The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

David J. Thompson - One of the best experts on this subject based on the ideXlab platform.

  • Parasitism of baculovirus-infected Plodia interpunctella by Venturia canescens and subsequent virus transmission
    Functional Ecology, 1996
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey
    Abstract:

    1. When parasitoids and pathogens compete for the same host there are often severe costs to the parasitoid. Wasps might be expected, then, to avoid parasitizing pathogen-infected hosts. 2. When the solitary endoparasitoid Venturia canescens was presented with healthy and granulosis virus-infected larvae of the Indian Meal Moth Plodia interpunctella, it did not exhibit any difference in contact or probing behaviour between healthy and infected hosts. 3. However, oviposition behaviour was influenced by the level of infection, with a significant reduction in the number of eggs laid in heavily infected hosts. 4. Transmission of the pathogen did not occur directly through oviposition. However, transmission through contamination of the environment by the parasitoid following oviposition in infected hosts was demonstrated.

  • transmission dynamics of bacillus thuringiensis infecting Plodia interpunctella a test of the mass action assumption with an insect pathogen
    Proceedings of The Royal Society B: Biological Sciences, 1996
    Co-Authors: Robert J Knell, Michael Begon, David J. Thompson
    Abstract:

    Central to theoretical studies of host-pathogen population dynamics is a term describing transmission of the pathogen. This usually assumes that transmission is proportional to the density of infectious hosts or particles and of susceptible individuals. We tested this assumption with the bacterial pathogen Bacillus thuringiensis infecting larvae of Plodia interpunctella , the Indian meal moth. Transmission was found to increase in a more than linear way with host density in fourth and fifth instar P. interpunctella , and to decrease with the density of infectious cadavers in the case of fifth instar larvae. Food availability was shown to play an important part in this process. Therefore, on a number of counts, the usual assumption was found not to apply in our experimental system.

  • Host behaviour and its influence on foraging and acceptance by the solitary parasitoid wasp, Venturia canescens (Hym.: Ichneumonidae)
    Entomophaga, 1995
    Co-Authors: Jeffrey A. Harvey, David J. Thompson
    Abstract:

    Behavioural interactions between the solitary koinobiont parasitoid,Venturia canescens, and two of its hosts,Plodia interpunctella andCorcyra cephalonica, were investigated.

  • The effect of host nutrition on growth and development of the parasitoid wasp Venturia canescens
    Entomologia Experimentalis et Applicata, 1995
    Co-Authors: Jeffrey A. Harvey, Ian F. Harvey, David J. Thompson
    Abstract:

    We investigated the effect of host (Plodia interpunctella ; Lepidoptera : Pyralidae) nutritional status on development of the solitary endoparasitoid, Venturia canescens (Hymenoptera : Ichneumonidae). Parasitoids from 3rd (L3) instars reared on a deficient diet during early parasitism took longer to develop and suffered higher mortality than those reared from hosts fed ad libitum although there was not a significant difference in the size of eclosing wasps from the two groups. L5 hosts reared at high density produced smaller parasitoids, which developed more rapidly than those reared from hosts from low density containers, although mortality was higher in the latter. In a separate experiment we starved groups of 10-20 hosts (parasitized as L3) daily beginning on the 4th day after parasitism, to determine the host developmental stage required for successful parasitoid development to eclosion. Parasitoid survivorship increased with length of host access to food, while the egg-to-adult parasitoid development time increased throughout the experiment. Parasitoid size decreased with increasing periods of host starvation. The successful emergence of Venturia depends upon Plodia reaching the size normally attained in the mid-5th instar, or 50-70% of the mass of healthy late 5th instars. Our results show that when earlier instars are parasitized, host growth is essential for successful parasitoid development to eclosion. Furthermore, they suggest that, for many koinobionts, host suitability may be greatly influenced by feeding rate and food quality.

