13 research outputs found

    The effect of day of emergence from the insect cadaver on the behaviour and environmental tolerances of infective juveniles of the entomopathogenic nematode Heterorhabditis Megidis (Strain UK211)

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    Infective juveniles (Us) of entomopathogenic nematodes (EPNs) are obligate parasites of insect larvae. Inside the host they develop into sexually mature adult stages and complete their life cycle. Two or 3 adult nematode generations can occur in the insect host. The increase in nematode population density in the insect cadaver, together with limiting nutrient conditions, result in the formation of IJs. These IJs emerge into the soil to search for a new host. It typically takes 7-8 days for all Us to emerge from a parasitized insect. We have investigated the effect of the day of emergence of Us from insect cadavers on the environmental tolerance and behavior of the EPN Heterorhabditis megidis strain UK211. The Us that emerge early display good initial host-finding ability and increased temperature tolerance but disperse poorly and have poor tolerance to desiccation. Conversely, the IJs that emerge later display poor initial host-finding ability and poor temperature tolerance but they disperse well and possess increased desiccation tolerance. These phenotypic differences are likely to facilitate early-emerging Us in locating and infecting hosts in the vicinity of the cadaver, whereas IJs that emerge late are adapted to disperse away from their natal cadaver. We hypothesize that adaptive phenotypic plasticity rather than allelic variability may provide the genetic basis for the different physiological and behavioral phenotypes of the early- and late-emerging IJs

    The effect of day of emergence from the insect cadaver on the behaviour and environmental tolerances of infective juveniles of the entomopathogenic nematode Heterorhabditis Megidis (Strain UK211)

    Get PDF
    Infective juveniles (Us) of entomopathogenic nematodes (EPNs) are obligate parasites of insect larvae. Inside the host they develop into sexually mature adult stages and complete their life cycle. Two or 3 adult nematode generations can occur in the insect host. The increase in nematode population density in the insect cadaver, together with limiting nutrient conditions, result in the formation of IJs. These IJs emerge into the soil to search for a new host. It typically takes 7-8 days for all Us to emerge from a parasitized insect. We have investigated the effect of the day of emergence of Us from insect cadavers on the environmental tolerance and behavior of the EPN Heterorhabditis megidis strain UK211. The Us that emerge early display good initial host-finding ability and increased temperature tolerance but disperse poorly and have poor tolerance to desiccation. Conversely, the IJs that emerge later display poor initial host-finding ability and poor temperature tolerance but they disperse well and possess increased desiccation tolerance. These phenotypic differences are likely to facilitate early-emerging Us in locating and infecting hosts in the vicinity of the cadaver, whereas IJs that emerge late are adapted to disperse away from their natal cadaver. We hypothesize that adaptive phenotypic plasticity rather than allelic variability may provide the genetic basis for the different physiological and behavioral phenotypes of the early- and late-emerging IJs

    The effect of day of emergence from the insect cadaver on the behaviour and environmental tolerances of infective juveniles of the entomopathogenic nematode Heterorhabditis Megidis (Strain UK211)

    No full text
    Infective juveniles (Us) of entomopathogenic nematodes (EPNs) are obligate parasites of insect larvae. Inside the host they develop into sexually mature adult stages and complete their life cycle. Two or 3 adult nematode generations can occur in the insect host. The increase in nematode population density in the insect cadaver, together with limiting nutrient conditions, result in the formation of IJs. These IJs emerge into the soil to search for a new host. It typically takes 7-8 days for all Us to emerge from a parasitized insect. We have investigated the effect of the day of emergence of Us from insect cadavers on the environmental tolerance and behavior of the EPN Heterorhabditis megidis strain UK211. The Us that emerge early display good initial host-finding ability and increased temperature tolerance but disperse poorly and have poor tolerance to desiccation. Conversely, the IJs that emerge later display poor initial host-finding ability and poor temperature tolerance but they disperse well and possess increased desiccation tolerance. These phenotypic differences are likely to facilitate early-emerging Us in locating and infecting hosts in the vicinity of the cadaver, whereas IJs that emerge late are adapted to disperse away from their natal cadaver. We hypothesize that adaptive phenotypic plasticity rather than allelic variability may provide the genetic basis for the different physiological and behavioral phenotypes of the early- and late-emerging IJs

    The effect of day of emergence from the insect cadaver on the behaviour and environmental tolerances of infective juveniles of the entomopathogenic nematode Heterorhabditis Megidis (Strain UK211)

