scholarly journals Positive and negative effects of phoretic mites on the reproductive output of an invasive bark beetle

2010 ◽  
Vol 58 (3) ◽  
pp. 198 ◽  
Author(s):  
Lisa K. Hodgkin ◽  
Mark A. Elgar ◽  
Matthew R. E. Symonds
Keyword(s):  
Beneficial Effect ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Reproductive Output ◽  
Experimental Manipulation ◽  
Life Stages ◽  
Negative Effects ◽  
Ips Grandicollis ◽  
Single Host ◽  
Multiple Species

When multiple species coexist upon a single host, their combined effect on the host can be unpredictable. We explored the effect of phoretic mites on the reproductive output of the five-spined bark beetle, Ips grandicollis. Using correlative approaches and experimental manipulation of mite numbers we examined how mite load affected the number, size and condition of bark beetle offspring produced. We found that mites have both negative and positive consequences on different aspects of bark beetle reproduction. Females from which mites were removed were more fecund and produced larger offspring than females with mites, implying a cost of mite loads. However, when mites were present on females, those bearing the highest mite loads produced offspring that were larger and in better condition, indicating a beneficial effect of mites. These data suggest that phoretic interactions between mites and bark beetles differ over the course of the host’s lifespan, with either the mites interacting in different ways with different life stages of the host (parasitic on adult, mutualistic with larvae), and/or the beetles being host to different mite assemblages over their lifetime.

scholarly journals Ips sexdentatus Mass-Trapping: Mitigation of Its Negative Effects on Saproxylic Beetles Larger Than the Target

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 175
Author(s):  
Matteo Bracalini ◽  
Francesco Croci ◽  
Emanuele Ciardi ◽  
Giulio Mannucci ◽  
Emanuele Papucci ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Natural Enemies ◽  
Bark Beetles ◽  
Mass Trapping ◽  
Beetle Species ◽  
Negative Effects ◽  
Thanasimus Formicarius ◽  
Mesh Screen ◽  
Ips Sexdentatus ◽  
Average Size

Research Highlights: We investigated the negative effects of bark beetle mass trapping, especially non-target catches among the target’s natural enemies. Slot traps modified with mesh screen and escape windows were tested to improve their selectiveness. Background and Objectives: Two of the main natural enemies of bark beetles, Thanasimus formicarius (L.) and Temnoscheila caerulea (Olivier), are frequently trapped in high numbers in Ips sexdentatus (Böerner) pheromone traps, along with other saproxylic insects; this may lead to much larger pest populations in the successive 4–20 beetle generations. From 2016–2019, during I. sexdentatus mass-trapping in a pine forest of Tuscany (Italy), non-target catches were tallied. Trap modifications were evaluated to mitigate non-target catches, especially those concerning bark beetles’ natural enemies. Materials and Methods: A total of 25 bark-beetle slot traps were placed about 75 m apart in a pine stand infested by I. sexdentatus. Traps were baited with I. sexdentatus aggregation pheromone, whose main components are ipsenol, ipsdienol, and 2-methyl-3-buten-2-ol. Catches were collected every 10 days from March to December. In 2019, 13 traps were modified by applying a 6-mm mesh screen on top of the collection container and by providing three 60 mm × 8 mm escape windows immediately above the screen. These “modified traps” and their captures were considered separately from the 12 remaining “standard traps.” All bark beetle species were recorded, as well as all beetle species > 8 mm. Results: Overall, target catches amounted for <10% of the total beetle catches. The most-collected species was the bark beetle Orthotomicus erosus Wollaston. Trap modification allowed the escape of larger species, resulting in the reduction of the average size of caught specimens. Even though non-target catches among predators were still high, the proportion of major predators (T. formicarius and T. caerulea) to bark beetles showed a statistically significant reduction of predator catches in modified traps, an encouraging outcome. Conclusions: Trap modifications may mitigate the problem of non-target catches during mass trapping, especially reducing catches of beetle species larger than the target. However, the key is to schedule mass trapping only during those seasons when the target adults are more active than the main predator adults, thus limiting their catches and, consequently, the negative effects on pest management and biodiversity.

scholarly journals Environment and Local Substrate Availability Effects on Harem Formation in a Polygynous Bark Beetle

