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15 resultados encontrados para: AUTOR: Cave, Ronald D.
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1.
Artículo
*En hemeroteca, SIBE-Tapachula, Samples
The dynastine scarab beetles of Honduras, Nicaragua and El Salvador (Coleoptera: scarabaeidae: dynatinae)
Ratcliffe, Brett C. ; Cave, Ronald D. (coaut.) ;
Contenido en: Bulletin of the University of Nebraska State Museum Vol. 21, no. 1 (August 2006), p. 1-424
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
50455-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula, Samples

2.
- Artículo con arbitraje
*En hemeroteca, SIBE-Tapachula
Effect of weeds on insect pests of maize and their natural enemies in Southern Mexico
Penagos Torres, Dora Isabel ; Magallanes Cedeño, Ricardo (coaut.) ; Valle Mora, Javier Francisco (coaut.) ; Cisneros Hernández, Juan (coaut.) ; Martínez, A. M. (coaut.) ; Goulson, D. (coaut.) ; Chapman, Jason W. (coaut.) ; Caballero, P. (coaut.) ; Cave, Ronald D. (coaut.) ; Williams, Trevor (coaut.) ;
Contenido en: International Journal of Pest Management Vol. 49, no. 2 (Abril-June 2003), p. 155-161 ISSN: 0967-0874
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
B3103 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
Resumen en: Inglés |
Resumen en inglés

A pilot study performed on the Pacific coastal plain of Chiapas, Mexico, focused on the prevalence of maize crop infestation by insect pests, parasitism of pests and the abundance of insect predators in maize plots with weeds compared with plots under a regime of rigorous manual weed control. Sampling was conducted on four occasions at 20, 32, 44 and 56 days post-planting. Infestation of maize by fall armyworm larvae, Spodoptera frugiperda (Lepidoptera: Noctuidae), was more than twice as great in plots with strict weed control compared with weedy plots at 20 days post-planting, but declined thereafter in both treatments. The prevalence of aphid infestation and the abundance of nitidulid beetles were consistently greater in weed-controlled plots. In contrast, the density of beneficial predatory Coleoptera increased significantly in plots with weeds, and it is suggested that this probably explains the lower incidence of pests. S. frugiperda egg masses placed in experimental plots suffered a significantly higher incidence rate of parasitism by Chelonus insularis (Hymenoptera: Braconidae) in clean plots (42.0%) compared with those placed in weedy plots (3.75%); it is suspected that weeds may hinder the location of egg masses by parasitoids. Overall, the presence or absence of weeds had a marked influence on the arthropod community present in maize fields. The weeds did not affect maize plant height, the levels of plant damage or the yield of grain from plants under each type of weed regime, implying that competitive effects of weeds may be offset by greater numbers of beneficial insects in weedy plots. Our pilot study indicates that strict weed control in maize may be unnecessary.


3.
- Artículo con arbitraje
*En hemeroteca, SIBE-Tapachula
Impact of a nucleopolyhedrovirus bioinsecticide and selected synthetic insecticides on the abundance of insect natural enemies on maize in southern Mexico
Armenta, R. ; Martínez, A. M. (coaut.) ; Chapman, Jason W. (coaut.) ; Magallanes Cedeño, Ricardo (coaut.) ; Goulson, D. (coaut.) ; Caballero, P. (coaut.) ; Cave, Ronald D. (coaut.) ; Cisneros, J. (coaut.) ; Valle Mora, Javier Francisco (coaut.) ; Castillejos Puón, Vasty (coaut.) ; Penagos Torres, Dora Isabel (coaut.) ; García, L. F. (coaut.) ; Williams, Trevor (coaut.) ;
Contenido en: Journal of Economic Entomology Vol. 96, no. 3 (June 2003), p. 649-661 ISSN: 0022-0493
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
B3099 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
PDF
Resumen en: Inglés |
Resumen en inglés

