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Infestation
About: Infestation is a research topic. Over the lifetime, 8308 publications have been published within this topic receiving 82305 citations.
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TL;DR: Evidence for local adaptation to individual plants was not found: nymphs transplants to the trees from which their parents were collected neither established more readily nor showed lower mortality than those transplanted to other trees with similar levels of infestation.
Abstract: .
1
In Kenya, the aphid Cinara cupressi (Buckton) has an aggregated distribution across individuals of its host plant, the Mexican cypress, Cupressus lusitanica (Mill).
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There are significant differences in host plant quality: C.cupressi nymphs transplanted onto cypress trees with low aphid infestations are significantly less likely to establish than aphids transplanted onto trees with high aphid infestations.
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Given that some transplanted nymphs establish, the previous level of infestation does not influence aphid survival.
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Evidence for local adaptation to individual plants was not found: nymphs transplanted to the trees from which their parents were collected neither established more readily nor showed lower mortality than those transplanted to other trees with similar levels of infestation. Therefore the variation in host plant quality has not led to the development of local adaptation to particular host plants.
27 citations
01 Jan 2005
27 citations
TL;DR: A priori models that represented explicit hypotheses and contrasted their ability to predict infestation patterns emphasized the need to simultaneously assess the relative importance of multiple ecological variables between parasite species when attempting to describe general trends and constraints of host–parasite associations.
Abstract: A variety of demographic, seasonal, and site-specific variables may influence parasitism, but the relative importance of these variables is generally unclear. We measured the relative ability of host characteristics, season, and site to explain louse (Trichodectes octomaculatus) and flea (Orchopeas howardi) infestation across 10 populations of raccoons (Procyon lotor). Lice are highly dependent on specific hosts and are predicted to display a relatively strong relationship with factors intrinsic to the host, when compared to fleas, which can infest multiple species and survive off-host for weeks without feeding. We developed a priori models that represented explicit hypotheses and contrasted their ability to predict infestation patterns. While the abundance of lice was seasonal, models that included solely host age and sex best predicted prevalence and abundance, in part because males were infested with 3 times the number of lice than were females. Conversely, flea prevalence and abundance, which...
27 citations
TL;DR: The ovipositional response, laraval orientation, larval settling, feeding, food assimilation, growth and development of maize stemborer ChUo partellus (Swinhoe) on a susceptible maize genotype was compared to five wild plant species of the family Poaceae (Gramineae) in the laboratory and greenhouse.
Abstract: The ovipositional response, larval orientation, larval settling, feeding, food assimilation, growth and development of maize stemborer ChUo partellus (Swinhoe) (Lepidoptera: Pyralidae) on a susceptible maize (Zea mays L.) genotype (Inbred A) was compared to five wild plant species of the family Poaceae (Gramineae) in the laboratory and greenhouse. The intensity of oviposition differed among the test plants. Pennisetum purpureum Schumach was the most preferred test plant for oviposition when offered in a two-choice situation with maize. Likewise, P. purpureum and Sorghum versicolor Anderss were the most preferred test plant for oviposition when offered in multiple-choice tests. In no-choice tests C. partellus responses to the test plants were not significantly different. The number of first instar larvae that settled on leaf cuts of test plants in Petri dishes was significantly higher on maize and S. versicolor than on the other test plants at 24 h after infestation in a multiple-choice test. No significant differences were observed in larval settling among wild grasses at 4 h and 24 h after infestation in a no-choice test. In a two- choice test there was no significant difference in the number of neonate larvae that settled on maize and S. versicolor at 1 h and 24 h after infestation. Feeding by fourth-instar larvae was significantly higher on maize than on Echinochloa pyramidalis (Lam.) and Hyparrhenia rufa (Nees) Stapf. Larvae fed on maize assimilated significantly more food than those fed on E. pyramidalis, Panicum maximum Jacq. or H. rufa. Larval growth and development was significantly faster on maize and S. versicolor in comparison to other test plants.
27 citations
TL;DR: Investigation of soil microbial communities in an apple orchard and its adjacent boundary bush with or without infestation by violet root rot suggested that the seasonal and the land-use factors affected soil microbial community both quantitatively and qualitatively, whereas the impact of the violetRoot rot was mainly qualitative and more pronounced in the adjacent bush than in the orchard.
Abstract: Soil microbial communities in an apple orchard and its adjacent boundary bush with or without infestation by violet root rot were investigated for 2 years. Effects of season (spring, summer, and fall), land-use (apple orchard and boundary bush), and violet root rot (infested and healthy) on soil microbial populations, microbial activity, and microbial community structures were determined using physiological, cytochemical, and molecular (PCR-DGGE) approaches. Seasonal fluctuations were significant ( P H ′) and evenness ( J ′) of community-level physiological profile (CLPP) in both years. However, seasonal differences of soil microbial guilds that utilize carbon substrate groups observed in the first year were not reproduced in the second year. The land-use factor differentiated the apple orchard from the boundary bush where viable bacterial population, bacterial FAME and FDA hydrolysis were significantly greater in both years. Infestation status of violet root rot, on the other hand, significantly increased bacterial FAME and FDA hydrolysis in both years. In addition, neither the land-use nor the disease infestation factor significantly influenced the utilization patterns of individual substrate guilds for the 2 years. In both years, saturated fatty acids were significantly more abundant in the orchard than in the bush soil, and monosaturated fatty acids vice versa. Principal component analyses for CLPP, FAME, and denaturing gradient gel electrophoresis (DGGE) consistently exhibited that, although the violet root rot influenced the soil microbial community structures both in the apple orchard and the boundary bush, overall magnitude of the difference in communities between the violet root rot infested and non-infested sites in the bush were greater than in the orchard, irrespective of the season. These results suggested that the seasonal and the land-use factors affected soil microbial community both quantitatively and qualitatively, whereas the impact of the violet root rot on the soil microbial community was mainly qualitative and more pronounced in the adjacent bush than in the orchard.
27 citations