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 98 ◽  
Author(s):  
Melissa J. Griffin ◽  
Matthew R. E. Symonds
Keyword(s):  
Population Density ◽  
Bark Beetle ◽  
Substrate Availability ◽  
Pine Plantation ◽  
Single Male ◽  
Animal Groups ◽  
Ips Grandicollis ◽  
Surrounding Environment ◽  
External Conditions ◽  
Species Groups

Many forms of polygyny are observed across different animal groups. In some species, groups of females may remain with a single male for breeding, often referred to as “harem polygyny”. The environment and the amount of habitat available for feeding, mating and oviposition may have an effect on the formation of harems. We aimed to determine how the surrounding environment (a harvested or unharvested pine plantation) and availability of local substrate affect the harems of the bark beetle, Ips grandicollis (Coleoptera: Curculionidae: Scolytinae). In a harvested pine plantation with large amounts of available habitat, the population density of these beetles is much higher than in unharvested plantations. We found the number of females per male to be significantly greater in the harvested plantation than the unharvested one. Additionally, the amount of substrate available in the immediate local vicinity (the number of logs in replicate piles) also influences the number of beetles attracted to a log and size of individual harems. We also examined how females were distributing themselves in their galleries around the males’ nuptial chamber, as previous work has demonstrated the potential for competition between neighbouring females and their offspring. Females do not perform clumping, suggesting some avoidance when females make their galleries, but they also do not distribute themselves evenly. Female distribution around the male’s nuptial chamber appears to be random, and not influenced by other females or external conditions.

scholarly journals Drivers of Spruce Bark Beetle (Ips typographus) Infestations on Downed Trees after Severe Windthrow

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Ips Typographus ◽  
Wind Damage ◽  
Stem Length ◽  
Local Conditions ◽  
Spruce Bark Beetle ◽  
Management Actions ◽  
Spruce Bark

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.

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.

ATTRACTION OF HYLOBIUS PALES (HERBST) (COLEOPTERA: CURCULIONIDAE) TO PHEROMONES OF BARK BEETLES (COLEOPTERA: SCOLYTIDAE)

1990 ◽  
Vol 122 (3) ◽  
pp. 423-427 ◽  
Author(s):  
Thomas W. Phillips
Keyword(s):  
Field Experiment ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Suitable Host ◽  
Male And Female ◽  
Pine Weevil ◽  
Ips Calligraphus ◽  
Hylobius Pales ◽  
Host Resource

AbstractResults of a field experiment indicate that adults of the pine weevil Hylobius pales (Herbst) respond to pheromones of bark beetles. Each sex of H. pales was more attracted to traps baited with the combination of a pine bolt infested with male Ips calligraphus Germar plus the synthetic Dendroctonus Erichson pheromones frontalin and exo-brevicomin, than to traps baited with pine bolts alone. The combined numbers of male and female H. pales caught in traps baited only with Ips calligraphus-infested bolts were significantly greater than numbers caught in traps baited with uninfested control bolts. The attraction of H. pales to bark beetle pheromones may represent a kairomonal response in which weevils exploit semiochemicals from other species that signify a suitable host resource.

Impacts of European spruce bark beetle infestations on Norway spruce BVOC emissions

2021 ◽  
Author(s):  
Erica Jaakkola ◽  
Anna Maria Jönsson ◽  
Per-Ola Olsson ◽  
Maj-Lena Linderson ◽  
Thomas Holst
Keyword(s):  
Climate Change ◽  
Drought Stress ◽  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Atmospheric Environment ◽  
Strong Increase ◽  
Healthy Tree ◽  
Spruce Bark Beetle ◽  
Spruce Bark

