Control Of Bark Beetles Research Articles

Biorhythm paralleled release of pheromone by photothermal conversion for Long-term bark beetle control

The spruce bark beetle Ips typographus, as the most notorious pest in Eurasia spruce forest ecosystem, mainly feed on phloem of spruce tree trunk. The concealment of their habit makes regulation of insect population a difficulty to cope with, contributing to spruce forest recession, destruction of environment balance and forest transformation from carbon sinks into carbon source. Based on the cross point between the biorhythm of the I. typographus and photothermal material, description herein was a novel sunlight-triggered biorhythm-paralleled photothermal sponge (BPPS) for continuous control of I. typographus. Three steps including preparation of sugar template based porous polyurethane (PU) sponge, polypyrrole (PPy) modification and pheromone filling were involved in material manufacturing. The attractant and repellant agents were employed into the PU separately to realize a comprehensive regulation on I. typographus behavior. Laboratory simulation and forest field experiments illustrated that both the rapid release within a short period and long-term effectiveness in 21 days were verified. Due to the advantages of designability, cost-effectiveness and environmental friendliness of our sustained-release sponge, this manufacturing strategy offers great promise for generating photothermal responsive sustained-release material, shedding light on long-term control of injurious trunk borers and environmental protection.

Diversity and prevalence of entomopathogenic fungi (Ascomycota, Hypocreales) in epidemic populations of bark beetles (Coleoptera, Scolytinae) in spruce forests of the Tatra National Park in Slovakia

Bark beetles are serious pests for forestry in Slovakia. Their outbreaks may have significant ecological and economic impacts on spruce forests. Effective control of bark beetles is difficult due to their cryptic habits, however, microbial control using entomopathogenic fungi is believed to be a promising alternative to traditional control measures. During 2014–2015, diversity and prevalence of entomopathogenic fungi was studied in populations of bark beetles infesting spruce forests affected by windstorms in the Tatra National Park in Slovakia. Three Beauveria species, B. bassiana , B. caledonica and B. pseudobassiana , together with Metapochonia bulbillosa were identified from 271 specimens of three bark beetle species, Ips typographus , Ips amitinus and Pityogenes chalcographus . Beauveria bassiana was the predominant pathogen and infected all three bark beetle species. Phylogenetic analysis identified three phylogenetic groups of B. bassiana in the evaluated host populations. M. bulbillosa was reported for the first time from bark beetle hosts and Slovakia. The prevalence of fungal infection in natural populations of I. typographus was low and varied between 0.07 and 0.72%.

Pinyon Engraver Beetle Acoustics: Stridulation Apparatus, Sound Production and Behavioral Response to Vibroacoustic Treatments in Logs.

Simple SummaryAcoustic technology is a potential tool to protect wood materials and live trees from colonization by bark beetles and other wood-infesting insects. Bark beetles such as the pinyon engraver beetle Ips confusus use chemical and acoustic cues to communicate and to locate potential mates in trees. In this study, we describe the structures and airborne sounds produced by the pinyon engraver beetle, and test the efficacy of vibroacoustic treatments for tree protection against this beetle. Only female beetles possessed sound producing structures, located on the back of the head and inside the thorax. We analyzed and described the airborne sounds, called chirps, produced by females when held by tweezers or placed on their back. We tested a wide variety of vibroacoustic treatments played into logs but these sound treatments did not prevent male entry into logs and did not disrupt female–male interactions, female tunneling behavior, reproduction or egg laying. We suggest further studies if acoustic methods are to be utilized to control this bark beetle.Bark beetles are among the most influential biotic agents in conifer forests, and forest management often focuses on bark beetle chemical communication for tree protection. Although acoustic communication occurs in many bark beetle species, we have yet to utilize acoustic communication for bark beetle control. Here, we describe the stridulatory organs and ‘stress’ chirps of the pinyon engraver, Ips confusus, a significant pest and mortality agent of pinyon pine in western North America. Only females possessed stridulatory organs and their stress chirps varied significantly in duration, pulses per chirp, and dominant frequency. We tested an array of acoustic-vibrational treatments into logs but were unable to disrupt male entry into logs or alter female–male interactions, female tunneling, and female oviposition. We found acoustic–vibrational treatments had little effect on I. confusus behavior and suggest further studies if acoustic methods are to be utilized for bark beetle control.