The impact of commonly used organophosphate (chlorpyrifos, methamidophos), carbamate (carbaryl), and pyrethroid (cypermethrin) insecticides on insect natural enemies was compared with that of a nucleopolyhedrovirus (Baculoviridae) of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in maize grown in southern Mexico. Analyses of theSELECTVand Koppert Side Effects (IOBC) databases on the impact of synthetic insecticides on arthropod natural enemies were used to predict 75Ð90% natural enemy mortality after application, whereas the bioinsecticide was predicted to have no effect. Three Þeld trails were performed in mid- and late-whorl stage maize planted during the growing season in Chiapas State, Mexico. Synthetic insecticides were applied at product label recommended rates using a manual knapsack sprayer Þtted with a cone nozzle. The biological pesticide was applied at a rate of 3 1012 occlusion bodies (OBs)/ha using identical equipment. Pesticide impacts on arthropods on maize plants were quantiÞed at intervals between 1 and 22 d postapplication. The biological insecticide based on S. frugiperda nucleopolyhedrovirus had no adverse effect on insect natural enemies or other nontarget insect populations. Applications of the carbamate, pyrethroid, and organophosphate insecticides all resulted in reduced abundance of insect natural enemies, but for a relatively short period (8Ð15 d). Pesticide applications made to late-whorl stage maize resulted in lesser reductions in natural enemy populations than applications made at the mid-whorl stage, probably because of a greater abundance of physical refuges and reduced spray penetration of late-whorl maize.


4.
- Artículo con arbitraje
*En hemeroteca, SIBE-Tapachula
Formulation of a Nucleopolyhedrovirus with boric acid for control of Spodoptera frugiperda (Lepidoptera: noctuidae) in maize
Cisneros Hernández, Juan (autor) ; Pérez, José Angel (autor) ; Penagos Torres, Dora Isabel (autor) ; Goulson, Dave (autor) ; Caballero, Primitivo (autor) ; Cave, Ronald D. (autor) ; Williams, Trevor (autor) ;
Clasificación: AR/633.1599 / F6
Contenido en: Biological Control Vol. 23, no. 1 (January 2002), p. 87-95 ISSN: 1049-9644
Bibliotecas: Campeche , San Cristóbal , Tapachula
Cerrar
SIBE Campeche
ECO040006393 (Disponible) , ECO040003370 (Disponible)
Disponibles para prestamo: 2
Cerrar
SIBE San Cristóbal
ECO010005485 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
33926-40 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
Resumen en: Inglés |
Resumen en inglés

The degree of control of the fall armyworm, Spodoptera frugiperda, by a multiple nucleopolyhedrovirus (SfMNPV) appears to be limited by the quantity of inoculum consumed by the insect and the delivery of the virus to the insect feeding site. The formulation of the virus with phagostimulants and/or viral synergists, such as boric acid, may help overcome this problem. The present study aimed to determine the degree of potentiation of boric acid toward SfMNPV in a granular phagostimulant formulation. In a laboratory bioassay the LC50 value for second-instar larvae was reduced from 114 virus occlusion bodies (OBs)/mm2 of diet surface for virus alone to 51 OBs/mm2 of diet in the presence of 1% boric acid. The mean time to death of larvae exposed to virus mixed with 0.5 or 1% boric acid was not significantly different from that of larvae inoculated with virus alone. Increasing the concentration of boric acid at a single determined concentration of virus (80 OBs/mm2) resulted in a significant increase in the prevalence of virus-induced mortality. The boric acid alone did not cause S. frugiperda mortality at the concentrations tested. A field trial performed with S. frugiperda larvae held on plants within fine gauze bags indicated that application of maize flour granules containing virus + 1% boric acid caused a significant increase in virus-induced mortality compared to application of granules containing virus alone.