  • Venturia canescens parasitizing Plodia interpunctella: host vulnerability - a matter of degree
    Ecological Entomology, 1995
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey, R. A. Andreev, R. D. Swain
    Abstract:

    Theoretical studies have established clearly that age- dependence in the association between parasitoids and hosts (and predators and prey generally), including age- dependence in the susceptibility of hosts to attack, is of potentially great importance as an influence on the dynamics of their populations (Godfray

Michael Begon - One of the best experts on this subject based on the ideXlab platform.

  • Parasitism of baculovirus-infected Plodia interpunctella by Venturia canescens and subsequent virus transmission
    Functional Ecology, 1996
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey
    Abstract:

    1. When parasitoids and pathogens compete for the same host there are often severe costs to the parasitoid. Wasps might be expected, then, to avoid parasitizing pathogen-infected hosts. 2. When the solitary endoparasitoid Venturia canescens was presented with healthy and granulosis virus-infected larvae of the Indian Meal Moth Plodia interpunctella, it did not exhibit any difference in contact or probing behaviour between healthy and infected hosts. 3. However, oviposition behaviour was influenced by the level of infection, with a significant reduction in the number of eggs laid in heavily infected hosts. 4. Transmission of the pathogen did not occur directly through oviposition. However, transmission through contamination of the environment by the parasitoid following oviposition in infected hosts was demonstrated.

  • transmission dynamics of bacillus thuringiensis infecting Plodia interpunctella a test of the mass action assumption with an insect pathogen
    Proceedings of The Royal Society B: Biological Sciences, 1996
    Co-Authors: Robert J Knell, Michael Begon, David J. Thompson
    Abstract:

    Central to theoretical studies of host-pathogen population dynamics is a term describing transmission of the pathogen. This usually assumes that transmission is proportional to the density of infectious hosts or particles and of susceptible individuals. We tested this assumption with the bacterial pathogen Bacillus thuringiensis infecting larvae of Plodia interpunctella , the Indian meal moth. Transmission was found to increase in a more than linear way with host density in fourth and fifth instar P. interpunctella , and to decrease with the density of infectious cadavers in the case of fifth instar larvae. Food availability was shown to play an important part in this process. Therefore, on a number of counts, the usual assumption was found not to apply in our experimental system.

  • Venturia canescens parasitizing Plodia interpunctella: host vulnerability - a matter of degree
    Ecological Entomology, 1995
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey, R. A. Andreev, R. D. Swain
    Abstract:

    Theoretical studies have established clearly that age- dependence in the association between parasitoids and hosts (and predators and prey generally), including age- dependence in the susceptibility of hosts to attack, is of potentially great importance as an influence on the dynamics of their populations (Godfray

  • long term population dynamics of the indian meal moth Plodia interpunctella and its granulosis virus
    Journal of Animal Ecology, 1994
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson
    Abstract:

    1. Theoretical studies suggest that disease may play an important role in the population dynamics of insects, but there have been no long-term empirical studies that have examined this interaction in the absence of other important biotic and abiotic factors. 2. In the laboratory, three virus-free (VF) populations of Plodia interpunctella were compared with three virus-infected (VI) populations that were continuously exposed to a granulosis virus. Data sets lasted for between 10 and 17 generations. Census data of dead adults were collected twice weekly and spectral analysis of the data was used to complement the observed population fluctuations

  • the effects of a sublethal baculovirus infection in the indian meal moth Plodia interpunctella
    Journal of Animal Ecology, 1994
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson
    Abstract:

    1. Baculoviruses are often highly pathogenic to their insect hosts, but theoretical studies have shown that sublethal infections may also play an important role in host population dynamics. Previous experiments have suggested that deleterious effects are caused by sublethal infections in a number of host-pathogen interactions, but these studies have been criticized on the basis of the methodology used. 2. Using an improved bioassay technique, the dose- and age-dependent response of the Indian meal moth, Plodia interpunctella, to sublethal levels of its granulosis virus was investigated. For the first time, significant sublethal effects have been unequivocally demonstrated in the development rate and reproductive capacity of the host

Steven M. Sait - One of the best experts on this subject based on the ideXlab platform.

