Showing papers on "Infestation published in 1994"
Book•
31 Aug 1994
TL;DR: The mites and ticks - acarina, the insects - insecta, and other harmful arthropods: methods for identification.
Abstract: Acknowledgements. Introduction. Glossary. How to use this book. The mites and ticks - acarina. The insects - insecta. Other harmful arthropods. Delusions of infestation. Books. Methods for identification. Index.
80 citations
Journal Article•
69 citations
TL;DR: An intensive population census of Bactrocera latifrons (Hendel) identified 15 species of suitable host plants (11 solanaceous, 4 cucurbitaceous), 6 of them new host records, and B. latifron populations decreased as the elevation increased, and there was no discernible pattern of population fluctuation over time.
Abstract: An intensive population census of Bactrocera latifrons (Hendel) identified 15 species of suitable host plants (11 solanaceous, 4 cucurbitaceous), 6 of them new host records. Lycopersicon pimpinellifolium (Jusl.) Mill., Solanum nigrescens Mart. & Galeotti, Solatium sodomeum L., and Solanum torvum Sw. were the most heavily infested host plants in feral habitats. Under backyard and commercial cultivations, Capsicum annuum L., Lycopersicon lycopersicum (L.) Karst. ex Farw., and Solanum melongena L. were the most heavily infested (larval density and percentage infestation). B. latifrons appears to outcompete melon fly, oriental fruit fly, and Mediterranean fruit fly in C. annuum, Capsicum frutescens L., L. pimpinellifolium, Physalis peruviana L., S. melongena, S. nigrescens, S. nigrum, S. sodomeum , and S. torvum . Extremely low (<1%) larval parasitization by Diachasmimorpha longicaudata (Ashmead) was observed. Larval parasitization by Tetrastichus sp. was also observed. More than 250 cm average annual cumulative rainfall probably excluded B. latifrons populations from areas where suitable host plants were abundant. Over the study period, the relative abundance of B. latifrons populations decreased as the elevation increased. B. latifrons population density levels were consistently low, and there was no discernible pattern of population fluctuation over time (months of collection). Comprehensive lists of all recorded host plants (world review) and natural enemies of B. latifrons are presented. The ecological attributes of B. latifrons populations and their adaptive significance in colonizing and establishing in new geographic areas are discussed.
67 citations
TL;DR: In this paper, the authors evaluated four species of Cruciferae [canola species Brassica rapa L., Brassica napus L., and Brassica juncea (L.) and Sinapis alba L. under field conditions in central Alberta, Canada.
Abstract: Four species of Cruciferae [canola species Brassica rapa L. and Brassica napus L., and mustard species Brassica juncea (L.) and Sinapis alba L.], and various cultivars of each species, were evaluated for susceptibilities to infestation by Delia spp. (Diptera: Anthomyiidae) under field conditions in central Alberta, Canada. Susceptibility was measured throughout the season by recording numbers of eggs of Delia spp. laid on or near individual plants, and at the end of the season by a semi-quantitative determination of injury inflicted by larvae on taproots. Differences in susceptibility occurred among and within canola and mustard species. Plants of B. rapa were most susceptible to Delia spp.; both mean eggs per plant and mean damage ratings per plant on B. rapa significantly exceeded those of all other species studied. Intermediate susceptibility was observed for plants of B. napus and B. juncea; plants of S. alba were least susceptible. In general, differences in susceptibility were greater among species than among cultivars within species. Root damage generally correlated with oviposition among and within species, suggesting that the mechanism of resistance by cruciferous species to infestation by Delia spp. is antixenosis or nonpreference. Results of this study indicate that canola growers in regions infested annually by high population densities of Delia spp. should seed B. napus or B. juncea rather than B. rapa. However, if a short growing season necessitates seeding B. rapa, then growers should select the more resistant cultivars of this species.
64 citations
TL;DR: A resistant barley was used to compare physiological responses of a susceptible barley to the recently introduced pest, Russian wheat aphid, Diuraphis noxia (Mordvilko), and well-watered PI 366450 showed greater stomatal closure in response to aphid infestation than ‘Morex’.
