Plants with leaves having numerous trichomes or domatia frequently harbor greater numbers of phyt... more Plants with leaves having numerous trichomes or domatia frequently harbor greater numbers of phytoseiid mites than do plant with leaves that lack these structures. We tested the hypothesis that this pattern occurs, in part, with Typhlodromus pyri because trichomes increase the capture of pollen or fungal spores that serve as alternative food. Using a common garden orchard, we found that apple varieties with trichome-rich leaves had 2-3 times more pollen and fungal spores compared to varieties with trichome-sparse leaves. We also studied the effects of leaf trichome density and pollen augmentation on T. pyri abundance to test the hypothesis that leaf trichomes mediate pollen and fungal spore capture and retention and thereby influence phytoseiid numbers. Cattail pollen (Typha sp.) was applied weekly to mature 'McIntosh' and 'Red Delicious' trees grown in an orchard and, in a separate experiment, to potted trees of the same varieties. 'McIntosh' trees have leav...
In this study we asked whether, in the context of a trap crop system, differential predation risk... more In this study we asked whether, in the context of a trap crop system, differential predation risks among plants influence host choice patterns of adult whiteflies, Bemisia argentifolii. We investigated whether adult whiteflies avoid natural enemies inhabiting poinsettia (a cash crop) and whether this behavior can be used to increase the movement of whiteflies to cucumber (a trap crop). The
Received June 19, 1991 / Accepted in revised form December 30, 1991 ... Summary. Responses of the... more Received June 19, 1991 / Accepted in revised form December 30, 1991 ... Summary. Responses of the predaceous mites Phytoseiul-us persimilis, Typhlodromus (= Metaseiulus ) occidentalis, and Amblyseius andersoni to spatial variation in egg den-sity of the ...
A 3-year demonstration study was conducted in four western New York apple orchards to evaluate cu... more A 3-year demonstration study was conducted in four western New York apple orchards to evaluate current approaches of sustainable pest management in representative commercial orchards. Pests that could be tolerated were regulated by natural antagonists, including predatory mites that were introduced to supplement endemic populations, while those with lower tolerance levels were managed with a schedule of selective pesticides, e.g.,
The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (G... more The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation,
... P, O'Dowd DJ (1994) Plants, mites and mutualism: leaf domatia and the abundance and repr... more ... P, O'Dowd DJ (1994) Plants, mites and mutualism: leaf domatia and the abundance and reproduction of mites on Vi-burnum tinus (Caprifoliaceae). ... Entomol 18:698– 704 Kleijn PW, Krips OE, Willems PEL, Dicke M (1997) The influ-ence of leaf hairs of Gerber jamesonii on the ...
... 1995), was called tripartite sequential classification (TSC), because there are three decisio... more ... 1995), was called tripartite sequential classification (TSC), because there are three decision alternatives at ... AFC) is such a variation, allowing the skipping of multiple sample occasions, if ... First, we describe a four-step procedure for developing monitoring protocols and assessing ...
ABSTRACT Trap cropping, though promising, has had little evaluation in greenhouses. This study ev... more ABSTRACT Trap cropping, though promising, has had little evaluation in greenhouses. This study evaluated eggplant, Solanum melongena L. (Solanaceae), as a trap crop for two whitefly species, Trialeurodes vaporariorum (Westwood) and Bemisia argentifolii Bellows & Perring (both Hemiptera: Aleyrodidae), on greenhouse poinsettia, Euphorbia pulcherrima Willd. ex Koltz (Euphorbiaceae). Because the two whitefly species co-occur in greenhouses, a common trap crop for both whiteflies is desirable. When adults were provided a choice between eggplant and poinsettia in a cage, 60% of B. argentifolii and 98% of T. vaporariorum were observed on eggplant after 3 days. However, when adults were given eggplant after first settling on poinsettia, only 38% of B. argentifolii were later found on eggplant, whereas 95% of T. vaporariorum moved to eggplant. In a greenhouse experiment, eggplant did not affect either the spatial distribution or density of adult B. argentifolii on poinsettias. In contrast, eggplant changed the spatial distribution of T. vaporariorum within 3 days by attracting and retaining the adults. However, the attractiveness of eggplant did not result in a reduced number of T. vaporariorum on poinsettias compared with poinsettias in monoculture. Adult T. vaporariorum mortality was high on poinsettias and this likely caused adult density on poinsettias in monoculture to decrease as fast as that under trap cropping. A simulation model was developed to examine how adult whitefly mortality on poinsettia influences trap cropping effectiveness. When whitefly mortality was high, simulated densities were similar to the experimental data. This reveals an unexpected factor, pest mortality on the main crop, that can influence the relative effectiveness of trap cropping. Our results indicate that eggplant will not work unilaterally as a trap crop for B. argentifolii. For T. vaporariorum, attraction to eggplant might be useful as a trap crop system when whitefly mortality on the main crop is not high.