&lt;p&gt;Tree killing by spruce bark beetles (&lt;em&gt;Ips typographus&lt;/em&gt;) is one of the main disturbances to Norway spruce (&lt;em&gt;Picea abies&lt;/em&gt;) forests in Europe and the risk of outbreaks is amplified by climate change with effects such as increased risk of storm felling, tree drought stress and an additional generation of spruce bark beetles per year&lt;sup&gt;[1]&lt;/sup&gt;. The warm and dry&amp;#160;summer of&amp;#160;2018 triggered large outbreaks in Sweden, the increased outbreaks are still ongoing and affected&amp;#160;about 8 million m&lt;sup&gt;3&lt;/sup&gt;&amp;#160;forest&amp;#160;in 2020&lt;sup&gt;[2]&lt;/sup&gt;. This is the so&amp;#160;far highest record of trees killed by the spruce bark beetle in a single year in Sweden&lt;sup&gt;[2]&lt;/sup&gt;. In&amp;#160;1990-2010,&amp;#160;the spruce bark beetle killed on&amp;#160;average&amp;#160;150 000 m&lt;sup&gt;3&lt;/sup&gt;&amp;#160;forest per year in southern Sweden&lt;sup&gt;[3]&lt;/sup&gt;. Bark beetles normally seek and attack Norway spruces with lowered defense, i.e. trees that are wind-felled or experience prolonged drought stress&lt;sup&gt;[4]&lt;/sup&gt;. However, as the number of bark beetle outbreaks increase, the risk of attacks on healthy trees also increase&lt;sup&gt;[5]&lt;/sup&gt;. This causes a higher threat to forest industry, and lowers the possibilities to mitigate climate change in terms of potential decreases in carbon uptake if the forests die&lt;sup&gt;[4,5]&lt;/sup&gt;. Norway spruce trees normally defend themselves by drenching the beetles in resin&lt;sup&gt;[6]&lt;/sup&gt;. The resin in turn contains different biogenic volatile organic compounds (BVOCs), which can vary if the spruce is attacked by bark beetles or not&lt;sup&gt; [4,6]&lt;/sup&gt;. The most abundant group of terpenoids (isoprene, monoterpenes and sesquiterpenes), is most commonly emitted from conifers, such as Norway spruce&lt;sup&gt;[7,8]&lt;/sup&gt;. The aim of this study was to enable a better understanding of the direct defense mechanisms of spruce trees by&amp;#160;quantifying BVOC emissions and its composition&amp;#160;from individual&amp;#160;trees under attack&lt;/p&gt;&lt;p&gt;To analyze the bark beetles&amp;#8217; impact on Norway spruce trees a method was developed using tree trunk chambers and adsorbent tubes. This enables direct measurements of the production of BVOCs from individual trees. Three different sites in Sweden, with different environmental conditions were used for the study and samples were collected throughout the growing season of 2019. After sampling, the tubes were analyzed in a lab using automated thermal desorption coupled to a gas chromatograph and a mass spectrometer to identify BVOC species and their quantity.&lt;/p&gt;&lt;p&gt;The preliminary results show a strong increase in BVOC emissions from a healthy tree that became infested during the data collection. The finalized results expect to enable better understanding of how spruce trees are affected by insect stress from bark beetles, and if bark beetle infestation will potentially result in increased carbon emission in the form of BVOCs.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;[1] J&amp;#246;nsson et al. (2012). Agricultural and Forest Meteorology 166: 188&amp;#8211;200&lt;br&gt;[2] Skogsstyrelsen, (2020). https://via.tt.se/pressmeddelande/miljontals-granar-dodades-av-granbarkborren-2020?publisherId=415163&amp;releaseId=3288473&lt;br&gt;[3] Marini et al. (2017). Ecography, 40(12), 1426&amp;#8211;1435.&lt;br&gt;[4] Raffa (1991). Photochemical induction by herbivores. pp. 245-276&lt;strong&gt;&lt;br&gt;&lt;/strong&gt;[5] Seidl, et al. (2014). Nature Climate Change,&amp;#160;4(9), 806-810. &lt;br&gt;[6] Ghimire, et al. (2016).&amp;#160;Atmospheric Environment,&amp;#160;126, 145-152.&lt;br&gt;[7] Niinemets, U. and Monson, R. (2013). ISBN 978-94-007-6606-8&lt;br&gt;[8] Kesselmeier, J. and Staudt, M. (1999). Journal of Atmospheric Chemistry, 33(1), pp.23-88&lt;/p&gt;

Failure of ovarian development in the Douglas-fir bark beetle, Dendroctonus pseudotsugae; an analysis of gut proteases and female-specific proteins

1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota
Keyword(s):  
High Activity ◽  
Bark Beetle ◽  
Methyl Ether ◽  
Bark Beetles ◽  
Ovarian Development ◽  
Proteolytic Enzymes ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Specific Proteins ◽  
Female Specific

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.

scholarly journals Effects of forest roads on Ips sexdentatus infestation in black pine forest