National Forest Inventories capture the multifunctionality of managed forests in Germany

BackgroundForests perform various important ecosystem functions that contribute to ecosystem services. In many parts of the world, forest management has shifted from a focus on timber production to multi-purpose forestry, combining timber production with the supply of other forest ecosystem services. However, it is unclear which forest types provide which ecosystem services and to what extent forests primarily managed for timber already supply multiple ecosystem services. Based on a comprehensive dataset collected across 150 forest plots in three regions differing in management intensity and species composition, we develop models to predict the potential supply of 13 ecosystem services. We use those models to assess the level of multifunctionality of managed forests at the national level using national forest inventory data.ResultsLooking at the potential supply of ecosystem services, we found trade-offs (e.g. between both bark beetle control or dung decomposition and both productivity or soil carbon stocks) as well as synergies (e.g. for temperature regulation, carbon storage and culturally interesting plants) across the 53 most dominant forest types in Germany. No single forest type provided all ecosystem services equally. Some ecosystem services showed comparable levels across forest types (e.g. decomposition or richness of saprotrophs), while others varied strongly, depending on forest structural attributes (e.g. phosphorous availability or cover of edible plants) or tree species composition (e.g. potential nitrification activity). Variability in potential supply of ecosystem services was only to a lesser extent driven by environmental conditions. However, the geographic variation in ecosystem function supply across Germany was closely linked with the distribution of main tree species.ConclusionsOur results show that forest multifunctionality is limited to subsets of ecosystem services. The importance of tree species composition highlights that a lack of multifunctionality at the stand level can be compensated by managing forests at the landscape level, when stands of complementary forest types are combined. These results imply that multi-purpose forestry should be based on a variety of forest types requiring coordinated planning across larger spatial scales.

Identification of Fungi Associated to <i>Pseudips mexicanus</i> (Curculionidae: Scolytinae) as a Possible Biocontrol Agent

Entomopathogenic fungi are an important insect biological control group, however most of the fungi described as biological controllers have a broad spectrum of insect hosts. Pseudips mexicanus is a bark beetle that infests pine-oak forests in Mexico, causing significant economic and ecologic losses. In addition, the infestation alters the ecology of different organisms that coexist in the forest habitat. The search for bark beetle control methods other than pesticides has led to research into biological control procedures based on naturally occurring beetle pathogens. The goal of this paper was the isolation, morphological and molecular identification of fungi that naturally parasitize the bark beetle Pseudips mexicanus, as well as to carry out infection tests to propose a specific biological control alternative to this plague. Associated to this beetle, we have identified four isolates belonging to three genus: Beauveria, Lecanicillium and Trichoderma, within these some species have been used previously as biocontrollers, mainly in agricultural use, in the process of transformation of organic crops. The LVP-2 isolated, which was identified as Beauveria was tested for infection of naturally harvested bark beetles and its pathogenicity was proved, at three days post infection (dpi) most of the individuals presented little mobility of the legs and a swelling of the body was noted, however more studies are needed to determine their viability as plague controllers in Mexican forests.

Semiochemicals for bark beetle (Coleoptera: Curculionidae) management in western North America: where do we go from here?

AbstractThis paper is intended as an assessment of the state of knowledge and development of semiochemical methods for control of bark beetles (Coleoptera: Curculionidae) in western North America and as a roadmap for future research and development in this field. It is based on a keynote presentation given at the symposiumManaging Bark and Ambrosia Beetles with Semiochemicals, held in 2018 in Vancouver, British Columbia, Canada, at the Joint Meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia. We describe currently available active ingredients, formulations, and release devices. Furthermore, we describe the most urgently needed new products and techniques, and constraints to their further development. Finally, we speculate about opportunities afforded by new advances in microbial synthesis of semiochemicals, streamlining of regulatory processing, and aerial application using unmanned aerial vehicles.

Orman Alanlarında Kabuk Böceklerinin (Coleoptera: Curculionidae, Scolytinae) Mücadelesinde Monoterpenlerin Kullanımı

Kabuk böcekleri (Coleoptera: Curculionidae) dünyada ve Türkiye‘de ormanların önemli zararlıları arasındadır. Kabuk böcekleri, monoterpenlerle davranışsal, fizyolojik ve biyokimyasal etki yolu oluşturarak konukçu ağaçlarla kimyasal olarak etkileşime girmektedir. Ormanlarda bulunan çam, ladin ve köknar gibi ağaçlar tarafından üretilen oleoresinin yaklaşık yarısı monoterpenlerdir. Monoterpenler, çam kabuğu böcekleri ve avcıları için davranışsal olarak aktif kairomonlar olarak işlev görmekte ve tritrofik kimyasal iletişimin klasik bir örneğini sunmaktadır. Monoterpenler, kabuk böceklerinin toplanma feromonlarıdır. Kabuk böcekleriyle mücadelede monoterpenler, tuzaklar içerisinde kullanılmaktadır. Myrcene tuzaklarda, sinejist bir etki göstermektedir. Monoterpenler, böcekler için toksik olabilmektedir. Kabuk böceklerine en toksik monoterpenler arasında, limonene bulunmaktadır. Ayrıca monoterpenler ve kabuk böceklerinin avcıları arasında bir ilişki vardır. Monoterpenler, kabuk böceklerinin feromonlarına predatörlerin tepkisini arttırmaktadır.

