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Infestation
Kinds of Infestation Terms modified by Infestation Selected AbstractsHost plant changes produced by the aphid Sipha flava: consequences for aphid feeding behaviour and growthENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002W.L. Gonzáles Abstract Induced plant responses may affect the behaviour and growth of the attacking herbivore insect. The aphid Sipha flava (Forbes) produces reddish spots on the infested leaf of its host plant Sorghum halepense (L.). In order to assess the consequences on the aphid of this presumptive induced plant response, we studied the feeding behaviour and growth of S. flava on previously infested and non-infested leaves of S. halepense. Considering that the reddish pigment could play a defensive role, its effect on aphid survival was determined in artificial diets. In addition, changes in the histology of the leaf and the chemical nature of the induced pigment were also studied. Aphids devoted a significantly shorter total time to non-penetration activities in infested than in non-infested leaves. Time before the first phloem ingestion tended to be shorter in infested leaves. The mean relative growth rate of S. flava nymphs was significantly higher on infested than on non-infested leaves. Survival of aphids on diet containing the reddish extract was not significantly different from that on the control diet. Infestation of S. halepense by S. flava produced a reddish coloration in the leaf, which was identified as an anthocyanin by UV-visible spectrometry. Light microscopy showed that only mesophyll cells of previously infested plants presented swelled, dispersed, and heterogeneously stained chloroplasts with a higher accumulation of starch granules, no grana arranged in stacks, and reduction in the amount of inner membranes (thylakoids), relatively to chloroplasts of non-infested leaves. Scanning electron micrographs of leaf surface revealed reduced presence of crystalline epicuticular waxes of epidermal cells in infested leaves as compared to non-infested ones. The main conclusion is that the attack of S. flava to S. halepense leaves induced plant susceptibility where aphid feeding behaviour and growth were both enhanced on previously infested leaves. [source] Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of SugarcaneENTOMOLOGICAL RESEARCH, Issue 3 2005Abdul KHALIQ ABSTRACT Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval. [source] Disruption of an exotic mutualism can improve management of an invasive plant: varroa mite, honeybees and biological control of Scotch broom Cytisus scoparius in New ZealandJOURNAL OF APPLIED ECOLOGY, Issue 2 2010Quentin Paynter Summary 1.,A seed-feeding biocontrol agent Bruchidius villosus was released in New Zealand (NZ) to control the invasive European shrub, broom Cytisus scoparius, in 1988 but it was subsequently considered unable to destroy sufficient seed to suppress broom populations. We hypothesized that an invasive mite Varroa destructor, which has caused honeybee decline in NZ, may cause pollinator limitation, so that the additional impact of B. villosus might now reach thresholds for population suppression. 2.,We performed manipulative pollination treatments and broad-scale surveys of pollination, seed rain and seed destruction by B. villosus to investigate how pollinator limitation and biocontrol interact throughout the NZ range of broom. 3.,The effect of reduced pollination in combination with seed-destruction was explored using a population model parameterized for NZ populations. 4.,Broom seed rain ranged from 59 to 21 416 seeds m,2 from 2004 to 2008, and was closely correlated with visitation frequency of honeybees and bumblebees. Infestation of broom seeds by B. villosus is expected to eventually reach 73% (the average rate observed at the localities adjacent to early release sites). 5.,The model demonstrated that 73% seed destruction, combined with an absence of honeybee pollination, could cause broom extinction at many sites and, where broom persists, reduce the intensity of treatment required to control broom by conventional means. 6.,Nevertheless, seed rain was predicted to be sufficient to maintain broom invasions over many sites in NZ, even in the presence of the varroa mite and B. villosus, largely due to the continued presence of commercial beehives that are treated for varroa mite infestation. 7.,Synthesis and applications. Reduced pollination through absence of honeybees can reduce broom seed set to levels at which biocontrol can be more effective. To capitalize on the impact of the varroa mite on feral honeybees, improved management of commercial beehives (for example, withdrawal of licences for beekeepers to locate hives on Department of Conservation land) could be used as part of a successful integrated broom management programme at many sites in NZ. [source] Infestation of trees by lianas in a tropical forest in Amazonian PeruJOURNAL OF VEGETATION SCIENCE, Issue 6 2008Geertje M.F. van der Heijden Abstract Question: In Amazonian moist forest, four questions arose: 1. Do tree species differ in their susceptibility to lianas? 2. What host tree traits (branch-free bole height, growth rate, bark type, leaf length and adult stature) are correlated with the susceptibility of tree species to lianas infesting the trunk and the crown? 3. To what extent do spatial variables (proximity to liana-infested trees and the light environment of the tree crown) affect the likelihood of liana infestation? 