Population dynamics of bark beetles, with special reference to Ips typographus: contributions of applied bark beetle studies to basic research in ecology and population biology

Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. Yet  despite >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.  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.

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Comparison of pathogens infection level in Ips typographus (Coleoptera: Curculionidae) beetles sampled in pheromone traps and at place of overwintering

Acta Parasitologica ◽

10.1515/ap-2015-0064 ◽

2015 ◽

Vol 60 (3) ◽

Cited By ~ 1

Author(s):

Karolina Lukášová ◽

Jaroslav Holuša

Keyword(s):

Population Dynamics ◽

Bark Beetle ◽

Bark Beetles ◽

Fat Body ◽

Ips Typographus ◽

Pheromone Traps ◽

Infection Level ◽

Ongoing Debate ◽

Flight Ability ◽

Spruce Bark

AbstractThe importance of pathogens in the population dynamics of Ips typographus remains a subject of ongoing debate. The main objective of our experiment was to compare the pathogen infection levels of individuals overwintering in bark with the levels of individuals from the same population captured with pheromone traps and thereby to determine primary answers as to whether it can be confirmed that pathogenic organisms affect the flight ability of bark beetles or their ability to leave their places of overwintering. A total of 402 I. typographus individuals were analyzed at a study location under limited management. Three pathogens were confirmed to be present: the gregarine Gregarina typographi, the virus ItEPV, and the microsporidium Nosema typographi. Infection levels of Gregarina typographi and ItEPV were the same in beetles collected at places of overwintering and in those beetles collected in pheromone traps within the immediate vicinity. As these pathogens infect the host’s intestine, the tendency to leave the places of overwintering is apparently not diminished. A similar analysis and comparison of pathogens located in the fat body might bring different results, as our study only detected N. typographi in a single dissected adult spruce bark beetle.

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Population dynamics of bark beetles, with special reference to Ips typographus: Introduction

Ecography ◽

10.1111/j.1600-0587.1989.tb00912.x ◽

1989 ◽

Vol 12 (4) ◽

pp. 382-382 ◽

Cited By ~ 2

Author(s):

Nils Chr. Stenseth ◽

Lawrence R. Kirkendall

Keyword(s):

Population Dynamics ◽

Special Reference ◽

Bark Beetles ◽

Ips Typographus

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

Forests ◽

10.3390/f11121290 ◽

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.

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A Highly Contiguous Genome Assembly of a Major Forest Pest, the Eurasian Spruce Bark Beetle Ips Typographus

10.21203/rs.3.rs-182683/v1 ◽

2021 ◽

Author(s):

Daniel Powell ◽

Ewald Grosse-Wilde ◽

Paal Krokene ◽

Amit Roy ◽

Amrita Chakraborty ◽

...

Keyword(s):

Bark Beetle ◽

Genome Assembly ◽

Bark Beetles ◽

Plant Cell Wall ◽

Draft Genome ◽

Ips Typographus ◽

Whole Genome Sequence ◽

Comparative Genomic ◽

Spruce Bark Beetle ◽

Spruce Bark

Abstract Conifer-feeding bark beetles are important herbivores and decomposers in forest ecosystems. These species have evolved specializations to complete their life cycle in nutritionally poor wooden substrates and some can overwhelm tree defences and kill enormous numbers of trees during population outbreaks. The Eurasian spruce bark beetle (Ips typographus) is one tree-killing species; during a recent epidemic it destroyed >100 million m3 of spruce in a single year. We report a 236 Mb, highly contiguous I. typographus genome assembly using PacBio long-read sequencing. The final phased assembly had a contig N50 of 6.65 Mb in 272 contigs and was predicted to contain 23,923 protein-coding genes. Comparative genomic analysis including 11 additional coleopterans revealed expanded gene families associated with plant cell wall degradation, including pectinases, aspartyl proteases, and glycosyl hydrolases. This first whole-genome sequence from the genus Ips provides timely resources to address important questions about the evolutionary biology of the true weevils (Curculionidae), one of the most species-rich animal families. This resource will also allow for improved studies of functional genomics of both fundamental and applied value. In forests of today, increasingly stressed by global warming, this draft genome may ultimately assist in developing novel pest control strategies to mitigate outbreaks.