  • Parasitism of baculovirus-infected Plodia interpunctella by Venturia canescens and subsequent virus transmission
    Functional Ecology, 1996
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey
    Abstract:

    1. When parasitoids and pathogens compete for the same host there are often severe costs to the parasitoid. Wasps might be expected, then, to avoid parasitizing pathogen-infected hosts. 2. When the solitary endoparasitoid Venturia canescens was presented with healthy and granulosis virus-infected larvae of the Indian Meal Moth Plodia interpunctella, it did not exhibit any difference in contact or probing behaviour between healthy and infected hosts. 3. However, oviposition behaviour was influenced by the level of infection, with a significant reduction in the number of eggs laid in heavily infected hosts. 4. Transmission of the pathogen did not occur directly through oviposition. However, transmission through contamination of the environment by the parasitoid following oviposition in infected hosts was demonstrated.

  • Venturia canescens parasitizing Plodia interpunctella: host vulnerability - a matter of degree
    Ecological Entomology, 1995
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey, R. A. Andreev, R. D. Swain
    Abstract:

    Theoretical studies have established clearly that age- dependence in the association between parasitoids and hosts (and predators and prey generally), including age- dependence in the susceptibility of hosts to attack, is of potentially great importance as an influence on the dynamics of their populations (Godfray

  • long term population dynamics of the indian meal moth Plodia interpunctella and its granulosis virus
    Journal of Animal Ecology, 1994
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson
    Abstract:

    1. Theoretical studies suggest that disease may play an important role in the population dynamics of insects, but there have been no long-term empirical studies that have examined this interaction in the absence of other important biotic and abiotic factors. 2. In the laboratory, three virus-free (VF) populations of Plodia interpunctella were compared with three virus-infected (VI) populations that were continuously exposed to a granulosis virus. Data sets lasted for between 10 and 17 generations. Census data of dead adults were collected twice weekly and spectral analysis of the data was used to complement the observed population fluctuations

  • the effects of a sublethal baculovirus infection in the indian meal moth Plodia interpunctella
    Journal of Animal Ecology, 1994
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson
    Abstract:

    1. Baculoviruses are often highly pathogenic to their insect hosts, but theoretical studies have shown that sublethal infections may also play an important role in host population dynamics. Previous experiments have suggested that deleterious effects are caused by sublethal infections in a number of host-pathogen interactions, but these studies have been criticized on the basis of the methodology used. 2. Using an improved bioassay technique, the dose- and age-dependent response of the Indian meal moth, Plodia interpunctella, to sublethal levels of its granulosis virus was investigated. For the first time, significant sublethal effects have been unequivocally demonstrated in the development rate and reproductive capacity of the host

Jeffrey A. Harvey - One of the best experts on this subject based on the ideXlab platform.

  • Parasitism of baculovirus-infected Plodia interpunctella by Venturia canescens and subsequent virus transmission
    Functional Ecology, 1996
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey
    Abstract:

    1. When parasitoids and pathogens compete for the same host there are often severe costs to the parasitoid. Wasps might be expected, then, to avoid parasitizing pathogen-infected hosts. 2. When the solitary endoparasitoid Venturia canescens was presented with healthy and granulosis virus-infected larvae of the Indian Meal Moth Plodia interpunctella, it did not exhibit any difference in contact or probing behaviour between healthy and infected hosts. 3. However, oviposition behaviour was influenced by the level of infection, with a significant reduction in the number of eggs laid in heavily infected hosts. 4. Transmission of the pathogen did not occur directly through oviposition. However, transmission through contamination of the environment by the parasitoid following oviposition in infected hosts was demonstrated.

  • Host behaviour and its influence on foraging and acceptance by the solitary parasitoid wasp, Venturia canescens (Hym.: Ichneumonidae)
    Entomophaga, 1995
    Co-Authors: Jeffrey A. Harvey, David J. Thompson
    Abstract:

    Behavioural interactions between the solitary koinobiont parasitoid,Venturia canescens, and two of its hosts,Plodia interpunctella andCorcyra cephalonica, were investigated.