4. Are spatial variables or tree traits relatively more important in influencing the susceptibility of trees to lianas? We address all questions separately for trunk and crown infestation. Location: Tambopata Nature Reserve, Peru. Methods: We collected information on liana infestation, tree morphological traits, growth, light-environment and position for 3675 trees in seven 1-ha permanent sample plots. We separated trunk from crown infestation and used correlation and logistic regression analyses for tree species and individual tree-level analyses, respectively. Results: Half of all trees were colonised by at least one liana. Of 41 relatively common dicot tree species, at least five have significantly greater and three significantly lower crown infestation rates than expected by chance. Trunk and crown infestation are influenced by different host traits , trunk infestation was only affected by bark type, while crown infestation is reduced when trees are fast-growing, tall, have low-density wood, long branch-free boles and long leaves. The likelihood of both trunk and crown infestation increases for trees growing in close proximity to another liana-infested tree, but is invariant with the light environment of tree crowns. Conclusion: Crown and trunk infestation have not been properly distinguished before; it is important to do so as the factors determining the different modes of infestation differ fundamentally. The association between crown infestation and tree traits suggests that increases in liana dominance in Amazonian forests could cause changes in forest composition, including favouring faster growing tree species with low density wood, potentially reducing the carbon stored by mature forests. [source] The immunology of susceptibility and resistance to scabiesPARASITE IMMUNOLOGY, Issue 8 2010S. F. WALTON Summary The transmission of scabies occurs with the burrowing of Sarcoptes scabiei var. hominis mites into the skin. Infestation invariably leads to the development of localized cutaneous inflammation, pruritis and skin lesions. Classical transmission studies document an initial increase in S. scabiei numbers subsequent to primary infestation with a gradual reduction as host immunity develops. However, certain individuals fail to control infection and develop severe crusting of the skin, accompanied with extremely high mite burdens, elevated antibody levels and eosinophilia. These individuals have the nonhealing form of the human disease known as crusted scabies. The genetic predisposition for susceptibility or resistance to S. scabiei infection in humans is hypothesized to correlate with the dominance of an IgE-driven Th2 response in severe disease or an interferon-,-dominated Th1 response that promotes parasite control. However, recent data reveals complexities in cytokine regulation in the skin and the mechanisms of acquired resistance and immune escape. In this review, we consider the recent immunological and biomolecular advances in understanding the human host immune response to S. scabiei infestations in the context of earlier studies and attempt to reconcile apparent differences and emphasize those aspects of the Th1/Th2 model that are supported or refined. [source] Pest reduction services by birds in shade and sun coffee in JamaicaANIMAL CONSERVATION, Issue 2 2010M. D. Johnson Abstract The reduction of insect pests by birds in agriculture may provide an incentive for farming practices that enhance the conservation value of farms for birds and other wildlife. We investigated pest reduction services by insectivorous birds on a coffee farm in Jamaica, West Indies. Our results suggest that birds reduced insect pests on our study site. Infestation by the coffee berry borer Hypothenemus hampei, the world's most damaging insect pest in coffee, was significantly elevated on coffee shrubs from which birds were experimentally excluded from foraging. Overall, we estimated the economic value of the reduction of coffee berry borer by birds on the 18 ha farm to be US$310 ha,1 for the 2006 harvest season. These results provide additional evidence that birds can reduce numbers of economically damaging pests and enhance crop yields in coffee farms. Differences in the magnitude of pest reduction within the farm may have resulted from variation in shade management and surrounding habitats, and these factors merit further investigation. [source] Infestation of coconut fruits by Aceria guerreronis enhances the pest status of the coconut moth Atheloca subrufellaANNALS OF APPLIED BIOLOGY, Issue 2 2009S.W.J. De Santana Abstract The coconut mite, Aceria guerreronis (Acari: Eriophyidae) and the coconut moth, Atheloca subrufella (Lepidoptera: Phycitidae), exploit the same habitat,meristematic region underneath the coconut fruit perianth. The coconut fruit perianth, however, is a tight structure allowing free colonisation of the meristematic region of the fruit only by small arthropods such as the eriophyid and tarsonemid mites. Fruits infested by the mites develop different levels of necrosis around the perianth providing access to colonising larvae of the coconut moth, which bore the fruit under the perianth resulting in fruit abortion. Based on field observations, we hypothesise that A. subrufella will colonise coconut fruits only if they exhibit damage on the perianth such as the necrosis caused by the coconut mite. Fruits with and without necrosis were collected from different production areas located in three different states along the Brazilian Atlantic coast and inspected for infestation with coconut moth larvae. In the laboratory, coconut fruits with and without necrosis were offered to moths for oviposition preference and tested for colonisation by neonate and third instar larvae. The results showed that the moths showed no preference for fruits with or without necrosis for oviposition and, hence, neonate larvae have to go under the perianth bract to reach the meristematic region of the fruit. However, neonate larvae were unable to colonise fruits without necrosis (0%) compared to 23% and 60% of fruit colonisation success when exhibiting mite necrosis or mechanical damage, respectively. Similar results were found with respect to older coconut moth larvae. Thus, the data support the hypothesis that the indirect interaction through previous fruit colonisation and