EFFECTS OF CROWDING ON SUPLHURETYLENCHUS SPP. (NEMATODA: ALLANTONEMATIDAE) IN THE HAEMOCOEL OF THEIR BARK BEETLE HOSTS (COLEOPTERA: SCOLYTIDAE)

1989 ◽  
Vol 121 (9) ◽  
pp. 821-822
Author(s):  
Marek Tomalak ◽  
Harold E. Welch ◽  
Terry D. Galloway
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Biological Control Agents ◽  
Infection Rates ◽  
Intensity Of Infection ◽  
Nematode Parasites ◽  
Host Parasite Interactions ◽  
Host Parasite ◽  
The Relationship ◽  
Growth And Reproduction

Nematode parasites of bark beetles are taxonomically diverse, and may, in some cases, cause serious pathological and behavioural changes in their hosts (Kaya 1984). Their potential as biological control agents has long been recognized, but to date there is a shortage of elementary information on host-parasite interactions. Though the effects of superparasitism and subsequent crowding on the parasite have been studied for some mermithids (Petersen 1972) and steinernematids (Sandner and Stanuszek 1971), no such observations have been reported for bark beetle parasites. During a survey of nematode parasites of bark beetles in Manitoba, we encountered two examples where nematodes were detrimentally affected at the higher infection rates observed. It was our objective, therefore, to examine the relationship between intensity of infection, and impact on growth and reproduction of the parasites.

INFESTATION OF CERATOCYSTIS WAGENERI-INFECTED PONDEROSA PINES BY BARK BEETLES (COLEOPTERA: SCOLYTIDAE) IN THE CENTRAL SIERRA NEVADA

1980 ◽  
Vol 112 (7) ◽  
pp. 725-730 ◽  
Author(s):  
D. J. Goheen ◽  
F. W. Cobb
Keyword(s):  
Sierra Nevada ◽  
Bark Beetle ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Dendroctonus Brevicomis ◽  
Disease Category ◽  
The Relationship ◽  
Periodic Examination ◽  
Apparently Healthy

AbstractThe relationship between bark beetle infestation of ponderosa pine and severity of infection by Ceratocystis wageneri was investigated by closely monitoring 256 trees (136 apparently healthy, 60 moderately diseased, and 60 severely diseased at initiation of study) for beetle infestation from summer 1972 to fall 1975. Disease ratings were updated by periodic examination, and some trees changed disease category during the study. Ninety trees were infested by Dendroctonus brevicomis, D. ponderosae, or both, five by buprestids alone, and one tree died from effects of the pathogen alone. Sixty-two of the beetle-infested trees were severely diseased at time of infestation, 25 were moderately diseased, and only three were apparently healthy. Thus, the results showed that bark beetles were much more likely to infest infected than healthy trees. Among diseased trees, those with advanced infections were most likely to be infested. There was evidence that buprestids (especially Melanophila spp.) and possibly Ips spp. attacked diseased trees prior to Dendroctonus spp. infestation.

scholarly journals The Impacts of Calamity Logging on the Development of Spruce Wood Prices in Czech Forestry

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 283 ◽  
Author(s):  
Daniel Toth ◽  
Mansoor Maitah ◽  
Kamil Maitah ◽  
Veronika Jarolínová
Keyword(s):  
Czech Republic ◽  
Bark Beetle ◽  
Bark Beetles ◽  
The Czech Republic ◽  
Wood Harvesting ◽  
Spruce Bark ◽  
Spruce Wood ◽  
Forestry Sector ◽  
Socio Economic Impact ◽  
The Relationship

Currently, the decline in spruce wood prices is a serious problem for the forestry sector in the Czech Republic. We estimate that the fall in wood prices in European markets causes losses not only to the forestry companies producing, harvesting, and processing the wood, but also to the workers in the sector. These losses are mainly caused by a combination of several natural factors: drought, climate change, and the effects of bark beetles. In particular, spruce bark beetles cause the greatest damage. Due to this bark beetle calamity, unplanned logging has increased. In 2019, these damages have culminated. Almost 100 million m3 of wood has been harvested over the last decade due to the bark beetle and more than half of this volume has been mined in the last four years. Therefore, the losses in the forestry sector are around EUR 1.12 billion. The aim of this study is an analysis of the relationship between the volume of incidental logging and the decline in the price of spruce wood. These results show the strong correlation between the measure of unplanned wood harvesting and the decrease in wood prices, as well as an estimate of price development if the upward trend of incidental mining continues. The average price of wood in the Czech Republic could thus reach a historical minimum of EUR 79.39 per m3 of spruce and category SM/JE II (spruce/fir). In addition, the decline in wood prices will be reflected in the management of forestry and timber businesses, including stagnant wages for forestry workers. The socio-economic impact of the bark beetle calamity is high and is most affected by the decline in spruce timber prices.

Numerical and functional responses of intestinal helminths in three rajid skates: evidence for competition between parasites?