Education and knowledge determine preference for bark beetle control measures in El Salvador

Extensive outbreaks of bark beetles have affected not only large parts of coniferous forests in the Northern Hemisphere, but also — largely absent from global attention — native pine forests of Central America. As such outbreaks frequently spark management debates among residents, land managers, forest owners and the public, the social acceptance of bark beetle control measures has become crucial for modern land management. However, the sociological and psychological determinants of the preference for specific bark beetle control measures outside protected areas remain unclear. To determine the acceptability of bark beetle control measures in El Salvador, we assessed how demographic variables, attitude towards the bark beetle, education, and self-reported knowledge affected the preference for different bark beetle control measures in a survey of government employees and local forest owners using a quantitative questionnaire survey. Cumulative link mixed models revealed that the general preference for control measures increased with increasing self-reported knowledge about the bark beetle but decreased with increasing level of respondent education and an increasing positive attitude towards the bark beetle. Respondents generally preferred beetle control measures on small areas than on large areas. Preferences for control measures did not differ between government employees and forest owners, with controlled burning and chemical control significantly less accepted than stand thinning or salvage logging. We discuss the most preferred control measures considering recent scientific evidence of their efficacy and conclude that the current bark beetle outbreak should be controlled through logging of pines weakened by fire in the short-term and by stand thinning in the medium-term to prevent further outbreaks.

Reconciling pest control, nature conservation, and recreation in coniferous forests

AbstractProtected areas are not only crucial for biodiversity and natural processes but also for recreation. Although a benign neglect strategy of dealing with natural disturbances in protected areas is beneficial for nature, public debate on avoiding increased pest population growth has intensified. We evaluated the effect of mechanical pest control measures in decreasing populations of insect pests, maintaining nontarget biodiversity, retaining high recreational value, and keeping economic costs low. Debarking and bark scratching or gouging effectively prevented infestation of felled trees by European spruce bark beetles (Ips typographus) and controlled the beetles in recently infested trees. Bark scratching or gouging retained biodiversity at natural levels, whereas debarking decreased biodiversity by 54% with higher economic costs. The public rated bark‐gouged trees more positively than debarked trees. We thus urge authorities to promote bark scratching or gouging in the control of bark beetles in protected areas instead of salvage logging and debarking.

Hypocrealean fungi associated with populations of Ips typographus in West Carpathians and selection of local Beauveria strains for effective bark beetle control

In Slovakia, a diversity of entomopathogenic fungi (Ascomycota, Hypocreales) associated with outbreaks of Ips typographus was studied in 81 localities and as many as 113 in vitro cultures of five entomopathogenic species were isolated from infected individuals: Beauveria bassiana (87 isolates), B. pseudobassiana (14 isolates), B. caledonica (6 isolates), Lecanicillium lecanii (4 isolates) and Isaria farinosa (2 isolates). B. pseudobassiana is recorded in natural populations of I. typographus for the first time. Biological properties of selected Beauveria isolates, including colony growth, biomass production, conidia yield and pathogenicity to I. typographus adults, were studied in a series of laboratory bioassays and much intra- and interspecific variability was detected. B. bassiana isolates produced biomass or conidia at significantly higher rate than B. pseudobassiana and B. caledonica isolates. Two B. bassiana isolates were selected as the most virulent to bark beetle adults, demonstrating a mean LC50 ranging from 0.72 to 2.05 × 106 conidia ml−1, and were qualified as promising candidates for biocontrol of I. typographus. Their virulence was significantly higher than that of the mycoinsecticides Boverol®, which was used as a reference strain in the virulence bioassays.