necrosis caused by the coconut mite allows the larvae of A. subrufella to be a key pest of coconut fruits. [source] Simulation Modeling as a Tool for Understanding the Landscape Ecology of Southern Pine Beetle Infestations in Southern Appalachian ForestsGEOGRAPHY COMPASS (ELECTRONIC), Issue 3 2008David Martin Cairns The forests of southeastern North America are influenced by a variety of disturbances including fire and insect outbreaks. In this paper, we discuss the role of disturbances in structuring forest landscapes with particular emphasis placed on the reciprocal interaction between forest structure and outbreaks of the southern pine beetle (Dendroctonus frontalis Zimmermann). We highlight work in which we are currently involved to illustrate the importance and utility of using spatially explicit forest modeling as a tool for understanding forest,insect interactions and its potential role in determining management strategies. [source] Essential Oil of,Aegle marmelos,as a Safe Plant-Based Antimicrobial Against Postharvest Microbial Infestations and Aflatoxin Contamination of Food CommoditiesJOURNAL OF FOOD SCIENCE, Issue 6 2009Priyanka Singh ABSTRACT:, The essential oil of,Aegle marmelos,L. Correa (Rutaceae) showed strong fungitoxicity against some storage fungi-causing contamination of foodstuffs. The oil also showed efficacy as aflatoxin suppressor at 500 ,L/L as it completely arrested the aflatoxin B1 production by the toxigenic strains (Navjot 4NSt and Saktiman 3NSt) of,Aspergillus flavus,Link. Keeping in view the side effects of synthetic fungicides,,A. marmelos,oil may be recommended as an antimicrobial of plant origin to enhance the shelf life of stored food commodities by controlling the fungal growth as well as aflatoxin secretion. This is the 1st report on aflatoxin B1 inhibitory nature of this oil.,A. marmelos,oil may be recommended as a novel plant-based antimicrobial in food protection over synthetic preservatives, most of which are reported to incite environmental problems because of their nonbiodegradable nature and side effects on mammals. The LD50 of,Aegle,oil was found to be 23659.93 mg/kg body weight in mice (Mus musculus,L.) when administered for acute oral toxicity showing nonmammalian toxicity of the oil. GC-MS analysis of the oil found DL-Limonene to be major component. [source] Factors Related to Missed Diagnosis of Incidental Scabies Infestations in Patients Admitted Through the Emergency Department to Inpatient ServicesACADEMIC EMERGENCY MEDICINE, Issue 9 2010Ming-Yuan Hong MD ACADEMIC EMERGENCY MEDICINE 2010; 17:958,964 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, Scabies is highly contagious and requires prompt diagnosis and implementation of infection control measures to prevent transmission and outbreaks. This study investigated the clinical and administrative correlates associated with missed diagnosis of scabies in an emergency department (ED). Methods:, This was a retrospective study of patients with incidental scabies infestations who were admitted to a university hospital via the ED during a 4-year period. Results:, A total of 135 inpatients were identified as having scabies; among them, 111 patients (82%) had visited the ED. Scabies were diagnosed during the ED stay in 39 of 111 patients (35%), while the diagnosis was missed in the ED in 72 patients (65%). Although no geographic clusters suggestive of nosocomial scabies transmission were registered, 160 medical workers and one hospitalized patient received prophylactic treatment due to direct skin-to-skin contact with inpatient scabies cases during the study period. Overcrowding (odds ratio [OR] = 8.4; 95% confidence interval [CI] = 1.9 to 38.0) and time constraints (OR = 8.2; 95% CI = 1.9 to 34.7) in the ED were associated with a missed diagnosis of scabies during ED stay. Patients with lower illness severity scores were at higher risk for failure to diagnose and to treat scabies prior to hospital admission (OR = 5.7; 95% CI = 1.6 to 20.9). Conclusions:, Missed diagnoses of scabies during ED stay may result in nosocomial spread and increase the unnecessary use of prophylactic treatments. ED overcrowding, time constraints, and less severe illness compromise ED recognition of scabies. Health care workers should be especially alert for signs of scabies infestations under these conditions. [source] Treatment of head liceDERMATOLOGIC THERAPY, Issue 4 2009Stephanie A. Diamantis ABSTRACT Pediculosis capitis, or head lice, is a common infestation among children worldwide. Multiple therapies exist for the treatment of this condition, including topical pediculicides and oral medications. When used in combination with environmental decontamination, these drugs can be very effective in eradicating head lice infestation without significant adverse events. The present study discusses the use of available over-the-counter and prescription treatments, including pyrethroids and permethrin, lindane, malathion, ivermectin, and trimethoprim-sulfamethoxazole, in the treatment of head lice. [source] Oviposition preferences of Maculinea alcon as influenced by aphid (Aphis gentianae) and fungal (Puccinia gentianae) infestation of larval host plantsECOLOGICAL ENTOMOLOGY, Issue 1 2009ERVIN ÁRNYAS Abstract 1.,The influence of infestation of the larval host plant Gentiana cruciata on the egg-laying preferences of the xerophilous ecotype of Alcon Blue butterfly (Maculinea alcon) was studied in a semi-dry grassland area (Aggtelek Karst Region, Northern Hungary). 2.,We examined whether oviposition patterns of females differed when G. cruciata stems were uninfested compared with when they were infested by an aphid (Aphis gentianae) or a rust (Puccinia gentianae) species. 