    No full text
    Infective juveniles (Us) of entomopathogenic nematodes (EPNs) are obligate parasites of insect larvae. Inside the host they develop into sexually mature adult stages and complete their life cycle. Two or 3 adult nematode generations can occur in the insect host. The increase in nematode population density in the insect cadaver, together with limiting nutrient conditions, result in the formation of IJs. These IJs emerge into the soil to search for a new host. It typically takes 7-8 days for all Us to emerge from a parasitized insect. We have investigated the effect of the day of emergence of Us from insect cadavers on the environmental tolerance and behavior of the EPN Heterorhabditis megidis strain UK211. The Us that emerge early display good initial host-finding ability and increased temperature tolerance but disperse poorly and have poor tolerance to desiccation. Conversely, the IJs that emerge later display poor initial host-finding ability and poor temperature tolerance but they disperse well and possess increased desiccation tolerance. These phenotypic differences are likely to facilitate early-emerging Us in locating and infecting hosts in the vicinity of the cadaver, whereas IJs that emerge late are adapted to disperse away from their natal cadaver. We hypothesize that adaptive phenotypic plasticity rather than allelic variability may provide the genetic basis for the different physiological and behavioral phenotypes of the early- and late-emerging IJs

    Data extraction instrument.

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    Head porters working in markets in sub-Saharan Africa (SSA) are one of the world’s most vulnerable and socioeconomically disadvantaged groups. They consist predominantly of uneducated women and girls seeking to escape poverty, early marriage, and other issues of domestic violence. Most female head porters are in their reproductive years and often lack access to sexual reproductive health services (SRHS) despite being at high risk for sexually transmitted infections (STIs), unplanned pregnancies, and gender-based violence. The low priority for women and girls’ SRH in many SSA countries highlights the need to explore the factors influencing the accessibility of services for failure to do so restrains human development. An initial search of the literature was conducted and revealed no current scoping or systematic reviews on the accessibility to SRHS for female head porters in SSA. We outline a scoping review protocol, using the Joanna Briggs Institute methodology, to determine the interventions that influence the accessibility of SRHS for female head porters in SSA. The protocol is registered with Open Science Framework (https://osf.io/hjfkd). Findings will not only be valuable for female head porters but for all vulnerable female groups in SSA who experience high SRH risks and social disparities.</div

    Search strategy in Ovid Medline.

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    Head porters working in markets in sub-Saharan Africa (SSA) are one of the world’s most vulnerable and socioeconomically disadvantaged groups. They consist predominantly of uneducated women and girls seeking to escape poverty, early marriage, and other issues of domestic violence. Most female head porters are in their reproductive years and often lack access to sexual reproductive health services (SRHS) despite being at high risk for sexually transmitted infections (STIs), unplanned pregnancies, and gender-based violence. The low priority for women and girls’ SRH in many SSA countries highlights the need to explore the factors influencing the accessibility of services for failure to do so restrains human development. An initial search of the literature was conducted and revealed no current scoping or systematic reviews on the accessibility to SRHS for female head porters in SSA. We outline a scoping review protocol, using the Joanna Briggs Institute methodology, to determine the interventions that influence the accessibility of SRHS for female head porters in SSA. The protocol is registered with Open Science Framework (https://osf.io/hjfkd). Findings will not only be valuable for female head porters but for all vulnerable female groups in SSA who experience high SRH risks and social disparities.</div

    Search strategy of preliminary grey literature.

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    Head porters working in markets in sub-Saharan Africa (SSA) are one of the world’s most vulnerable and socioeconomically disadvantaged groups. They consist predominantly of uneducated women and girls seeking to escape poverty, early marriage, and other issues of domestic violence. Most female head porters are in their reproductive years and often lack access to sexual reproductive health services (SRHS) despite being at high risk for sexually transmitted infections (STIs), unplanned pregnancies, and gender-based violence. The low priority for women and girls’ SRH in many SSA countries highlights the need to explore the factors influencing the accessibility of services for failure to do so restrains human development. An initial search of the literature was conducted and revealed no current scoping or systematic reviews on the accessibility to SRHS for female head porters in SSA. We outline a scoping review protocol, using the Joanna Briggs Institute methodology, to determine the interventions that influence the accessibility of SRHS for female head porters in SSA. The protocol is registered with Open Science Framework (https://osf.io/hjfkd). Findings will not only be valuable for female head porters but for all vulnerable female groups in SSA who experience high SRH risks and social disparities.</div
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