  • The effect of host nutrition on growth and development of the parasitoid wasp Venturia canescens
    Entomologia Experimentalis et Applicata, 1995
    Co-Authors: Jeffrey A. Harvey, Ian F. Harvey, David J. Thompson
    Abstract:

    We investigated the effect of host (Plodia interpunctella ; Lepidoptera : Pyralidae) nutritional status on development of the solitary endoparasitoid, Venturia canescens (Hymenoptera : Ichneumonidae). Parasitoids from 3rd (L3) instars reared on a deficient diet during early parasitism took longer to develop and suffered higher mortality than those reared from hosts fed ad libitum although there was not a significant difference in the size of eclosing wasps from the two groups. L5 hosts reared at high density produced smaller parasitoids, which developed more rapidly than those reared from hosts from low density containers, although mortality was higher in the latter. In a separate experiment we starved groups of 10-20 hosts (parasitized as L3) daily beginning on the 4th day after parasitism, to determine the host developmental stage required for successful parasitoid development to eclosion. Parasitoid survivorship increased with length of host access to food, while the egg-to-adult parasitoid development time increased throughout the experiment. Parasitoid size decreased with increasing periods of host starvation. The successful emergence of Venturia depends upon Plodia reaching the size normally attained in the mid-5th instar, or 50-70% of the mass of healthy late 5th instars. Our results show that when earlier instars are parasitized, host growth is essential for successful parasitoid development to eclosion. Furthermore, they suggest that, for many koinobionts, host suitability may be greatly influenced by feeding rate and food quality.

  • Venturia canescens parasitizing Plodia interpunctella: host vulnerability - a matter of degree
    Ecological Entomology, 1995
    Co-Authors: Steven M. Sait, Michael Begon, David J. Thompson, Jeffrey A. Harvey, R. A. Andreev, R. D. Swain
    Abstract:

    Theoretical studies have established clearly that age- dependence in the association between parasitoids and hosts (and predators and prey generally), including age- dependence in the susceptibility of hosts to attack, is of potentially great importance as an influence on the dynamics of their populations (Godfray

Jeffrey A Fabrick - One of the best experts on this subject based on the ideXlab platform.

  • RNAi-induced silencing of embryonic tryptophan oxygenase in the Pyralid moth, Plodia interpunctella
    Journal of Insect Science, 2004
    Co-Authors: Jeffrey A Fabrick, Michael R Kanost, James E. Baker
    Abstract:

    Gene silencing through the introduction of double-stranded RNA (RNA interference, RNAi) provides a powerful tool for the elucidation of gene function in many systems, including those where genomics and proteomics are incomplete. The use of RNAi technology for gene silencing in Lepidoptera has lacked significant attention compared to other systems. To demonstrate that RNAi can be utilized in the lepidopteran, Plodia interpunctella, we cloned a cDNA for tryptophan oxygenase, and showed that silencing of tryptophan oxygenase through RNAi during embryonic development resulted in loss of eye-color pigmentation. The complete amino acid sequence of Plodia tryptophan oxygenase can be accessed through NCBI Protein Database.

  • rnai induced silencing of embryonic tryptophan oxygenase in the pyralid moth Plodia interpunctella
    Journal of Insect Science, 2004
    Co-Authors: Michael R Kanost, Jeffrey A Fabrick, James E. Baker
    Abstract:

    Abstract Gene silencing through the introduction of double-stranded RNA (RNA interference, RNAi) provides a powerful tool for the elucidation of gene function in many systems, including those where genomics and proteomics are incomplete. The use of RNAi technology for gene silencing in Lepidoptera has lacked significant attention compared to other systems. To demonstrate that RNAi can be utilized in the lepidopteran, Plodia interpunctella, we cloned a cDNA for tryptophan oxygenase, and showed that silencing of tryptophan oxygenase through RNAi during embryonic development resulted in loss of eye-color pigmentation. The complete amino acid sequence of Plodia tryptophan oxygenase can be accessed through NCBI Protein Database under NCBI Accession # AY427951. RNAi RNA interference PCR polymerase chain reaction RT-PCR reverse transcription-PCR