cotton phenology. Early sowings exhibited higher infestation levels (0.87 larvae/100 Bolls). Annual variations of pest infestation levels increased from years to years, from 0.23 to 0.49 larvae/100 Bolls over the study period. Mapping the geographic distribution of infestations showed highest pest densities in the southern zone, mostly in surrounding areas of Boron (1.52 larvae/100 Bolls). With regard to the emerging status of T. leucotreta over recent years, the current pyrethroid resistance management strategy deserves to be improved on the basis of the pest geographic and seasonal profiles

  • Caractéristiques de l’évolution spatio-temporelle de Pectinophora gossypiella Saunders (Lepidoptera : Gelechiidae) dans les zones de production cotonnière de Côte d’Ivoire : Implications pour une stratégie de gestion optimale de la résistance aux pyréthrinoïdes
    'European Scientific Institute ESI', 2018
    Co-Authors: Ochou, Germain Elisabeth Cynthia, Kobenan, Koffi Christophe, Kone, Pitou Woklin Euloge, Didi Roland, Kouakou Malanno, Bini, Kouadio Kra Norbert, Mamadou Dagnogo, Dick, Acka Emmanuel, Ochou, Ochou Germain
    Abstract:

    In order to update knowledge on the spatio-temporal evolution of Pectinophora gossypiella, the geographical areas and the seasons of predilection of adult and larval populations have been studied in the last six years from 2012 to 2017. The study showed that adult populations are more abundant in the cotton production area of the South compared to the North. They have a very low activity during the intercropping season while the most important outbreaks occurred in October-December. The monitoring of larval populations carried out on farm scale showed that infestations started on cotton early August and increased until November, which leads to a strong relationship between the evolution of adult populations, larval infestations and cotton plant phenology. Late sowings D5 and D6 exhibited higher levels of infestation (0.50 to 0.80 larvae/100 Bolls) as compared to early sowing (0.21-0.31 larvae/100 Bolls). Annual variations of pest infestation levels increased from years to years, fluctuating from 0.14 to 0.95 larvae/100 Bolls over the study period. Mapping of the geographic distribution of infestation showed more severe pest pressure in the southern cotton areas, mostly in surrounding areas of Bouaké, Bouaflé, Séguéla and Boron (18,90; 5,33; 1,52; 1,06 larvae/100 Bolls respectively). With regard to the emerging status of P. gossypiella over recent years, the current pyrethroid resistance management strategy deserves to be improved on the basis of the pest geographic and seasonal profiles