3.,Females laid more than 90% of their eggs on fertile, uninfested G. cruciata stems, although these stems comprised only , 50% of the total stems available. Stems infested by aphids were similar to uninfested ones in properties that had a strong correlation with egg numbers, and yet there were significantly fewer eggs on infested stems than on intact ones. 4.,Females never laid eggs on parts of Gentiana stems infested by aphids, and the presence of Lasius paralienus ants, which have a mutualistic interaction with Aphis gentianae, did not increase the repulsive effect of aphids. Infection of Gentiana by Puccinia did not influence the egg-laying behaviour of females, even though the flowers and buds of infested stems exhibited a delayed development. 5.,Aphid infestation can influence butterfly oviposition patterns through both direct and indirect effects. The presence of aphids directly excluded oviposition, but our data also indicated the possibility of an indirect effect of aphid infestation. Stems that had no aphids at the last egg counting, but were infested prior to it, had significantly fewer eggs than those that were never infested. [source] Parasitism by the mite Trombidium breei on four U.K. butterfly speciesECOLOGICAL ENTOMOLOGY, Issue 6 2002L. Conradt Abstract 1. The incidence of parasitism by larvae of the mite species Trombidium breei was reported in one population of the lycaenid butterfly Polyommatus icarus, four populations of the satyrine butterfly Maniola jurtina, one population of the satyrine butterfly Aphantopus hyperanthus, and two populations of the satyrine butterfly Pyronia tithonus, as well as on one specimen of the dipteran Alophorus hemiptera. A considerable proportion of butterflies (11-50%) was infested in all study populations. 2. The pattern of infestation was examined in detail in M. jurtina. Males had a significantly higher incidence of infestation than females, and middle-aged butterflies had a higher incidence of infestation than old or young butterflies. The incidence of infestation peaked in the middle of the flight season, and this seasonal effect was independent of the effect of butterfly age. 3. Using a model based on capture-recapture data, it was estimated that a hypothetical ideal male M. jurtina that lives exactly the mean expected lifespan of 9-10 days has an approximately 75% chance of becoming infested with mites at least once during its lifetime, a mean time to first infestation of 3-4 days, and an average infestation persistence time of 2-3 days. 4. Capture-recapture data failed to show any effect of mite infestation on the lifespan or within-habitat movement rate of M. jurtina. 5. In experiments in which individual butterflies were taken out of their normal habitat and released, M. jurtina and P. tithonus that were infested with mite larvae did not differ from uninfested individuals in the efficiency with which they returned to suitable habitat. Thus, parasitism by T. breei larvae had no detectable effects on flight performance or orientation ability. 6. The results suggest that trombidiid mite larvae have limited potential in the biological control of insect pests. [source] Holly leaf-miners on two continents: what makes an outbreak species?ECOLOGICAL ENTOMOLOGY, Issue 2 2001Sabine Eber Summary 1. Some herbivore species periodically undergo damaging, high-density outbreak phases followed by less damaging low-density phases. Others maintain steady, low to moderate density levels that do little damage to their hosts. 2. Two closely related holly leaf-miner species were compared that share many ecological traits and have very similar life cycles, but only one of which exhibits outbreaks. Phytomyza ilicicola in the eastern U.S.A. varied widely in mortality and infestation levels, reaching local densities of over 10 mines per leaf. In contrast, Phytomyza ilicis in the U.K. showed low infestation and high mortality at all sites. Using data from the literature and from field studies, the factors responsible for these contrasting dynamics were sought. 3. Phytomyza ilicicola oviposits into the leaf lamina, and experiences weak larval competition only at high densities. Phytomyza ilicis oviposits into the leaf midrib, which leads to high mortality of young larvae before mine formation. Multiply mined leaves were therefore very common in P. ilicicola but rare in P. ilicis. 4. Differences in the parasitoid complexes of the two systems accounted for further differences in survival to adulthood. The main (larval) parasitoid, which was found to impose high, density-dependent mortality on P. ilicis, is missing on P. ilicicola. It is replaced by an egg,pupal parasitoid, which varies in its impact at differe,t sites. Multiple emergence of adults from multiply mined leaves is therefore widespread in P. ilicicola but does not occur in P. ilicis. 5. The differences in oviposition behaviour and in the parasitoid complexes are likely to allow P. ilicicola to outbreak when habitat conditions are favourable, while P. ilicis is always tightly regulated. [source] Females of the European beewolf preserve their honeybee prey against competing fungiECOLOGICAL ENTOMOLOGY, Issue 2 2001Erhard Strohm Summary 1. Females of the European beewolf Philanthus triangulum (Hymenoptera, Sphecidae) provision brood cells with paralysed honeybees as larval food. Because brood cells are located in warm, humid locations there is a high risk of microbial decomposition of the provisions. Low incidence of fungus infestation (Aspergillus sp.) in nests in the field suggested the presence of an anti-fungal adaptation. 2. To test whether the paralysis caused the protection from fungus infestation, the timing of fungus growth on bees that were freeze-killed, paralysed but not provisioned, and provisioned regularly by beewolf females was determined. Fungus growth was first detected on freeze-killed bees, followed by paralysed but not provisioned bees. By contrast, fungus growth on provisioned bees was delayed greatly or even absent. Thus, paralysis alone is much less efficient in delaying fungus growth than is regular provisioning. 