Plants with leaves having numerous trichomes or domatia frequently harbor greater numbers of phyt... more Plants with leaves having numerous trichomes or domatia frequently harbor greater numbers of phytoseiid mites than do plant with leaves that lack these structures. We tested the hypothesis that this pattern occurs, in part, with Typhlodromus pyri because trichomes increase the capture of pollen or fungal spores that serve as alternative food. Using a common garden orchard, we found that apple varieties with trichome-rich leaves had 2-3 times more pollen and fungal spores compared to varieties with trichome-sparse leaves. We also studied the effects of leaf trichome density and pollen augmentation on T. pyri abundance to test the hypothesis that leaf trichomes mediate pollen and fungal spore capture and retention and thereby influence phytoseiid numbers. Cattail pollen (Typha sp.) was applied weekly to mature 'McIntosh' and 'Red Delicious' trees grown in an orchard and, in a separate experiment, to potted trees of the same varieties. 'McIntosh' trees have leav...
In this study we asked whether, in the context of a trap crop system, differential predation risk... more In this study we asked whether, in the context of a trap crop system, differential predation risks among plants influence host choice patterns of adult whiteflies, Bemisia argentifolii. We investigated whether adult whiteflies avoid natural enemies inhabiting poinsettia (a cash crop) and whether this behavior can be used to increase the movement of whiteflies to cucumber (a trap crop). The
Received June 19, 1991 / Accepted in revised form December 30, 1991 ... Summary. Responses of the... more Received June 19, 1991 / Accepted in revised form December 30, 1991 ... Summary. Responses of the predaceous mites Phytoseiul-us persimilis, Typhlodromus (= Metaseiulus ) occidentalis, and Amblyseius andersoni to spatial variation in egg den-sity of the ...
A 3-year demonstration study was conducted in four western New York apple orchards to evaluate cu... more A 3-year demonstration study was conducted in four western New York apple orchards to evaluate current approaches of sustainable pest management in representative commercial orchards. Pests that could be tolerated were regulated by natural antagonists, including predatory mites that were introduced to supplement endemic populations, while those with lower tolerance levels were managed with a schedule of selective pesticides, e.g.,
The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (G... more The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation,
... P, O'Dowd DJ (1994) Plants, mites and mutualism: leaf domatia and the abundance and repr... more ... P, O'Dowd DJ (1994) Plants, mites and mutualism: leaf domatia and the abundance and reproduction of mites on Vi-burnum tinus (Caprifoliaceae). ... Entomol 18:698– 704 Kleijn PW, Krips OE, Willems PEL, Dicke M (1997) The influ-ence of leaf hairs of Gerber jamesonii on the ...
... 1995), was called tripartite sequential classification (TSC), because there are three decisio... more ... 1995), was called tripartite sequential classification (TSC), because there are three decision alternatives at ... AFC) is such a variation, allowing the skipping of multiple sample occasions, if ... First, we describe a four-step procedure for developing monitoring protocols and assessing ...
ABSTRACT Trap cropping, though promising, has had little evaluation in greenhouses. This study ev... more ABSTRACT Trap cropping, though promising, has had little evaluation in greenhouses. This study evaluated eggplant, Solanum melongena L. (Solanaceae), as a trap crop for two whitefly species, Trialeurodes vaporariorum (Westwood) and Bemisia argentifolii Bellows & Perring (both Hemiptera: Aleyrodidae), on greenhouse poinsettia, Euphorbia pulcherrima Willd. ex Koltz (Euphorbiaceae). Because the two whitefly species co-occur in greenhouses, a common trap crop for both whiteflies is desirable. When adults were provided a choice between eggplant and poinsettia in a cage, 60% of B. argentifolii and 98% of T. vaporariorum were observed on eggplant after 3 days. However, when adults were given eggplant after first settling on poinsettia, only 38% of B. argentifolii were later found on eggplant, whereas 95% of T. vaporariorum moved to eggplant. In a greenhouse experiment, eggplant did not affect either the spatial distribution or density of adult B. argentifolii on poinsettias. In contrast, eggplant changed the spatial distribution of T. vaporariorum within 3 days by attracting and retaining the adults. However, the attractiveness of eggplant did not result in a reduced number of T. vaporariorum on poinsettias compared with poinsettias in monoculture. Adult T. vaporariorum mortality was high on poinsettias and this likely caused adult density on poinsettias in monoculture to decrease as fast as that under trap cropping. A simulation model was developed to examine how adult whitefly mortality on poinsettia influences trap cropping effectiveness. When whitefly mortality was high, simulated densities were similar to the experimental data. This reveals an unexpected factor, pest mortality on the main crop, that can influence the relative effectiveness of trap cropping. Our results indicate that eggplant will not work unilaterally as a trap crop for B. argentifolii. For T. vaporariorum, attraction to eggplant might be useful as a trap crop system when whitefly mortality on the main crop is not high.
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