Parasitology ◽  
2012 ◽  
Vol 139 (13) ◽  
pp. 1784-1793 ◽  
Author(s):  
HASEEB S. RANDHAWA
Keyword(s):  
Linear Models ◽  
Niche Breadth ◽  
Specific Interactions ◽  
Intestinal Helminths ◽  
Functional Responses ◽  
Intensity Of Infection ◽  
Host Parasite Interactions ◽  
Niche Shifts ◽  
Host Parasite ◽  
Number Of Individuals

SUMMARYHost-parasite interactions generally involve communities of parasites. Within these communities, species will co-exist and/or interact with one another in a manner either benefiting the species involved or to the detriment of one or more of the species. At the level of helminth infracommunities, evidence for intra- and inter-specific competition includes numerical responses, i.e. those regulating helminth intensity of infection, and functional responses, i.e. where the presence of competitors modifies the realised niche of infrapopulations. The objectives of this study are to assess the numerical and functional responses of helminths in infracommunities from 3 rajid skates using general linear models. Despite a lack of numerical responses, functional responses to intra- and inter-specific interactions were observed. A positive correlation between the number of individuals in an infrapopulation and its niche breadth (functional response) was observed for the tapewormsPseudanthobothriumspp. andEcheneibothriumspp., in all their respective hosts, and for the nematodePseudanisakissp. in the little skate. Evidence for inter-specific competition includes niche shifts inPseudanthobothrium purtoni(exlittle skate) andPseudanisakissp. (exthorny skate) in the presence ofPseudanisakissp. and the tapewormGrillotiasp., respectively. These results are consistent with other studies in providing evidence for competition between helminths of skates.

scholarly journals Molecular Evidence that Lysiphlebia japonica Regulates the Development and Physiological Metabolism of Aphis gossypii

2020 ◽  
Vol 21 (13) ◽  
pp. 4610
Author(s):  
Xueke Gao ◽  
Hui Xue ◽  
Junyu Luo ◽  
Jichao Ji ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Aphis Gossypii ◽  
The Body ◽  
Molecular Evidence ◽  
Functional Categories ◽  
Host Parasite Interactions ◽  
Physiological Metabolism ◽  
Major Pest ◽  
Host Parasite ◽  
The Relationship ◽  
Insight Into

Lysiphlebia japonica Ashmead (Hymenoptera, Braconidae) is an endophagous parasitoid and Aphis gossypii Glover (Hemiptera, Aphididae) is a major pest in cotton. The relationship between insect host-parasitoids and their hosts involves complex physiological, biochemical and genetic interactions. This study examines changes in the development and physiological metabolism of A. gossypii regulated by L. japonica. Our results demonstrated that both the body length and width increased compared to non-parasitized aphids. We detected significantly increases in the developmental period as well as severe reproductive castration following parasitization by L. japonica. We then used proteomics to characterize these biological changes, and when combined with transcriptomes, this analysis demonstrated that the differential expression of mRNA (up or downregulation) captured a maximum of 48.7% of the variations of protein expression. We assigned these proteins to functional categories that included immunity, energy metabolism and transport, lipid metabolism, and reproduction. We then verified the contents of glycogen and 6-phosphate glucose, which demonstrated that these important energy sources were significantly altered following parasitization. These results uncover the effects on A. gossypii following parasitization by L. japonica, additional insight into the mechanisms behind insect-insect parasitism, and a better understanding of host-parasite interactions.

scholarly journals Alternate patterns of temperature variation bring about very different disease outcomes at different mean temperatures

2021 ◽  
Author(s):  
Charlotte Kunze ◽  
Pepijn Luijckx ◽  
Andrew L. Jackson ◽  
Ian Donohui
Keyword(s):  
Life History Traits ◽  
Infection Rates ◽  
Temperature Dependent ◽  
Disease Outcomes ◽  
Host Parasite Interactions ◽  
Temperature Regimes ◽  
Order Of Magnitude ◽  
Changing Patterns ◽  
Host Parasite ◽  
Heat Events

The dynamics of host-parasite interactions are highly temperature-dependent and may be modified by increasing frequency and intensity of climate-driven heat events. Here, we show that altered patterns of temperature variance lead to an almost order-of-magnitude shift in thermal performance of host and pathogen life history traits over and above the effects of mean temperature and, moreover, that different temperature regimes affect these traits differently. We found that diurnal fluctuations of ±3°C lowered infection rates and reduced spore burden compared to constant temperatures in our focal host Daphnia magna exposed to the microsporidium parasite Ordospora colligata. In contrast, a three-day heatwave (+6°C) did not affect infection rates, but increased spore burden (relative to constant temperatures with the same mean) at 16°C, while reducing burden at higher temperatures. We conclude that changing patterns of climate variation, superimposed on shifts in mean temperatures due to global warming, may have profound and unanticipated effects on disease dynamics.

scholarly journals The compound topology of a continent-wide interaction network explained by an integrative hypothesis of specialization