3. Observations of beewolves in their nests revealed that females lick the body surface of their prey very thoroughly during the period of excavation of the brood cell. 4. To separate the effect of a possible anti-fungal property of the brood cell and the licking of the bees, a second experiment was conducted. Timing of fungus growth on paralysed bees did not differ between artificial and original brood cells. By contrast, fungus growth on bees that had been provisioned by a female but were transferred to artificial brood cells was delayed significantly. Thus, the treatment of the bees by the female wasp but not the brood cell caused the delay in fungus growth. 5. Beewolf females most probably apply anti-fungal chemicals to the cuticle of their prey. This is the first demonstration of the mechanism involved in the preservation of provisions in a hunting wasp. Some kind of preservation of prey as a component of parental care is probably widespread among hunting wasps and might have been a prerequisite for the evolution of mass provisioning. [source] Nitrogen fertilization effects on Myzus persicae aphid dynamics on peach: vegetative growth allocation or chemical defence?ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2010Marie-Hélène Sauge Abstract Plant nitrogen (N) fertilization is a common cropping practice that is expected to serve as a pest management tool. Its effects on the dynamics of the aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) were examined on young peach [Prunus persica (L.) Batsch (Rosaceae)] trees grown under five N treatments, ranging from N shortage to supra-optimal supply for growth. Aphid population increased over time at the three intermediate N levels. It remained stable at the lowest N level and decreased at the highest N level. Four weeks after the start of infestation, the number of aphids displayed a parabolic response to N level. The relationships between N status and parameters of plant vegetative growth (stem diameter) or biomass allocation (lateral-total leaf area and root-shoot ratio) were consistent with responses proposed by models of adaptive plasticity in resource allocation patterns. However, the variation in plant growth predicted aphid population dynamics only partially. Whereas aphid number was positively correlated with plant N status and vegetative growth up to the intermediate N level, it was negatively correlated with plant N status above this level, but not with vegetative growth. The concentrations of primary and secondary (plant defence-related) metabolites in the plant shoots were modified by N treatments: amino acids (main nutritional resource of aphids) and prunasin increased, whereas chlorogenic acid decreased with increasing N availability. Constitutive changes in plant chemistry in response to N fertilization could not directly explain the reduced aphid performance for the highest N level. Nevertheless, the indirect effect of N on the induction of plant defence compounds by aphid feeding warrants further investigation. The study focuses on the feasibility of handling N fertilization to control M. persicae in orchards, but findings may also be relevant for our understanding of the physiological relationships between the host's nutritional status and the requirements of the insect. [source] Can late summer Landsat data be used for locating Asian migratory locust, Locusta migratoria migratoria, oviposition sites in the Amudarya River delta, Uzbekistan?ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2008Ramesh Sivanpillai Abstract Existing survey methods for assessing the Asian migratory locust, Locusta migratoria migratoria L. (Orthoptera: Acrididae), infestation risk in the Amudarya River delta, Uzbekistan, are largely constrained by economic resources and site accessibility. The surveys are restricted to a few easily accessible areas, which leads to a misinterpretation of the threat of locust infestation. This often results in indiscriminate blanket treatments of vast areas of wetlands with broad-spectrum insecticides, which may adversely impact non-target fauna and flora. In order to minimize the bias during surveys, one approach would be to allocate the sampling locations based on the distribution of the primary food and shelter plant of the locusts, the common reed, Phragmites australis (Cav.) Trin. ex Steud (Poaceae). In this study, we evaluated the utility of satellite-based remotely sensed data (Landsat TM) acquired in August 2006 to characterize reed distribution in the delta and identify potential locust oviposition sites. The overall accuracy of the Landsat data to map land cover classes in the delta was 84%. The Landsat TM data identified 90% of the reeds, but it was less useful in identifying areas where other vegetations (shrubs and grasses) were mixed with reeds. During the following summer field survey in June 2007, we identified 37 sites that were infested with early-instar locusts. The low migration capacity of young nymphs in dense reed vegetation allowed us to presume that these sites were used for oviposition in the previous summer. Twenty-eight (74%) of these 37 sites had reeds in the previous year. Results from these studies demonstrate that reed distribution maps derived from satellite data could be used for targeting locust egg-pod survey locations, in order to minimize sampling bias while predicting locust infestation risks for the following season. [source] Protection of lodgepole pines from mass attack by mountain pine beetle, Dendroctonus ponderosae, with nonhost angiosperm volatiles and verbenoneENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2001D.P.W. Huber Abstract A number of angiosperm nonhost volatiles (NHVs) and green leaf volatiles (GLVs) were tested alone and as supplements to the antiaggregation pheromone, verbenone, for their ability to disrupt attack by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), on lodgepole pine, Pinus contorta Dougl. ex Loud. var. latifolia Engel. Preliminary experiments