Showing papers on "Infestation published in 1971"
TL;DR: Hereford cattle kept on a high-quality diet were studied over a treatment period of 11 weeks with the tick-infested animals being infested regularly with equal larval doses for each animal.
Abstract: This experiment was designed to measure the effects of infestation by B. microplus on cattle and to separate the effects of reduced food intake ("anorectic effect") from those due to the remaining factors of tick infestation ("specific effect"). Hereford cattle kept on a high-quality diet were studied over a treatment period of 11 weeks with the tick-infested animals being infested regularly with equal larval doses for each animal.
64 citations
TL;DR: Using autoradiography it was shown that saliva ofT.
Abstract: Using autoradiography it was shown that saliva of T. urticae injected into the plant was transported to the growing regions. Indications were found that the two-spotted spider mite has an active phosphate metabolism. A local mite infestation on a bean pla~t caused an increased transport of phosphates to the top leaves and the roots. At the same time an increase of P transport towards the infested leaf was ascertained. It appeared that this was not caused by a wound reaction but by a physiological influence of the mites via their saliva secretion into the host plant. A mite population in bean interferes with the equilibrium of the growth promoting substances present in the plant. Under certain conditions a slight infestation of mites (1--4 ~ per crn 2) causes a growth stimulation. A heavier infestation (more than 10 ~ per cm ~) causes growth inhibition. Using thin layer chromatography an indole compound was found in the mites. In bean plants infested with mites the amount of gibberellin appeared to be markedly increased.
41 citations
TL;DR: Australian Illawarra Shorthorn steers developed resistance at a second and third infestation which waned at a fourth infestation, but individual steers displayed developing resistance throughout the four infestations.
Abstract: Purebred Sahiwal cattle acquired resistance to Boophilus microplus in a similar manner to crossbred Sahiwal cattle as previously reported. The purebred entire males and females were more resistant than a control group of crossbred steers because they dropped significantly fewer replete ticks than the crossbreds at the third and fourth, but not at the first and second infestations. Adult female ticks dropped by purebred animals were significantly lighter than those dropped by crossbred animals at the fourth infestation only. There was no significant difference in the numbers of eggs laid and hatched from ticks dropped by purebred and crossbred animals. Australian Illawarra Shorthorn steers developed resistance at a second and third infestation which waned at a fourth infestation, but individual steers displayed developing resistance throughout the four infestations. Day of modal drop of replete female ticks appeared to be affected by breed, and developing resistance or season.
36 citations
TL;DR: The conclusion is that the eugregarine infestation apparently reduces the longevity of adults when other conditions are sub-optimum.
Abstract: Adults of the damselfly Pyrrhosoma nymphula (Sulzer) were to a great extent found to have their midgut infected with a eugregarine Hoplorhynchus oligacanthus (Siebold). Heavy infestation seriously damaged the gut epithelium, and the viability of the host was estimated to be reduced. Marking experiments have revealed that individuals which attained great adult age were either lightly infected or non-infected, or they were thought to have been infected late in their adult life. The conclusion is that the eugregarine infestation apparently reduces the longevity of adults when other conditions are sub-optimum.
32 citations
21 citations
TL;DR: Populations of adult Popillia japonica Newman were reduced at least 50% at Nantucket, Massachusetts, by 3 years of mass trapping.
Abstract: Populations of adult Popillia japonica Newman were reduced at least 50% at Nantucket, Massachusetts, by 3 years of mass trapping. Twenty-eight species of Scarabaeidae other than Japanese beetles were taken. Arthropods other than Japanese beetles and bumble bees captured in 1965 are listed by order.
18 citations
TL;DR: Infestation of T. crassus did not affect the ratio weight: length of the fish, and Cyathocephalus truncatus was absent from all regulated lakes, its intermediate host Gammarus being highly sensitive to changes provoked by the regulation.
Abstract: The occurrence of Triaenophorus crassus and Cyathocephalus truncatus (Cestoda) in whitefish Coregonus was compared in non-regulated and regulated lakes. In non-regulated lakes, Coregonus peled and C. oxyrhynchus with a high number of gilirakers and a high frequency of plankton in the diet were most heavily infested. In regulated lakes differences between Coregonus spp. were absent or small. C. pidschian and C. nasus with a low number of gillrakers feed on plankton to a much higher extent in regulated lakes and become more heavily infested. In populations with low infestation no correlation was found between frequency of T. crassus and age of fish, but in populations with high infestation such a correlation was established (up to 7 years old fish). Infestation of T. crassus did not affect the ratio weight: length of the fish. C. truncatus was absent from all regulated lakes, its intermediate host Gammarus being highly sensitive to changes provoked by the regulation.