A randomized block experiment performed later also resulted in a higher prevalence of virus-induced mortality in S. frugiperda larvae exposed to virus mixed with 1% boric acid in samples collected at 5 days postapplication and reared in the laboratory until death or pupation, but not in samples made at 1 day and 3 days postapplication. Differences in the prevalence of virus infection in insects collected at each time point may have been related to the consistency of the granular formulation, which turned into a paste and adhered to the surface of maize plants under conditions of heavy rainfall. Granules containing 1 and 4% boric acid were not toxic to the earwig, Doru taeniatum, in the laboratory. The same concentrations of boric acid sprayed onto maize plants did not significantly reduce the abundance of natural enemies or other nontarget insects at any sample time point. Boric acid offers an economical means of enhancing baculovirus activity with little apparent risk to nontarget arthropods.


5.
Artículo
Consequences of interspecific competition on the virulence and genetic composition of a nucleopolyhedrovirus in spodoptera frugiperda larvae parasitized by chelonus insularis
Escribano, Ana ; Williams, Trevor (coaut.) ; Goulson, David (coaut.) ; Cave, Ronald D. (coaut.) ; Chapman, Jason W. (coaut.) ; Caballero, P. (coaut.) ;
Clasificación: AR/633.1599 / C6
Contenido en: Biocontrol Science and Technology No. 11 (2001), p. 649-662 ISSN: 0958-3157
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
ECO020008366 (Disponible)
Disponibles para prestamo: 1

6.
Artículo
PDF PDF
Resumen en: Inglés |
Resumen en inglés

The incidence of cannibalism of larval Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize under field conditions was investigated using field cages. Cannibalism was found to account for approximately 40% mortality when maize plants were infested with two or four fourth-instar larvae over a 3-day period. Field trials examined the effect of larval density on the prevalence of natural enemies of S. frugiperda. The abundance of predators (earwigs, staphylinids, other predatory beetles, and Chrysoperla spp.) was significantly greater on maize plants with higher levels of larval feeding damage, while the relationship between predator abundance and number of S. frugiperda larvae per plant was less clear. As larval damage is probably a more reliable indicator of previous larval density than numbers collected at an evaluation, this indicates that predation risk will be greater for larvae living in large groups. Parasitism accounted for 7.1% mortality of larvae in sorghum, and involved six species of Hymenoptera and Tachinidae. There was no effect of larval density or within-plant distribution on the probability of larval attack by parasitoids. The selective benefits of cannibalism, in relation to the risk of predation and parasitism, are discussed.


7.
Artículo
Resumen en: Inglés |
Resumen en inglés

We evaluated the consequences of parasitism by the solitary ichneumonid endoparasitoid Campoletis sonorensis (Cameron) towards the replication, genetic composition and virulence of a nucleopolyhedrovirus (Baculoviridae) originating from Spodoptera frugiperda (J. E. Smith) larvae. Parasitism by C. sonorensis and viral infection of third and fourth instar S. frugiperda larvae resulted in reduced growth compared with nonparasitized control larvae. A positive correlation was observed between virus yield and larval instar at the moment of infection. When larvae were virus-inoculated in the fourth instar, parasitism resulted in a significant reduction in mean per capita virus yield compared to the virus yield from nonparasitized larvae. In an experiment involving 10 serial passages of virus in both parasitized and nonparasitized larvae, restriction endonuclease analysis of viral DNA amplified in nonparasitized larvae revealed the presence of the wild-type virus as well as three additional variants (A, B, and C) diagnosed by the presence of novel submolar PstI fragments of different sizes. In contrast, analysis of viral DNA from parasitized larvae showed the presence of the wild-type virus and two other variants (E and F), each characterized by a different submolar BglII fragment. Southern blot analysis indicated that the submolar fragments of variants E and F contained sequences originating from the viral genome. Bioassay of the different virus variants in S. frugiperda larvae indicated that their virulence was equal or less than that of the wild-type virus.We conclude that parasitism can affect the quantity of virus produced in dually infected and parasitized larvae, but no adverse effects were detected in terms of the biological activity of the virus.