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Catches of Ips duplicatus and other non-target Coleoptera by Ips typographus pheromone trapping

Entomologica Fennica ◽

10.33338/ef.83934 ◽

1997 ◽

Vol 8 (3) ◽

pp. 153-159 ◽

Cited By ~ 7

Author(s):

Heli Valkama ◽

Mika Räty ◽

Pekka Niemelä

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Ips Typographus ◽

Pheromone Traps ◽

Pheromone Trapping ◽

Ips Duplicatus ◽

Geographic Gradient ◽

First Time ◽

Eastern Finland ◽

Russian Karelia

Catches of non-target Coleoptera in Ips typographus pheromone traps baited with Ipslure® were analysed along a geographic gradient running from southwestem Finland to eastern Finland and Russian Karelia. Besides I. typographus, two other bark beetles, Pityogenes chalcographus and Ips duplicatus were caught in high numbers. I. duplicatus occuned on northeastern sites only, suggesting a more restricted distribution than previously known. High numbers of Thanasimus spp. beetles indicate that I. typographus pheromone is also an effective attractant for bark beetle predators. In addition, the originally North American ambrosia beetle Gnathotrichus materiarius, now widely spread in Europe was found for the first time in nature in Finland.

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Ursachen und Verlauf der Buchdrucker-Epidemien (Ips typographus L.) in der Schweiz von 1984 bis 1999 | Causes and progress of the eight-toothed spruce bark beetle epidemics (Ips typographus) in Switzerland from 1984 to 1999

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2003.0437 ◽

2003 ◽

Vol 154 (11) ◽

pp. 437-441 ◽

Cited By ~ 6

Author(s):

Franz Meier ◽

Rolf Gall ◽

Beat Forster

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

National Level ◽

Weather Conditions ◽

Ips Typographus ◽

Annual Data ◽

Storm Damage ◽

Spruce Bark Beetle ◽

Breeding Material ◽

Spruce Bark

In the past 20 years, several mass attacks by the eight-toothed spruce bark beetle (Ips typographus L.) occurred in Switzerland. Since 1984 data on compulsory fellings, numbers of infestation spots and numbers of beetles captured in pheromone traps have been collected in all Swiss forest districts. The annual data were published in short reports. This paper gives an overview of the progress of bark beetle epidemics from 1984 to 1999. On the national level, two periods with epidemics of the spruce bark beetle can be distinguished. The first epidemic started after windthrows and drought in the years 1982 and 1983. It reached its height in 1984/1985 and faded at the end of the decade. The second epidemic started after the storm Vivian (February 1990). It reached its height in 1992/1993 and ended in 1997. Storm damage that produced high quantities of suitable breeding material was not the only factor for the bark beetle gradation;weather conditions were also exceptional, such as hot and dry vegetation periods. Windthrows and exceptional weather conditions are mostly events on regional scales and do not affect the whole country with the same intensity. The gradation that appears to be an «epidemic of the spruce bark beetle in Switzerland after the storm Vivian» is in truth the accumulation of several local epidemics. This is shown by the number of compulsory fellings and infestation spots analysed at regional levels. Extreme weather conditions and storms not only directly influence the bark beetle population, they also stress standing trees, thus creating suitable breeding material for bark beetles. To analyse the influence of exceptional weather conditions on bark beetle epidemics,it is therefore necessary to evaluate regional data.

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An attempt to use the fungus Beauveria bassiana (Bals.) Vuill. in forest protection against the bark beetle Ips typographus (L.) in the field

Forest Research Papers ◽

10.1515/frp-2015-0001 ◽

2015 ◽

Vol 76 (1) ◽

pp. 5-17 ◽

Cited By ~ 4

Author(s):

Wojciech Grodzki ◽

Mieczysław Kosibowicz

Keyword(s):

Beauveria Bassiana ◽

Bark Beetle ◽

Bark Beetles ◽

Tree Mortality ◽

Ips Typographus ◽

Forest Environment ◽

Forest Protection ◽

Spruce Stands ◽

Insect Populations ◽

Fungus Beauveria Bassiana

Abstract In 2011-2013, trials on the use of the entomopathogenic fungus Beauveria bassiana against bark beetle (Ips typographus) populations were carried out under open field conditions in Norway spruce stands suffering from an outbreak in the Beskid Żywiecki Mts. in Poland. Modified pheromone traps were deployed to capture and thereafter release fungus-infected bark beetles to the forest environment. Infested spruce trees felled next to the traps remained unaffected by the transmission of the fungus to insect populations. Direct spraying or dusting of lying trap logs and suspended caged rearing bolts did not have any effect on spruce infestation by I. typographus, its reproduction success and development or natural enemies inside the bark. A very small effect on mortality rates of target as well as non-target insects overwintering in the dusted litter was observed. Treated stands, unlike control stands, were indirectly affected by the treatment, evidenced by the reduction of tree mortality due to bark beetle infestation. At present, no recommendations concerning the potential use of the fungus in forest protection can be given. However such an environmentally friendly approach represents a promising future prospect.