16 citations
15 citations
TL;DR: Nymph-infested plants grew taller and showed altered patterns of squaring, flowering, and bolling, as compared with noninfested controls, but no significant reductions in seed cotton yield or lint quality were detected.
Abstract: Damage to individual cotton plants ‘Deltapine 16’, by uniform and continuous infestations of 1 late-stage nymph or adult male Lygus hesperus Knight per cage during 4 infestation periods was studied at Tucson, Arizona, in 1969. Nymph-infested plants grew taller and showed altered patterns of squaring, flowering, and bolling, as compared with noninfested controls, but no significant reductions in seed cotton yield or lint quality were detected. Nymph-infested plants yielded lower percentage weights of lint and higher percentage weights of seed. Plants infested with nymphs from the time of 1st square until Aug. 16 had significantly increased numbers of main stem vegetative branches. Plants infested with adults from the time of 1st square until 1st bloom showed altered patterns of squaring and flowering but no significant yield reductions. Lint quality and monetary value were lower on plants exposed to adults during the late infestation period from July 26 to Aug. 16.
14 citations
Journal Article•
TL;DR: Sixty-four percent of the Brazos River flood plain upstream from Possum Kingdom Lake to the confluence of its Salt and Double Mountain forks is occupied by woody phreatophytes, and saltcedar dominated communities are found on 36% and mesquite on 17%.
Abstract: Sixty-four percent of the Brazos River flood plain upstream from Possum Kingdom Lake to the confluence of its Salt and Double Mountain forks is occupied by woody phreatophytes. Saltcedar dominated communities are found on 36% and mesquite on 17%. Saltcedar acreage increased significantly from 1940 to 1969, but mesquite did not. At 1969 densities, these two species used approximately 5 1,000 acre feet of water annually along this expanse of the river.
TL;DR: Earias fobia infests cotton and a few other malvaceous plants but the degree of their infestation varies, as infostation of a plant by an insect depends upon the cxtent to which the plant can maintain and propagate the insect populations.
Abstract: Earias fobia inf'ests cotton and a few other malvaceous plants CFLETcrrER and )vlrsRA, 1920; DEsiipANpE and NADKARNy, 1936; KHAN et at., 1945; CHERiAN and KyLAsAM, l947) but the degree of their infestation varies, Thc reasons for this are not adequatcly known, As infostation of a plant by an insect depends upon the cxtent to which the plant can maintain and propagate the insect populations, the influence of diets from diflhrent plants on survival and cggproduction ef E. .fabia has been exainined te
TL;DR: An estimate is made of the number of tracer sheep required satisfactorily to demonstrate changes of various order in pasture infestation due to season, climate or control measures under the ecological conditions pertaining on reclaimed western blanket peat in Ireland.
Dissertation•
01 Jan 1971
TL;DR: The infestation level and species composition of the fleas in two sub populations of the field voles were studied in two different habitats: in the drier habitat there was a slightly heavier infestation than in the moist habitat, and a few differences in species composition were observed.
Abstract: In 1968 and 1969, 2 078 specimens of fleas were collected from 501 live-trapped field voles, Microtus agrestis (L.) on an estate in southern Finland. The fleas belonged to 12 species, the dominant species being Megabothris walkeri (Rothsch.) (44.2 %) and Ctenophthalmus agyrtes fennicus Peus (37.l %). Seasonal changes in the percentage infestation and mean infestation per host were observed: one maximum occurred in spring and another in autumn. Examination of the species composition of the fleas at different seasons revealed some species with a restricted seasonal occurrence and others occurring throughout the year. An excess of females was observed in Ctenoph thalmus agyrtes fennicus and C. uncinatus uncinatus (Wagner). In Megabothris walkeri the total sex ratio was roughly 1:1. Reproductive males were the host group most heavily infested. Reproductive females were more heavily infested than subadult and juvenile hosts. Among the non reproductive animals there was no difference in numbers of fleas between the sexes. Data on seasonal fluctuations in the infestation of these different host categories are presented. The infestation level and species composition of the fleas in two sub populations of the field voles were studied in two different habitats. In the drier habitat there was a slightly heavier infestation than in the moist habitat. A few differences in species composition were observed, too.