Abstract: A resistant barley ( Hordeum vulgare L., PI 366450) was used to compare physiological responses of a susceptible barley (‘Morex’) to the recently introduced pest, Russian wheat aphid, Diuraphis noxia (Mordvilko). As measured by chlorosis, leaf rolling, and streaking, damage by Russian wheat aphid was greater in ‘Morex’ than in PI 366450. The inhibition of growth, as measured by plant height, shoot dry weight, and number of leaves, also was greater in ‘Morex’ than in PI 366450. Relative water contents of leaves or stems showed no differences between ‘Morex’ and PI 366450 as a result of infestation. Well-watered PI 366450 showed greater stomatal closure in response to aphid infestation than ‘Morex’. However, the stomatal resistance responses of water-deprived PI 366450 and ‘Morex’ to Russian wheat aphids could not be distinguished. The two-dimensional SDS-PAGE protein profiles of uninfested ‘Morex’ and PI 366450 leaves were virtually identical. Upon infestation, a complex of proteins (≈23 kD) was altered in the PI 366450 profile and had decreased levels in ‘Morex’. Chlorophyll measurements indicated a greater relative loss of chlorophyll during infestation in ‘Morex’ than in PI 366450 when deprived of water; no differences could be distinguished when well watered. Measurements of the effectiveness of photosystem II to transfer electrons also showed no differences between well-watered resistant and susceptible barleys as a result of aphid infestation. However, the ability of the quinone pool in ‘Morex’ to recover after illumination was reduced greatly relative to that of PI 366450.
53 citations
TL;DR: The results indicate that control of serious Amyema miquelii infestation of individual trees will be worthwhile in terms of immediate host survival and higher growth rate, and prudent long-term management may well allow for the loss of small numbers of farm trees to mistletoes when planning tree recruitment and utilisation.
53 citations
Journal Article•
TL;DR: Factors associated with the onset of pediculosis included overcrowding, long hair, family size, age, living in a sordid environment, and personal hygiene, according to a survey of primary school children in Ilorin, Nigeria.
Abstract: A survey of 6882 primary school children living in Ilorin, Nigeria revealed that 3.7% of the children were infested with Pediculus humanus capitis. Infestation rate among the children in the Islamic community was 4.1%, whereas in the Christian area, the infestation rate was 3%. Girls had a higher infestation rate (5.6%) than boys (2.1%). The highest infestation rate (28.4%) was observed among girls of low socioeconomic class, followed by their male counterparts (11.2%). Factors associated with the onset of pediculosis included overcrowding, long hair, family size, age, living in a sordid environment, and personal hygiene. Strategies for the effective control of pediculosis are discussed.
47 citations
TL;DR: A living mulch is an intercropping system which combines an annual crop with a cover crop in order to achieve better weed and insect control, enhance soil fertility and reduce soil erosion and compaction.
Abstract: A living mulch is an intercropping system which combines an annual crop with a cover crop in order to achieve better weed and insect control, enhance soil fertility and reduce soil erosion and compaction. In this study broccoli (Brassica oleracea var. botrytis L.) was grown under clean cultivation (no cover crop) and in living mulches using three leguminous cover crops: white clover (Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixture of birdsfoot trefoil (Lotus corniculatus L.) and red clover (Trifolium praetense L.). Aphid infestation of harvested broccoli heads, leaf area, leaf water content, leaf nitrate-nitrogen and yields were assessed. Fertiliser was applied at commercial rates as synthetic fertiliser or compost crossed with cover crop regime. In plots fertilised with compost aphid infestation on harvested broccoli heads was consistently less in living mulches than under clean cultivation. Nitrogen availability was lower in all compost subplots, as indicated by ...
41 citations
TL;DR: Different infestation levels with the greenbug were correlated with physiological parameters and several metabolite concentrations in young barley plants, suggesting several metabolic changes that occur in barley infested by a large number of aphids may be due in part to the lower leaf water potential caused by the insect.
38 citations
TL;DR: The relationship between an individual dodder and an individual host plant is neutral, due to the array of direct and indirect, positive and negative effects appearing between Cuscuta and H. spinosa during the sucessives phases of the reproductive cycle of the host plant.