2017 ◽  
Author(s):  
Gabriel Moreira Felix ◽  
Rafael Barros Pereira Pinheiro ◽  
Robert Poulin ◽  
Boris R. Krasnov ◽  
Marco Aurelio Ribeiro de Mello
Keyword(s):  
Interaction Network ◽  
Interaction Networks ◽  
Resource Exploitation ◽  
Ecological Specialization ◽  
Large Dataset ◽  
Host Parasite Interactions ◽  
And Performance ◽  
Host Parasite ◽  
The Relationship ◽  
Shed Light

ABSTRACTIs there a prevalent pattern among interaction networks: nestedness or modularity? Must consumers always trade-off generalism for average performance in resource exploitation? These two questions have been addressed in various systems, with contradictory results. A recent integrative hypothesis combines both questions within a common theoretical framework, proposing that ecological specialization is structured by different prevailing processes in smaller and larger network units. This should produce both a compound interaction network, formed by internally nested modules, and a scale-dependence on the relationship between consumer performance and generalism. Here, we confirm both predictions in a large dataset on host-parasite interactions. We show that modules indeed constrain nestedness at the whole network level, and that the relationship between parasite generalism and performance on their hosts changed from negative at large to positive at small scales. Our results shed light on both debates, and provide some clues to their integration and solution.

A Synoptic List of the Parasites of Scolytidae (Coleoptera) in North America North of Mexico

1965 ◽  
Vol 97 (5) ◽  
pp. 449-492 ◽  
Author(s):  
Richard W. Bushing
Keyword(s):  
North America ◽  
American Literature ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Beetle Species ◽  
The North ◽  
Alphabetical List ◽  
Host Parasite ◽  
North America North ◽  
Seasonal History

AbstractA resumé of the North American literature concerned with hymenopterous parasites of bark beetles is presented. Morphology, seasonal history, host-tree selection, hyperparasitism, importation and colonization and their influence upon control of the host are briefly discussed.Parasites of a given host or hosts of a known parasite can easily be found in two different lists. Parasites are listed below in an alphabetical list of bark beetle species. Hosts, including some species other than bark beetles, are listed under a separate list of parasite families and genera. Host-parasite associations in each list are supported by a numerical reference to the literature cited.

The parasite Lernaeocera branchialis on caged cod: infection pattern is caused by differences in host susceptibility

Parasitology ◽  
2002 ◽  
Vol 124 (1) ◽  
pp. 69-76 ◽  
Author(s):  
D. A. LYSNE ◽  
A. SKORPING
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Host Susceptibility ◽  
Infection Rates ◽  
Time And Space ◽  
Parasite Abundance ◽  
Infection Pattern ◽  
Host Parasite Interactions ◽  
Host Parasite ◽  
Natural Situation

Variation in host susceptibility causes significant differences in infection rates between hosts living in a semi-natural situation. Such knowledge has implications for population dynamics and evolutionary models of host–parasite interactions as well as for estimations of parasite abundance. Infection rates by Lernaeocera branchialis (L.) were measured through time and space on caged Atlantic cod (Gadus morhua L.). One group of hosts, identified by their infection history, developed significantly higher infection rates than the others. These were fish which had been infected previously, but had lost their infection. Differences between groups were consistent through both time and space. Two types of cod seem to have been present in the caged population; a small group of inherently susceptible fish, which were infected, and reinfected if the parasite was lost, and another group of resistant hosts with a small chance of becoming infected.

scholarly journals An efficient photograph-based quantitative method for assessing castrating trematode parasites in bivalve molluscs

Parasitology ◽  
2020 ◽  
Vol 147 (12) ◽  
pp. 1375-1380 ◽  
Author(s):  
Joshua I. Brian ◽  
David C. Aldridge
Keyword(s):  
Reproductive Capacity ◽  
Bivalve Molluscs ◽  
Intensity Of Infection ◽  
Important Species ◽  
Gonad Tissue ◽  
Digenean Trematode ◽  
Host Parasite Interactions ◽  
Reproductive Response ◽  
Host Parasite ◽  
Trematode Parasites

AbstractParasitic castration of bivalves by trematodes is common, and may significantly reduce the reproductive capacity of ecologically important species. Understanding the intensity of infection is desirable, as it can indicate the time that has passed since infection, and influence the host's physiological and reproductive response. In addition, it is useful to know the developmental stage of the trematode, to understand trematode population trends and reproductive success. However, most existing methods (e.g. visually estimating the degree of infection) to assess intensity are approximate only and not reproducible. Here, we present a method to accurately quantify the percentage of bivalve gonad filled with digenean trematode tissue, based on small squashes of gonad tissue rapidly photographed under light microscopy. A maximum of 15 photographs is required to determine the percentage of the whole gonad occupied by trematodes with a minimum of 90% confidence, with smaller mussels requiring fewer. In addition, the stage of trematode infection can be assessed because full sporocysts, spent sporocysts and free cercariae are clearly distinguishable. Although variation exists in the distribution of trematodes in gonad tissue, and thus in the estimate of percentage of the gonad filled with trematodes, this method represents a marked improvement on current coarse assessments of infection which typically focus on binary presence/absence measures. This technique can be used to facilitate a more sophisticated understanding of host–parasite interactions in bivalves, and can inform the conservation and reproductive biology of environmentally crucial species.

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