Infestation

About: Infestation is a research topic. Over the lifetime, 8308 publications have been published within this topic receiving 82305 citations.

Controle de larvas de Boophilus microplus por Metarhizium anisopliae em pastagens infestadas artificialmente

Abstract: The objective of this work was to evaluate the efficiency of Metarhizium anisopliae fungus against Boophilus microplus population in Brachiaria brizantha and Tifton 85 (Cynodon) pastures, artificially infested with tick engorged females. Thirty plots of 1 m2 each were randomly distributed in fifteen treated and fifteen control groups per type of grass, establishing five repetitions for each treatment. Pastures were infested with engorged tick females standardized by number and weight. Metarhizium anisopliae suspension with 1.8x108 conidia mL-1 concentration was sprayed on the plot in three different assays, prior infested with tick females, immediately after tick inoculation and at first larvae emergency. The fungus action was evaluated at 35th, 38th, 41st, 48th, 55th and 61st day post infestation by counting recovered larvae. A significative reduction of larvae counts occurred in fungus treated groups during 35th to 48th day post infestation, ranging between 87% and 94% of efficacy on tick larvae control. The mean values for larvae counting in Tifton 85 pasture were lower than in B. brizantha plot in all analysis, suggesting the pasture effect on fungus action. Treatment strategy influenced on M. anisopliae activity, which demonstrated better results at 41st and 55th day post infestation in B. brizantha, submitted to conidia challenge after larvae emergency.

The prevalence of ectoparasites in Ethiopian immigrants.

Abstract: Newly arrived Ethiopian immigrants in Israel were screened for ectoparasitic insects and mites. Of 304 individuals examined 65.1% were infested with the head louse (Pediculus humanus capitis). The infestation rate among children varied between 65 and 100%. Children aged 6-11 years were the most infested group and no differences between girls and boys were found. The infestation rate in children was significantly higher than that found in adults. Approximately 39% of those examined were infested with the body louse (Pediculus humanus humanus). The rate of infestation with this parasite was higher in adults than in children and higher in females than males. Ten percent of the immigrants examined were infested with the scabies mite (Sarcoptes scabiei) and 4.3% with the human flea (Pulex irritans).

Infestation of the Pearl Oyster Pinctada margaritifera (Linné) by a new species of Polydora in Kuwait, Arabian Gulf

Abstract: 1. The present study deals with infestation of the pearl oyster, Pinctada margaritifera (Linne), by a new polychaetous annelid, Polydora vulgaris sp. nov. A part of the work is devoted to a description of seasonal changes in some hydrological features of the Kuwaitian waters. Structural details of the pest are also given. 2. The pearl oysters were collected during the summer of 1970. Data on the hydrological factors were obtained, usually at bi-weekly intervals, from 15 June 1970 to 20 August 1971. 3. In all, 20,733 pearl oysters were opened and examined, and of this number 4.68% were infested with the spionid. Percentage of infestation was much higher (14.77%) among the older oysters than the younger ones (0.28%). 4. A total of 911 oysters (4.39%) contained pearls and of these 19.43% were infested with the worm. Again, infestation was 41.2% in old pearl carriers and 5.2% in the young ones. 5. There was an inverse correlation between the percentage of infestation and weight (but not number) of the pearls yielded per oyster. No other ill effect of infestation was perceptible.

Costs and benefits of hydroxamic acids-related resistance in winter wheat against the bird cherry-oat aphid, Rhopalosiphum padi L.

Abstract: Summary. Estimations of infestation by the bird cherry-oat aphid (Rhopalosiphum padi) as well as measurements of grain yield in 26 Hungarian winter wheat cultivars under field conditions were correlated with the concentration of hydroxamic acids (Hx) in seedlings of those cultivars. The significant inverse relationship between infestation ratings and Hx levels in wheat showed that Hx, despite their decreased accumulation at later plant phenological stages, may be able to confer resistance against aphid infestation in the field. Since no significant relationship was found between grain yield and Hx levels in plants it is suggested that Hx accumulation does not impose a cost to the plant in terms of yield. These findings support earlier claims stressing the potential of Hx as breeding targets for aphid resistance in wheat.

Observations on an Infestation by Green Peach Aphids (Homoptera: Aphididae) on Greenhouse Tomatoes in Italy

Abstract: The ecology and biology of green peach aphids, Myzus persicae (Sulzer), were studied on greenhouse tomatoes with the goals of learning more about the biology of the species in these conditions and of measuring parameters to implement a computer simulation that could be used in programs for resistance management. Control groups and groups of tomatoes (‘Ausonio’and‘Acor’) treated with deltamethrin were observed throughout the growing season, and selected plants were observed in detail. At weekly intervals, the following measurements were recorded: height of the plant, number of leaves and flower clusters, health condition, phenological phase of the plant, presenceabsence of M. persicae (and if present, the numbers for each life stage on each leaf or flower bud), and the presence-absence of other parasitoids and predators. Although the trial demonstrated the efficacy of chemical treatments in reducing the number of aphids, the infestation did not seem to have consistent effects on fruit production.