Abstract: In this paper, I analyse the interaction between a parasitic angiosperm (Cuscuta epithymum, Cuscutaceae) and its host plant (Hormathophylla spinosa, Cruciferae), taking into account the other species which directly affect the fitness of the host plant. I studied the spatial pattern of Cuscuta infestation in H. spinosa in the Sierra Nevada, Spain, for 6 years (1988-1993). In addition, I assessed the composition and abundance of the pollinator assemblage of Cuscuta during 1991. I determined the effect of dodder on H. spinosa reproductive success by comparing the fruit and seed production of both parasitized and non-parasitized host plants, and determining the mortality factors affecting reproductive potential. Cuscuta epithymum was found to parasitize the labelled host plants only in three of the six years of study, and only in two of the three host plant populations. The maximum percentage of infestation ocurred in 1990, in which 20% of the labelled host plants were parasitized by dodders in one population and 15% in the other population. No labelled host plant had more than 35% of its canopy surface covered by dodders. Parasitized plants were visited by fewer pollinators than were non-parasitized plants. In addition, the diversity of the pollinator assemblage also differed between these two groups of plants. The dodder did not significatively affect the fruit or seed production of its host plant, either during the study years or the years following the strong infestation. The dodder causes little harm mainly because it is scarce. However, even the relationship between an individual dodder and an individual host plant is neutral, due to the array of direct and indirect, positive and negative effects appearing between Cuscuta and H. spinosa during the sucessives phases of the reproductive cycle of the host plant.
33 citations
TL;DR: Results suggest that common antigens are present in different tissues of B. microplus and their humoral immune response to salivary gland, gut, embryo and larval extracts during infestation was determined.
TL;DR: The infestation of seed by Fusarium oxysporum f.sp.
Abstract: The infestation of seed by Fusarium oxysporum f.sp. radicis-lycopersici occurred at rates of 0-1 to 0-01 % in fruit on stem-infected plants. Direct infection of fruit in the flower or young developing fruit stage resulted in a grayish-brown lesion on the stylar end of the fruit or mummification. F. oxysporum f.sp. radicis-lycopersici was isolated from all seeds in such fruit. Picked fruit inoculated on the stem scar also became infected but 96 h after inoculation of the fruit, the seed was not infested or infected. The contact of clean seed with hands that had previously handled F. oxysporum f.sp. radicis-lycoperisid-infesied sawdust resulted in a high level of seed infestation. The fungus survived on seed sent across Canada and stored for up to 12 weeks. Treatment with NaOCl or 0·1 N HCl did not completely disinfest infested seed.
TL;DR: In this paper, the authors conducted field trials at St-Augustin, near Quebec City, Canada, to detennine the critical periods of quackgrass control in potato submitted to three levels of infestation.
Abstract: Field trials were carried out in 1989 and 1990 at St-Augustin, near Quebec City, Canada, to detennine the critical periods of quackgrass control in potato submitted to three levels of infestation. Potato yield losses due to quack- grass interference increased with quack'grass infestation and length of duration of interference. Quackgrass interference influenced marketable tuber yields more than total tuber yields. Duration of the critical period varied depending on the level of quackgrass infestation and year. Based on an arbitrary 5% level of marketable yield loss, the critical pe- riod started at ca. 15 days after emergence (DAE) of potato at low level of infestation, and at ca. 3 DAE at medium level of infestation. At high level of infestation, the critical period began priorto the emergence of potato. The end of the critical period of quackgrass removal was extremely variable across quackgrass infestation level and year and ranged from 23 to 68 DAE of potato at a 5 % yield loss level. It appears that onset of interference varied less than the end of it, indicating that early quackgrass control is necessary to prevent yield loss. Nomenclature: Quackgrass, (Elytrigia repens (L.) Nevski #3 AGRRE); potato, (Solanum tuberosum L.) 'Superior.' Additional index words. Weed interference, weed density, crop
TL;DR: It is indicated that storage pests can infest the crop at any time from field maturation to the storage period, however, particularly in the case of P. truncatus, the earlier they arrive the greater the risk of loss not only from the progeny of the original colonizers but also because further adults appear to be attracted to existing infestations.