8.
- Artículo con arbitraje
*En hemeroteca, SIBE-Tapachula
Is it feasible to use optical brightener technology with a baculovirus bioinsecticide for resource-poor maize farmers in Mesoamerica?
Martínez, Ana Mabel ; Goulson, Dave (coaut.) ; Chapman, Jason W. (coaut.) ; Caballero, Primitivo (coaut.) ; Cave, Ronald D. (coaut.) ; Williams, Trevor (coaut.) ;
Clasificación: AR/633.1599 / I8
Contenido en: Biological Control Vol. 17, no. 2 (February 2000), p. 174-181 ISSN: 1049-9644
Bibliotecas: Campeche , San Cristóbal , Tapachula
Cerrar
SIBE Campeche
ECO040006675 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010004691 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
B3326 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
Resumen en: Inglés |
Resumen en inglés

Stilbene-derived optical brighteners greatly enhance the infectivity of a number of baculoviruses. This technology has been patented for use with insect pathogenic viruses in the United States and Canada. A baculovirus is currently being tested for its potential as a biological insecticide of Spodoptera frugiperda (Lepidoptera: Noctuidae), the principal insect pest of maize in Mesoamerica. A multiply embedded nucleopolyhedrovirus isolate originally from Nicaragua was bioassayed alone and in the presence of the optical brightener Tinopal LPW (1%), using second instar S. frugiperda larvae. The LC50 value of the virus alone was calculated at 82.1 polyhedral inclusion bodies (PIBs)/mm2 of diet compared with 0.71 PIBs/mm2 in the presence of Tinopal LPW. In contrast to other studies, the mean time to death of larvae exposed to virus and Tinopal LPW was significantly extended compared to larvae inoculated with virus alone.

Analysis of the results of eight independent field trials in Mexico and Honduras revealed a significant positive relationship between log virus dose and percentage mortality observed in S. frugiperda larvae. Virus-induced mortality was approximately 50% at the highest application rate tested: 1000 larval equivalents (LE) of virus/ha. When the impact of parasitism was taken into account, larval mortality increased to 45.0–90.7% in plots treated with virus at 250 LE/ha or more. A cost analysis indicated that approximately 60% pest control can be achieved as a conservative estimate with virus application and the action of parasitoids for the price of a chemical insecticide. Formulating the virus with an optical brightener appears to be an attractive option based on laboratory findings but requires field testing. The use of optical brightener technology will probably be feasible for maize growers in Mesoamerica only if it is highly effective at very low concentrations (<0.1%) or the volume of the virus application can be reduced.


9.
Artículo
*En hemeroteca, SIBE-Tapachula
Parasitoid-pathogen-pest interactions of chelonus insularis, campoletis sonorensis, and a nucleopolyhedrovirus in spodoptera frugiperda larvae
Escribano, Ana ; Williams, Trevor (coaut.) ; Goulson, David (coaut.) ; Cave, Ronald D. (coaut.) ; Caballero, Primitivo (coaut.) ;
Clasificación: AR/633.1599 / P3
Contenido en: Biological Control Vol. 19, no. 3 (November 2000), p. 265-273 ISSN: 1049-9644
Bibliotecas: San Cristóbal , Tapachula
Cerrar
SIBE San Cristóbal
ECO010004690 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
B3324 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Tapachula
Resumen en: Inglés |
Resumen en inglés

In this study we examined interactions between two solitary endoparasitoids, the braconid Chelonus insularis and the ichneumonid Campoletis sonorensis, and a multiple-enveloped nucleopolyhedrovirus infecting Spodoptera frugiperda larvae. We examined whether ovipositing females minimize interference by discriminating amongst hosts and examined the outcome of within-host competition between parasitoid species and between the parasitoids and the virus. The egg–larval parasitoid Ch. insularis did not discriminate between virus-contaminated and uncontaminated S. frugiperda eggs; all S. frugiperda larvae that emerged from surface-contaminated eggs died of viral infection prior to parasitoid emergence. The larval parasitoid C. sonorensis also failed to discriminate between healthy and virus-infected S. frugiperda larvae or between larvae unparasitized or parasitized by Ch. insularis. Host larvae parasitized in the egg stage by Ch. insularis were suitable for the development of C. sonorensis when they were multiparasitized by C. sonorensis as first, second, third, and fourth instars, whereas emergence of Ch. insularis was dramatically reduced (by 85 to 100%) in multiparasitized hosts. Nonspecific host mortality was significantly higher in multiparasitized hosts than in singly parasitized hosts.