led to a refined NHV blend [benzyl alcohol, guaiacol, benzaldehyde, nonanal, salicylaldehyde, and conophthorin] and a refined GLV blend [(Z)-3-hexen-1-ol and (E)-2-hexen-1-ol]. In a 20-replicate experiment, NHV and GLV groups both singly, and verbenone alone, significantly reduced MPB mass attack on pheromone-baited trees and on trees within 5 m of the pheromone-baited trees. Both blends in combination with verbenone reduced the number of mass attacked, baited trees to three out of 20 compared to 20 out of 20 of the baited controls. Each binary combination was also effective at reducing mass attack. In these experiments, all tested repellents were released from devices stapled to trees at the same point as the pheromone bait, suggesting that the repellency could have been to a point source, rather than to the whole tree. Therefore, in two further experiments bands of release devices were wrapped around the treated trees and the pheromone bait was removed from the treated trees. In one experiment, when the aggregation pheromone bait was suspended between pairs of trees treated with the NHV blend plus GLV blend plus verbenone, only three out of 25 treated pairs had mass attack on at least one member of the pair. In the other 60-replicate experiment, with no pheromone baits present, attack occurred on 13 untreated and 11 banded trees, all in the path of a large advancing infestation. However, the mean attack density on the banded trees was significantly reduced to a level below the 40 attacks m,2 of bark surface required to kill a healthy lodgepole pine. As a result of these experiments, operational trials are recommended. [source] First report of cottony-cushion scale (Icerya purchasi) on red berried mistletoe (Viscum cruciatum)ENTOMOLOGICAL RESEARCH, Issue 1 2009Diego RUBIALES Abstract Cottony-cushion scale (Icerya purchasi) infestation on red berried mistletoe (Viscum cruciatum) is reported for the first time. Mistletoe is a hemiparasitic plant that was parasitizing stems of olive trees; however, I. purchasi infested only the mistletoe and not the olive. Economic implications are discussed. [source] Graphium agamemnon Linnaeus (Lepidoptera: Papilionidae), a pest of soursop (Annona muricata Linnaeus), in Vietnam: Biology and a novel method of controlENTOMOLOGICAL RESEARCH, Issue 2 2008Nga Thi VU Abstract Few butterflies are pests of economic significance, but some may be locally destructive, such as the papilionid Graphium agamemnon Linnaeus, which is known to feed on the commercially important soursop (Annona muricata Linnaeus) in Vietnam. This paper documents the life history and ecology of G. agamemnon and investigates commonly used control measures in south-east Vietnam. A novel method of controlling G. agamemnon infestation is described. If soursop basal rootstock (Annona glabra Linnaeus) is encouraged to shoot during times of peak butterfly activity, ovipositing G. agamemnon females are preferentially attracted to the new growth where the resulting early stages may be easily detected and removed by hand. [source] The fig wax scale Ceroplastes rusci (Linnaeus) (Homoptera: Coccidae) in south-east Vietnam: Pest status, life history and biocontrol trials with Eublemma amabilis Moore (Lepidoptera: Noctuidae)ENTOMOLOGICAL RESEARCH, Issue 4 2006Nga Thi VU Abstract The fig wax scale Ceroplastes rusci (Linnaeus) is a serious pest of fruit trees in many countries. In the present study we investigated the extent of C. rusci infestation and the range of host species, particularly in fruit orchards, in south-east Vietnam. Captive populations of C. rusci were established to record life history parameters and to investigate the efficacy of an endemic predacious moth, Eublemma amabilis Moore, as a potential biocontrol agent. Heavy infestation of C. rusci (up to 100%) was recorded in soursop and other fruit orchards, and the culturally important Hoa Mai flower was also affected. Captive breeding trials found E. amabilis to be an efficient predator of C. rusci, but an unusual hyperactive trait in early instars of E. amabilis resulted in lower than expected survival rates. The implications of this trait in terms of the laboratory environment, augmentative release protocols and as a survival strategy are discussed. [source] Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of SugarcaneENTOMOLOGICAL RESEARCH, Issue 3 2005Abdul KHALIQ ABSTRACT Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval. [source] Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable FruitsENTOMOLOGICAL RESEARCH, Issue 2 2005Muhammad Ahsan KHAN ABSTRACT We investigated to minimize the dependency on the use of chemicals and thus develop safe and environmental friendly control program for the most perishable fruits i.e., apple,,ber', guava and mango. Our findings on the composition of fruit fly species reveal that Bactrocera dorsalis was dominant on apple (33.96% existence), Corpomya incompleta on,ber'(51.91% existence) and Bactrocera zonata on guava (49.62% existence) and mango (74.66% existence). The correlation between population and infestation percentage was non-significant in apple orchards, whereas positive and highly significant in between population and infestation, as well as on the cumulative basis in,ber', guava and mango orchards during 1998-1999. Hoeing, baiting and methyl eugenol were statistically equal resulting about 77% decrease in infestation. The maximum control of 91.68% was observed where all four-control operations including Dipterex® were integrated together. Weather factors, when computed together, had maximum effect on population fluctuation and infestation with rainfall contributing the major role. For guava fruits, the months of August (14.06A individuals/trap/day) and September (13.81A individuals/trap/day) were important, resulting in maximum infestation percentage of 10.76 to 14.74%, respectively. [source] Cecidophagy in adults of Demotina fasciculata (Coleoptera: Chrysomelidae) and its effect on the survival of Andricus moriokae (Hymenoptera: Cynipidae) inhabiting leaf galls on Quercus serrata (Fagaceae)ENTOMOLOGICAL SCIENCE, Issue 1 2010Takayoshi KATSUDA Abstract Females of Demotina fasciculata (Coleoptera: Chrysomelidae) were found to prefer to feed on galls induced by Andricus moriokae (Hymenoptera: Cynipidae) rather than on leaves of its host plant, Quercus serrata (Fagaceae). This is the first record of cecidophagy by adult chrysomelid beetles. Demotina fasciculata did not infest healthy galls induced by another unidentified cynipid species on the same host trees, but did feed on galls inhabited by an inquiline species Synergus quercicola (Hymenoptera: Cynipidae), presumably because such galls remained on the host trees longer than healthy galls. Galls of A. moriokae were infested more severely than cynipid galls inhabited by the inquiline. Therefore, higher density and thicker gall wall in A. moriokae galls seem to make them more suitable targets for D. fasciculata to attack. Larval chambers of A. moriokae galls were stripped by the infestation of gall walls and readily dropped to the ground, resulting in 100% death of cynipid larvae due to desiccation, while 62.5% of pupae survived when they had developed to the late stadium before the fall of larval chambers. [source] Evaluation of eradication measures against Anoplophora chinensis in early stage infestations in EuropeEPPO BULLETIN, Issue 2 2010D. J. Van Der Gaag Eradication efforts are described at 5 sites where infestations of Anoplophora chinensis have been detected in Europe since 2003. The infestations were in France (declared eradicated in 2006), in Croatia, in Italy (Rome) and in the Netherlands (Westland and Boskoop). Each of these infestations was on or nearby a nursery or location where plants originating from Eastern Asia had (probably) been stocked or sold. Infested plants were all found within a distance of 30 m from the presumed source of infestation except in the Rome-infestation where infested plants, in total 40, were found within 500 m of the presumed source of infestation. The history of plant imports and local observations at 3 sites (France, Croatia and Westland in the Netherlands) suggests that larvae arrived in imported plants and adults emerged and laid eggs on plants in the surroundings between 1 and 5 years before the infestation was detected. It was not possible to make such an estimate for the Boskoop infestation in the Netherlands and the Rome infestation in Italy. [source] Parasitized Salamanders are Inferior Competitors for Territories and Food ResourcesETHOLOGY, Issue 4 2000Daria S. Maksimowich Parasites have been shown to impair the behaviour of their hosts, compromising the host's ability to exploit and compete for resources. We conducted two experiments to determine whether infestation with an ectoparasitic mite (Hannemania eltoni) was associated with changes in aggressive and foraging behaviour in the Ozark zigzag salamander, Plethodon angusticlavius. In a first experiment, male salamanders with high parasite loads were less aggressive overall than males with low parasite loads during territorial disputes. In addition, males with high parasite loads were more aggressive toward opponents with high parasite loads (symmetric contests) than toward opponents with low parasite loads (asymmetric contests). In contrast, males with low parasite loads did not adjust their level of aggression according to the parasite load of the opponent. In a second experiment, foraging behaviour of females was tested in response to ,familiar' (Drosophila) prey and ,novel' (termite) prey. Latency to first capture was significantly longer for parasitized than non-parasitized females when tested with ,familiar' prey, but not for ,novel' prey. Our results suggest that parasite-mediated effects may have profound influences on individual fitness in nature. [source] Analysis of the distribution of Phytophthora cinnamomi in soil at a disease site in Western Australia using nested PCRFOREST PATHOLOGY, Issue 2 2009N. Williams Summary The oomycete plant pathogen Phytophthora cinnamomi has infected a very large area of native vegetation in the south western corner of Australia. An important aspect of effective disease management depends on being able to accurately map areas of infestation. For this purpose, we have developed a nested polymerase chain reaction (PCR) protocol for the detection of P. cinnamomi in soil. The test uses two sets of primers developed from the rRNA ITS sequences of P. cinnamomi and can detect as little as 1 pg DNA. The degree of sensitivity was reduced with DNA extracted from soil although this depended on the type of soil. Soils with a high organic content, such as eucalypt forest soil and potting mix were more inhibitory than sandy soils. Inhibition by soil DNA could be reduced by the addition of bovine serum albumin and formamide to the reaction. Taq DNA polymerase was very sensitive to inhibitors compared with Tth+ or TaqF1*. In comparison with baiting (0,10% positive samples), nested PCR proved to be a very much more efficient (90,100% positive samples) method for the detection of P. cinnamomi in soil. [source] Developmental, metabolic and immunological costs of flea infestation in the common voleFUNCTIONAL ECOLOGY, Issue 6 2008Godefroy Devevey Summary 1Parasites use resources from their hosts, which can indirectly affect a number of host functions because of trade-offs in resource allocation. In order to get a comprehensive view of the costs imposed by blood sucking parasites to their hosts, it is important to monitor multiple components of the development and physiology of parasitized hosts over long time periods. 