TL;DR: Differential varietal reaction to injury by larvae of Diabrotica undecimpunctata howardi Barber, of 9 previously tested lines and 3 commercial cultivars of peanuts, Arachis hypogaea L., was measured at levels of infestation in the greenhouse.
Abstract: Differential varietal reaction to injury by larvae of Diabrotica undecimpunctata howardi Barber, of 9 previously tested lines and 3 commercial cultivars of peanuts, Arachis hypogaea L., was measured at levels of infestation in the greenhouse. Significant differences in percent injured fruit were found between lines in immature, mature, and total fruit at the 25 and 50 larvae/basket level of infestation. High levels of injury resulted at the 100 larvae/basket level in the 3 categories of fruit, but differences (range 30.2-49.6) in mature fruit were not significant. Differences in percent injured fruit were found between levels of infestation.
TL;DR: In Surinam insecticides are not used against stem borers and a further depressive action can be produced by the side-effect of insecticides commonly applied against non-borer pests such as waterweevils, leafminers, leaf-eating caterpillars, delphacids and seed bugs.
Abstract: By comparing the mean panicle weight (a) per uninfested stem to the mean panicle weight (b) per infested stem, yield loss can be calculated from the equation loss=(a−b) n.p. where n represents the number of panicles per sq.m. or ha and p the percentage of infestation. Losses caused byRupela turn out to be small or moderate. Larval development takes place within one internode and the nodal septum is not destroyed. Chemical control measures are not considered to be economically feasible. Damage inflicted byDiatraea may be considerable. Injury is not limited to one internode and several nodes are often pierced. Since the more serious infestations by this borer mainly seem to occur randomly in the form of local erruptions, forecasting the outbreak of this insect in a rice region probably does not give a sufficient clue for a pin-pointed chemical control. A preventive control over the whole area is too expensive. Thus in Surinam insecticides are not used against stem borers. Separated sowing and harvesting periods with the shortest duration possible, and stubble burning and clean cultivation of fallow fields have proved valuable in restricting borer infestation. A further depressive action can be produced by the side-effect of insecticides commonly applied against non-borer pests such as waterweevils, leafminers, leaf-eating caterpillars, delphacids and seed bugs.
TL;DR: In this paper, the authors used dichlorvos-impregnated resin pellets into 42·5 m3 (1500 ft3) chambers containing insect-free flour packaged in cotton sheeting, and in multiwall paper bags stacked at various distances from similar bags of infested flour.
TL;DR: In this article, PIGEON MITES and HUMAN INFESTATION were discussed in the context of New Zealand Entomologist. But they focused on the piglet species.
Abstract: (1971). PIGEON MITES AND HUMAN INFESTATION. New Zealand Entomologist: Vol. 5, No. 1, pp. 90-92.
TL;DR: A survey of ticks, including information on the prevalence of infestation, species, and stages of tick development, was made from September 1965 to November 1966 on stray dogs electrocuted at Kampong Java Road Animal Infirmary, Singapore as mentioned in this paper.
Abstract: A survey of ticks, including information on the prevalence of infestation, species, and stages of tick development, was made from September 1965 to November 1966 on stray dogs electrocuted at Kampong Java Road Animal Infirmary, Singapore. While meteorologic parameters for the areas from which the dogs came seemed to have little effect on observable dog-tick relationships, systematic removal of stray dogs decreased the proportion of dogs infested with one or more ticks from a high of 52% in October 1965 to a low of 19% in October 1966. Seventy-one to 81% of the variability or the data could be accounted for by using the logarithms of the cumulative numbers of dogs destroyed during the survey as the only predictor variable. During the 14-month survey 949 dogs were examined and 7020 ticks were recovered.
TL;DR: This radiographic process, most appropriate to quarantine practice, is presented andOptimal exposures were determined for seeds of 46 plant species and the reliability of radiographic counts of infestation was controlled.
Abstract: In quarantine inspection it is particularly important to use reliable and rapid testing methods for revealing internal infestation of seeds. Generally, it is impossible to diagnose correctly hidden infestation, at a low level, by means of traditional inspection test methods. The X-ray technique, however, has considerable merit in the rapid and objective detection of insects living inside seeds. This radiographic process, most appropriate to quarantine practice, is presented. Optimal exposures were determined for seeds of 46 plant species. The reliability of radiographic counts of infestation was controlled by a model-experiment, in which a very high correlation (r =−0.986) was found between the rate of infestation in the samples and the number of seeds to be tested from the sample. On a certain level by the regression equation (y = 7691–2468 log. x) it is possible to determine the number of seeds which have to be tested in order to obtain the real value of infestation.