The development time and sex ratio of C. sonorensis in multiparasitized host larvae were unaffected by the presence of Ch. insularis larval stages. Both Ch. insularis parasitized and nonparasitized larvae of the same instar (second, third, or fourth instars) had a similar quantitative response to a challenge of virus inoculum. All host larvae that ingested a lethal dose of virus were unsuitable for Ch. insularis development. In contrast, C. sonorensis did not survive in hosts that ingested a lethal virus dose immediately after parasitism, but parasitoid survival was possible with a 2-day delay between parasitism and viral infection and the percentage of parasitoid emergence increased significantly as the interval between parasitism and viral infection increased. The development time of C. sonorensis was significantly reduced in virus-infected hosts compared to conspecifics that developed in healthy hosts. C. sonorensis females that oviposited in virus-infected hosts did not transmit the virus to healthy hosts that were parasitized subsequently. Field applications of virus for biocontrol of S. frugiperda may lead to substantial mortality of immature parasitoids, although field experiments have not yet demonstrated such an effect.


10.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Parasitoid–pathogen–pest interactions of chelonus insularis, campoletis sonorensis, and a nucleopolyhedrovirus in spodoptera frugiperda larvae
Escribano, Ana (autora) ; Williams, Trevor (autor) ; Goulson, Dave (autor) ; Cave, Ronald D. (autor) ; Caballero Murillo, Primitivo (autor) ;
Disponible en línea
Contenido en: Biological Control Vol. 19, no. 3 (Noviembre 2000), p. 265-273 ISSN: 1049-9644
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

In this study we examined interactions between two solitary endoparasitoids, the braconid Chelonus insularis and the ichneumonid Campoletis sonorensis, and a multiple-enveloped nucleopolyhedrovirus infecting Spodoptera frugiperda larvae. We examined whether ovipositing females minimize interference by discriminating amongst hosts and examined the outcome of within-host competition between parasitoid species and between the parasitoids and the virus. The egg– larval parasitoid Ch. insularis did not discriminate between virus-contaminated and uncontaminated S. frugiperda eggs; all S. frugiperda larvae that emerged from surface-contaminated eggs died of viral infection prior to parasitoid emergence. The larval parasitoid C. sonorensis also failed to discriminate between healthy and virus-infected S. frugiperda larvae or between larvae unparasitized or parasitized by Ch. insularis. Host larvae parasitized in the egg stage by Ch. insularis were suitable for the development of C. sonorensis when they were multiparasitized by C. sonorensis as first, second, third, and fourth instars, whereas emergence of Ch. insularis was dramatically reduced (by 85 to 100%) in multiparasitized hosts. Nonspecific host mortality was significantly higher in multiparasitized hosts than in singly parasitized hosts.

The development time and sex ratio of C. sonorensis in multiparasitized host larvae were unaffected by the presence of Ch. insularis larval stages. Both Ch. insularis parasitized and nonparasitized larvae of the same instar (second, third, or fourth instars) had a similar quantitative response to a challenge of virus inoculum. All host larvae that ingested a lethal dose of virus were unsuitable for Ch. insularis development. In contrast, C. sonorensis did not survive in hosts that ingested a lethal virus dose immediately after parasitism, but parasitoid survival was possible with a 2-day delay between parasitism and viral infection and the percentage of parasitoid emergence increased significantly as the interval between parasitism and viral infection increased. The development time of C. sonorensis was significantly reduced in virus-infected hosts compared to conspecifics that developed in healthy hosts. C. sonorensis females that oviposited in virus-infected hosts did not transmit the virus to healthy hosts that were parasitized subsequently. Field applications of virus for biocontrol of S. frugiperda may lead to substantial mortality of immature parasitoids, although field experiments have not yet demonstrated such an effect.