TL;DR: It was showed that cassava was in drought stress conditions during the dry season (foliar area decreased) and the combination of infestation and dry stress factors was clearly visible during the d r ~ season.
Abstract: A previous study on the population dynamics of the cassava mealybug, Phenacoccus manihoti (Matile-Ferrero), on cassava has shown that populations increase during the dry season. The aim of the present studies was to determine whether these important changes in the pest population observed throughout the seasons in the field in the Congo, could be correlated with seasonal variations in the level of secondary compounds in the phloem, implicated in cassava plant resistance to P. manihoti. Our results showed that cassava was in drought stress conditions during the dry season (foliar area decreased). The combination of infestation and dry stress factors was clearly visible during the dry season. In fact, the decrease in leaf water potential together with infestation by P. manihoti was clearly observed at the end of the rainy season and during the dry season. The levels of the secondary compounds, rutin (an unfavourable substance to P. manihoti) decreased in the less resistant genotype, and cyanide (a phagostimulant substance) increased in each genotype in the dry season. These results may partially explain the important population changes in P. manihoti during the seasons.
TL;DR: Temporal patterns of numbers of larvae collected from mice and through dragging in bottomland forest were significantly correlated and relative density of I. scapularis larvae and prevalence of nymphs on mice did not differ significantly amongBottomland forest, field-forest ecotone, and upland forest habitats.
Abstract: The effects of season and habitat on the infestation of the white-footed mouse (Peromyscus leucopus) by immature Ixodes scapularis were studied at Castle Rock State Park, northwestern Illinois, during June-October 1991. Relative density of larvae on mice was higher in mid-late summer (13.7 ticks per mouse) than during the rest of the study period, whereas prevalence of nymphal infestation was highest in early summer (33.3%). Relative density of I. scapularis larvae and prevalence of nymphs on mice did not differ significantly among bottomland forest, field-forest ecotone, and upland forest habitats. In bottomland forest, total number of ticks collected from mice (472 larvae and 13 nymphs) and P. leucopus population density (6.6 mice per 0.36 ha) were higher than in the other habitats. Temporal patterns of numbers of larvae collected from mice and through dragging in bottomland forest were significantly correlated.
TL;DR: Sweetpotato whitefly, Bemisia tabaci (Gennadius), has recently become a pest of peanut in the southern United States and whether selected cultivars grown commercially in this region resisted whitefly infestation and whether parasitism by aphelinid parasitoids differed among cultivars was determined.
Abstract: Sweetpotato whitefly, Bemisia tabaci (Gennadius), has recently become a pest of peanut in the southern United States. Limited observations in grower fields had identified differences in infestation among cultivars. We wished to determine whether selected cultivars grown commercially in this region resisted whitefly infestation and whether parasitism by aphelinid parasitoids differed among cultivars. Five cultivars were evaluated in summer 1992 and six in summer 1993. In 1992, ‘Florunner’ supported the greatest populations of red-eye nymphs and ‘Southern Runner’ supported the lowest populations. Encarsia nigricephala Dozier was the most common parasitoid (53.0% of all parasitoids reared), followed by Encarsia transvena (Timberlake) (25.6%), and Encarsia pergandiella Howard (18.3%). Parasitism was uniformly high and species composition on the five cultivars did not differ. In 1993, ‘Southern Runner’ supported the greatest populations of all immature whitefly stages except red-eye nymphs. ‘Marc I’ supported the lowest levels of whitefly infestation. E. nigricephala was extremely abundant in 1993 (85.3% of all parasitoids reared), followed by E. pergandiella (9.8%), and E. transvena (4.7%). Eretmocerus nr. californicus was found in low numbers in both years. Again, in 1993, parasitism was high on all cultivars (up to 100% by the end of September), and no differences were noted in the parasitoid composition among the six cultivars. Whitefly infestation was light in these noninsecticide-treated peanut plots, most likely because of natural control by native aphelinid parasitoids, and other beneficial insects.