TL;DR: Corn grain containing different levels of infestation of Sitophilus zeamais Motschulsky were stored varying lengths of time to determine the effect of the initial maize weevil infestation on subsequent damage to the grain in storage.
Abstract: Corn grain containing different levels of infestation of Sitophilus zeamais Motschulsky were stored varying lengths of time to determine the effect of the initial maize weevil infestation on subsequent damage to the grain in storage. Grain with initial kernel infestations ranging from 0 to 8% were included in the study. Results of tests showed that grain damage in storage caused by this species was directly related to amount of infestation at time of storage. Grain that contained no infestation when storage began was less than 1% damaged after 7 months. Grain with 1.2, 3.5, and 6.3% infestation when stored was 34.7, 43, and 63% damaged, respectively, after 7 months. The grain test weight decreased in proportion to the amount of insect infestation that developed. Angoumois grain moth infestation developed earlier in corn that contained the higher levels of maize weevil infestations than in corn that contained no weevil infestation when stored.
TL;DR: Studies indicate that Paramyelois transitella (Walker) is able to invade rapidly an almond orchard where the within-the-orchard source has been removed, and there may be economic advantages to the sanitation practice of cleaning almond orchards of old nuts.
Abstract: Studies indicate that Paramyelois transitella (Walker) is able to invade rapidly an almond orchard where the within-the-orchard source has been removed. This fact was indicated by the presence of eggs deposited on nuts artificially hung in the trees. Complete removal of all old nuts from the orchard insured that oviposition was effected by immigrating moths. The greatest amount of oviposition occurred in the half of the orchard that was adjacent to the more heavily infested surrounding areas. The orchard was invaded in all quarters within 39 days during the spring flight; 61% of the infestation occurred within 12 days. There may be economic advantages to the sanitation practice of cleaning almond orchards of old nuts. At harvest, 4.9% of the nuts from the experimental orchard contained navel orangeworm damaged kernels; an adjacent orchard had 7.9% damaged kernels.
Journal Article•
TL;DR: Effects of balsam woolly aphid infestation on the concentration of ethanol-soluble and -insoluble carbohydrates were investigated in four age classes of needles and six ageclasses of twigs of grand fir, before and after bud break.
Abstract: Effects of balsam woolly aphid infestation on the concentration of ethanol-soluble and -insoluble carbohydrates were investigated in four age classes of needles and six age classes of twigs of grand fir, before and after bud break.In March, before bud break, sugars made up about two-thirds of the total carbohydrate content of the foliage. Aphid infestation did not affect the concentration of sugars in needles but reduced starch by 28%. In twigs, sugar concentrations were less in infested trees while starch concentrations were unaffected. Both older needles and twigs contained higher concentrations of starch than younger needles and twigs.After bud break in June, starch constituted the major form of carbohydrate, accounting for 65% of the total carbohydrate in non-infested foliage and 53% in infested foliage. Total carbohydrate content increased over that in March, in both infested and non-infested foliage, but the non-infested tissue showed the greatest increase. Starch content of infested foliage was red...
TL;DR: The authors made a study on the species and distribution of helminths in Korean native cattle, and the feces and internal organs from 1,755 heads were examined in slaughter plants of Taejon district, finding high rate of infestation throughout all districts of the country, especially Cheju island with a significant higher rate.
Abstract: The authors made a study on the species and distribution of helminths in Korean native cattle. The feces and internal organs from 1,755 heads were examined in slaughter plants of Taejon district. The results are summarized as follows. 1. Distribution and infestation rate of helminths among the collected samples are, Paramphistomum spp. 68.4%, Fasciola spp. 48%, Eurytrema spp. 23.5%, Moniezia spp. 8%, Dictyocaulus spp. 3.5%, Trichostrongylus spp. 12.4%, and other species 26.8%, respectively. 2. In 36.4% of ths cases, single infestation was seen and in 31.5%, 18.0%, and 14.0 % mixed infestation of double, triple, and quadruple or more species were seen, respectively. 3. Geographical analysis of infested helminths in the native cattle indicates: a. Among the trematoda order, Paramphistomum spp. and Fasciola spp. showed high rate of infestation throughout all districts of the country, especially Cheju island with a significant higher rate. Central district (Taejon) was higher in number of native cattle infested with Fasciola spp. than any other district of the country investigated. b. The rate of infestation with cestoda also showed to be higher in Cheju island than any other district of main land, but the rate of infestation with other nematoda showed no geographical difference.