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Identification of male produced compounds in the bark beetle Polygraphus subopacus and establishment of (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol as an aggregation pheromone component

Chemoecology ◽

10.1007/s00049-021-00358-0 ◽

2021 ◽

Author(s):

Lina Viklund ◽

Joakim Bång ◽

Martin Schroeder ◽

Erik Hedenström

Keyword(s):

Bark Beetle ◽

Aggregation Pheromone ◽

Bark Beetles ◽

Ips Typographus ◽

Spruce Bark ◽

Volatile Organic ◽

Males And Females ◽

A Minor ◽

Male Specific ◽

Minor Compound

AbstractBark beetles of the genus Polygraphus have recently been involved in large bark beetle outbreaks in central Sweden, together with the European spruce bark beetle Ips typographus. Three species of Polygraphus can be found in this region; Polygraphus poligraphus, Polygraphus punctifrons and Polygraphus subopacus. Efficient pheromone traps would facilitate further investigations of these species and their role in bark beetle outbreaks. Pheromone compounds have previously been identified in P. poligraphus and P. punctifrons, but not in P. subopacus. Thus, we allowed males and females of P. subopacus to bore in the bark of stem sections of Norway spruce (Picea abies) in the laboratory. Volatile organic compounds from boring insects were sampled with SPME and analysed with GC–MS and several male-specific compounds were observed. The male specific compounds were 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 3-methyl-2-butenal, grandisol, fragranol, (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol, (E)-2-(3,3-dimethylcyclohexylidene)-ethanol, (Z)-2-(3,3-dimethylcyclohexylidene)-acetaldehyde, (E)-2-(3,3-dimethylcyclohexylidene)-acetaldehyde, geranial and γ-isogeraniol. (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol, [(Z)-DMCHE], was identified from GC–MS analysis to be the major male-specific compound while the (E)-isomer, [(E)-DMCHE], was found as a minor compound. These two compounds gave positive responses in EAG analyses with antennae from males and females of P. subopacus. Thus, (Z)- and (E)-DMCHE were used in a field experiment in central Sweden but only (Z)-DMCHE was found to be attractive to males and females of P. subopacus. Consequently, (Z)-DMCHE was established to be a component of P. subopacus aggregation pheromone.

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Efficacy of synthetic lures for pine bark beetle monitoring

Journal of Forest Science ◽

10.17221/139/2021-jfs ◽

2022 ◽

Vol 68 (No. 1) ◽

pp. 19-25

Author(s):

Miloš Knížek ◽

Jan Liška ◽

Adam Véle

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Large Scale ◽

Ips Typographus ◽

Pine Plantations ◽

The Czech Republic ◽

Long Run ◽

Baited Traps ◽

Pine Trees ◽

Ips Sexdentatus

The Scots pine (Pinus sylvestris) plantations in central Europe are currently damaged by a large-scale infestation by bark beetles (Scolytinae). Ips acuminatus and Ips sexdentatus are among the most aggressive species causing infestations of pine trees that are currently simultaneously attacked by Ips typographus. In pine plantations prone to damage, it is therefore necessary to carry out the bark beetle monitoring. One of the used methods is the pheromone bark beetle trapping using synthetic lures. The efficacy of synthetic lures differs. We tested the efficacy of commercially available lures used in the protection of pine trees. In total, we deployed 10 trap series, each consisting of traps with eight different lures and two unbaited traps (controls). Ips acuminatus and I. sexdentatus were most abundantly captured in Pheagr-IAC- and Sexowit-baited traps. Interestingly, the spruce species I. typographus was also captured and most often found in traps with Pheagr-IAC and Erosowit Tube lures. The number of captured beetles was consistent with the gradation phase of bark beetles. Our results suggest the suitability of pheromone traps for bark beetle monitoring. The use of Sexowit can be recommended especially in southwestern Moravia, where I. sexdentatus occurs in high numbers in the long run. In other parts of the Czech Republic, Pheagr-IAC alone can be used with sufficient efficacy. The use of the Erosowit Tube lure is also suitable for I. typographus and I. sexdentatus monitoring.

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