TL;DR: The seasonal occurrence of ticks infesting cattle was monitored in a Bos taurus x Bos indicus commercial herd fed on a combination of native grasses and annual pastures in northwestern Argentina and the peak of Boophilus microplus was detected while cattle were on natural grasses in deforested habitats, peaks of other tick species were found when cattle wereon natural grasse in forested habitats.
TL;DR: There were substantial losses in thiamine, riboflavin and niacin contents of wheat, maize and sorghum grains at three infestation levels (25, 50 and 75%) caused by releasing two insect species viz., Trigoderma granarium and Rhizopertha dominica separately and mixed population.
Abstract: There were substantial losses in thiamine, riboflavin and niacin contents of wheat, maize and sorghum grains at three infestation levels (25, 50 and 75%) caused by releasing two insect species viz., Trogoderma granarium and Rhizopertha dominica separately and mixed population. Losses were to the extent of 65 to 69% (thiamine), 50 to 67% (riboflavin) and 10 to 32% (niacin) due to T. granarium and 23 to 29% (thiamine), 13 to 18% (riboflavin) and 4 to 14% (niacin) due to R. dominica at 75% level of infestation in three cereal grains. Storage of grains (1-4 months) in insect free conditions did not show appreciable changes in the vitamin contents.
01 Jan 1994
TL;DR: The association between levee vegetation and rice infestation level by the rice water weevil, Lissorhoptrus oryzophilus Kuschel, was evaluated in California’s Sacramento Valley.
Abstract: The association between levee vegetation and rice infestation level by the rice water weevil, Lissorhoptrus oryzophilus Kuschel, was evaluated in California’s Sacramento Valley. Fields with vegetated versus bare levees were compared for adult weevil infestation during the spring flight period. Lower infestations were associated with bare levees at 13 of 15 locations from 1990 to 1992. Weevil infestation remained below the recommended treatment level at 8 of 15 bare levee sites, but only 1 of 15 weedy levee sites.
Dissertation•
05 Mar 1994
27 Feb 1994
Patent•
18 Mar 1994
TL;DR: In this article, a composition and method of protecting plants otherwise susceptible to infestation by insects of the orders Lepidoptera and Coleoptera is presented, which can be used to protect plants.
Abstract: The present invention provides a composition and method of protecting plants otherwise susceptible to infestation by insects of the orders Lepidoptera and Coleoptera.
TL;DR: The infestation dynamics of Dioryctria sylvestrella were studied for 2 consecutive years, in both pruned and unpruned maritime pine, showing a significant positive correlation with the severity of pruning.
TL;DR: In this article, the utility of forest inventory data as an evaluation tool is shown by performing analyses equivalent to those performed by other researchers in smaller scale studies conducted on the Kenai Peninsula and comparing results.
Abstract: Forest inventory data collected in 1987 from the Kenai Peninsula, Alaska, were used to explore whether or not such data can be used to evaluate dynamics of a spruce bark beetle (Dendroctonusrufipennis (Kirby)) infestation there. The utility of the inventory data as an evaluation tool is shown by performing analyses equivalent to those performed by other researchers in smaller scale studies conducted on the Kenai Peninsula and comparing results. Analyses showed that extensive forest inventory data can be used to estimate areas of infestation and to establish relations among tree diameter, recent radial growth, tree stocking, state of beetle attack, and stage of infestation. Understanding of spruce bark beetle infestation dynamics on broad, regional scales, can be achieved while also obtaining extensive forest inventory data.
Journal Article•
TL;DR: An experiment was conducted during 1989-91 to study stability of 10 cultivars of bittergourd for economic traits.
Abstract: An experiment was conducted during 1989-91 to study stability of 10 cultivars of bittergourd (Momordica charantia L.) for economic traits.'Punjab 14' gave higher total (23.09 tonnes/ha) and marketable yield (20.33 tonnes/ha) and proved most stable for days taken to first harvest, days for 50% harvest and fruit weight. It also proved stable for total and marketable yield under favourable conditions. 'C 96' was most stable for fruits/plant and infestation by melon fruit-fly (Dacus cucurbitae Coq.) and 'NDBT 1 was most stable for fruit-fly infestation only.