2The effect of infestation by fleas on body mass, body length growth, haematocrit, resistance to oxidative stress, resting metabolic rate and humoral immune response were experimentally evaluated. During a 3-month period, male common voles, Microtus arvalis, were either parasitized by rat fleas (Nosopsyllus fasciatus), which are naturally occurring generalist ectoparasites of voles, or reared without fleas. Then voles were challenged twice by injecting Keyhole Limpet Haemocyanin (KLH) to assess whether the presence of fleas affects the ability of voles to produce antibodies against a novel antigen. During the immune challenge we measured the evolution of body mass, haematocrit, resistance to oxidative stress and antibody production. 3Flea infestation negatively influenced the growth of voles. Moreover, parasitized voles had reduced haematocrit, higher resting metabolic rate and lower production of antibodies against the KLH. Resistance to oxidative stress was not influenced by the presence of fleas. 4During the immune challenge with KLH, body mass decreased in both groups, while the resistance to oxidative stress remained stable. In contrast, the haematocrit decreased only in parasitized voles. 5Our experiment shows that infestation by a haematophageous parasite negatively affects multiple traits like growth, energy consumption and immune response. Fleas may severely reduce the survival probability and reproductive success of their host in natural conditions. [source] Effect of tick parasitism on the health status of a passerine birdFUNCTIONAL ECOLOGY, Issue 6 2008D. J. A. Heylen Summary 1Little information is available on the ecological interactions between ticks and their hosts under natural conditions, and particularly so for avian hosts. To understand this host,parasite interaction it is necessary to assess the physiological harm ticks can do to their host. 2We combined observational and experimental (field and laboratory) data to examine the effects of a common tick species with major economic importance, the sheep tick (Ixodes ricinus), on the health status of a common passerine bird, the great tit (Parus major). 3In the laboratory experiment a parallel group design was carried out in which the birds of the experimental group were infested with 3,10 nymphs, whereas the birds of the control group were kept free of ticks and received a sham treatment. Both groups were stratified according to age and sex. Health parameters were measured the day before and 3 days after infestation or sham treatment: haematocrit level, erythrocyte sedimentation rate, leucocyte concentration and general body condition (body mass corrected for body size). 4No effects of age were observed on any of the health parameters. The decrease in haematocrit level in the experimental group was significantly greater than in the control group. Moreover, infested males suffered more blood depletion than infested females. The increase in sedimentation rate was greater in the experimental group than in the control group. Surprisingly, no treatment effects were found on leucocyte concentrations, which may indicate immunoregulation by the ticks on components of the birds' cellular immune response. Also no difference in general body condition between the treatment groups was found. None of the infested birds died during infestation. 5Lower haematocrit levels in infested birds, but unaffected leucocyte concentrations and general body condition are confirmed by field data (experimental and observational) of adult birds during breeding season. 6Neither haematocrit level nor general body condition was associated with parasite intensity among infested birds, suggesting that immature Ixodes ricinus are not resource limited at high natural densities. Still, the measurable direct harm caused by sheep tick infestations calls for further study on its importance for the evolutionary ecology of passerine hosts. [source] Effects of parasite specificity and previous infestation of hosts on the feeding and reproductive success of rodent-infesting fleasFUNCTIONAL ECOLOGY, Issue 3 2008I. S. Khokhlova Summary 1We examined whether identity of the rodent host and previous infestation of the host affect feeding and reproduction of fleas. We predicted that feeding and reproductive success of fleas would be higher when feeding on (i) a typical host than on an atypical host; and (ii) a pristine host than on a host previously exposed to parasitism. We also predicted that the negative effect of previous infestation would not be manifested in a host-specific flea feeding on its typical host. 2To test these predictions, we measured blood meal size, egg production and latency of oviposition in host-specific Parapulex chephrenis and host-opportunistic Xenopsylla ramesis during seven daily feedings on the Egyptian spiny mouse Acomys cahirinus (typical host of the former) and Wagner's gerbil Dipodillus dasyurus (typical host of the latter). 3Blood meal size in P. chephrenis did not depend on either host species or previous host infestation with fleas. However, when this flea fed on D. dasyurus as opposed to A. cahirinus, blood meal size increased to the end of 7-day period. Xenopsylla ramesis took larger blood meals (i) during the first feeding; (ii) from D. dasyurus than from A. cahirinus; and (iii) from pristine than from previously infested D. dasyurus, but the blood meals taken from pristine and previously infested A. cahirinus were similar. 4Egg production of P. chephrenis was significantly higher and oviposition started earlier when it fed on A. cahirinus; this was true for X. ramesis when it fed on D. dasyurus. Surprisingly, P. chephrenis laid more eggs and started oviposition earlier when it fed on previously infested rodents. However, egg production in X. ramesis and start of oviposition were similar in pristine and previously infested hosts. 5These results suggest that the response of a parasite to acquired immunity of a host may depend on the host species, level of parasite host specificity as well as the degree of ,tightness' of a particular parasite,host association. [source] | |||||||||||||||||||||||||||||||||||||||||||