2018 ◽  
Vol 6 (7) ◽  
pp. 828
Author(s):  
Gonca Ece Özcan ◽  
Korhan Enez ◽  
Burak Arıcak
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Forest Ecosystems ◽  
Significant Risk ◽  
Pine Forests ◽  
Slope Aspect ◽  
Black Pine ◽  
Forest Roads ◽  
Forest Road ◽  
Ips Sexdentatus

Forest roads are important transportation equipment through forested areas in the rugged, mountainous terrain of northern Turkey. Forest roads harm forest ecosystems due to both the manner in which they are established and how they are used afterwards. Damage to trees that occur during road construction through forests stresses trees, which facilitates outbreaks of bark beetle populations. Bark beetles are significant risk to the health and productivity of Turkish pine forests and to pine forests worldwide. In particular, Ips sexdentatus (Boerner) (Coleoptera, Curculionidae, Scolytinae) is a particularly destructive species of bark beetle in Turkish forests. Their damage to coniferous trees threatens the sustainability of the forest ecosystems. This study primarily aims to assess the intensity of damage that I. sexdentatus inflicts on Pinus nigra J.F.Arnold stands relative to several parameters: the distance to the nearest forest road, aspect (shady - sunny), slope (0–15% or >15%), and other stand characteristics. In this study, we show how damage by an I. sexdentatus infestation in pure black pine stands varies with distance to forest roads and in situ edaphic factors. We sampled 45 plots (400 m2 each), slope, aspect and distances to the nearest forest road was determined using ArcGIS software and the region’s road network overlays. Results showed that trees located within 100 m from the nearest forest road were the most severely damaged ones. The intensity of I. sexdentatus damage was about 16% in a hectare. Trees that were in 16–20 cm diameter class were damaged more often. I. sexdentatus damage did not show any significant correlation with the slope, aspect or degree of canopy closure.

scholarly journals Bark Beetle Population Dynamics in the Anthropocene: Challenges and Solutions

2018 ◽  
Author(s):  
Peter H. W. Biedermann ◽  
Jean-Claude Grégoire ◽  
Axel Gruppe ◽  
Jonas Hagge ◽  
Almuth Hammerbacher ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Bark Beetle ◽  
Collaborative Research ◽  
Bark Beetles ◽  
Large Scale ◽  
Ips Typographus ◽  
Ecological Framework ◽  
Beetle Population ◽  
Spruce Bark ◽  
Important Pest

Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. Yet&nbsp; despite &gt;200 years of research, the drivers of population eruptions or crashes are still not fully understood, precluding reliable predictions of the effects of global change on beetle population dynamics and impacts on ecosystems and humans.&nbsp; We critically analyze potential biotic and abiotic drivers of population dynamics of the European spruce bark beetle (Ips typographus) and present a novel ecological framework that integrates the multiple drivers governing this bark beetle system. We call for large-scale collaborative research efforts to improve our understanding of the population dynamics of this important pest; an approach that might serve as a blueprint for other eruptive forest insects.

scholarly journals Novel Antibiofilm Non-Biocidal Strategies

2021 ◽  
pp. 117-136
Author(s):  
Francesca Cappitelli ◽  
Federica Villa
Keyword(s):  
Control Strategies ◽  
Model Systems ◽  
Negative Effects ◽  
Alternative Strategies ◽  
Biofilm Model ◽  
Biocidal Products ◽  
Multiple Species ◽  
Cultural Heritage Objects ◽  
And Control ◽  
By Products

AbstractSubaerial biofilm (SAB) formation on cultural heritage objects is often considered an undesirable process in which microorganisms and their by-products, e.g., enzymes and pigments, cause damage or alteration to a surface. Since biofilms are widespread phenomena, there has been a high demand for preventive and control strategies that resist their formation or reduce their negative effects once formed. Up to date, the main strategy to control biofilms has been the use of biocides. Because of their intrinsic properties, biocidal products can pose risks to humans, animals, and the environment. In this chapter, the authors call “green” only those alternative strategies to biocides able to prevent/control biofilms but that do not kill microorganisms, i.e., irrespective of the use of natural compounds. Here, we describe some of the methods that are most commonly used to test the effectiveness of antibiofilm compounds with multiple-species biofilm model systems. A unified terminology and well described protocols and guidelines are still required to compare and test the effectiveness of traditional or novel compounds against biofilms retrieved on heritage surfaces.

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