Effects of γ radiation on the reproduction and enteroendocrine cells of the spruce bark beetle Ips typographus and prospects for its control

The European spruce bark beetle Ips typographus is one of the most important pests of spruce forests in Europe. The present study investigated the feasibility of a sterile insect technique (SIT) for this pest control. Laboratory-reared males were exposed to various doses of γ radiation (0, 10, 30, 50, 70 and 90 Gy) and allowed to mate with laboratory-reared untreated females. The radiation significantly affected the number of viable offspring. Although females oviposited on average 16.0–18.8 eggs per maternal tunnel in all treatments, the number of larval tunnels per maternal tunnel observed after 4 weeks of development decreased from 17.3 in the control (0 Gy) to 4.5 in the 90-Gy group. Numerous oviposition sites without larval tunnels were observed in galleries when males received high doses (70 and 90 Gy) of γ radiation. Comparison of the sperm viability in the control and irradiated males did not reveal any statistically significant differences. Side effects of the irradiation were examined by immunostaining of the enteroendocrine cells. Two distinct types of cells were revealed with antibodies to neuropeptides allatostatin A and tachykinin in the midgut. The alimentary tracts of males receiving a high dose of radiation (90 Gy) showed a significantly decreased number of tachykinin-like immunoreactive enteroendocrine cells. This observation suggests potential radiation-induced damage of the digestive system, which could lead to a reduction in male fitness. The implications of these findings for successful use of SIT in spruce bark beetle control are discussed.

Felled trap trees as the traditional method for bark beetle control: Can the trapping performance be increased?

Felled trap trees have been traditionally used to control bark beetles in central Europe. There is, however, little research on the method and on factors affecting trap tree performance. We therefore evaluated the effect of felling date, tree diameter, site shading, and weather conditions on the pattern of trap tree infestation by bark beetles. An experiment was conducted at two localities with contrasting forest damage rates and bark beetle outbreak phases in the Czech Republic during three periods: December to April of 2004–2005, 2005–2006, and 2006–2007. For each of the three periods, eight dates of trap tree felling were equally spaced. On each date and at each locality, 5–7 trees located at the open forest edge were felled (295 trap trees in total). The number of Ips typographus (Linnaeus, 1758) entry holes dm−2 counted in May each year was used as the response variable. Neural network-based regression models were used to identify the variables that most affected trapping performance.The performance of the regression models in terms of Pearson’s correlation between observed and predicted entry hole densities ranged from 0.15 to 0.93. The effect of predictor variables on the recorded entry hole density was much lower in the forest with a culminating bark beetle outbreak than in the forest with outbreak in retrogradation phase. For trap trees felled before winter, trapping performance was positively associated with the length of the period that the trap trees were covered by snow. The trap trees exposed to higher heat sums tended to show lower entry hole density than trap trees exposed to lower heat sums.The results indicate that, in forests with high beetle densities, there are few options for increasing trap tree performance based on selection of specific sites, tree characteristics, or felling dates. The identified sensitivity of trap trees to weather indicates that trees should be felled just before beetles emerge if conditions have been relatively warm and snowless but can be felled far in advance under cooler conditions with regular snow. Finally, the results indicate that foresters should continue to use large-diameter trees located on non-shaded sites as felled trap trees.

Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control.

Conifer bark beetles attack and kill mature spruce and pine trees, especially during hot and dry conditions. These beetles are closely associated with ophiostomatoid fungi of the Ascomycetes, including the genera Ophiostoma, Grosmannia, and Endoconidiophora, which enhance beetle success by improving nutrition and modifying their substrate, but also have negative impacts on beetles by attracting predators and parasites. A survey of the literature and our own data revealed that ophiostomatoid fungi emit a variety of volatile organic compounds under laboratory conditions including fusel alcohols, terpenoids, aromatic compounds, and aliphatic alcohols. Many of these compounds already have been shown to elicit behavioral responses from bark beetles, functioning as attractants or repellents, often as synergists to compounds currently used in bark beetle control. Thus, these compounds could serve as valuable new agents for bark beetle management. However, bark beetle associations with fungi are very complex. Beetle behavior varies with the species of fungus, the stage of the beetle life cycle, the host tree quality, and probably with changes in the emission rate of fungal volatiles. Additional research on bark beetles and their symbiotic associates is necessary before the basic significance of ophiostomatoid fungal volatiles can be understood and their applied potential realized.Electronic supplementary materialThe online version of this article (doi:10.1007/s10886-016-0768-x) contains supplementary material, which is available to authorized users.

Just how many obstacles are there to creating a National Park? A case study from the Šumava National Park

This case study reports the recent history and evaluates the socio-economic constraints on nature conservation in the Bohemian Forest, which is the largest natural wilderness area in the central European cultural landscape. This gradually occurred over the past half of century, when nature was allowed to reclaim the most valuable parts along the common Czech–German border and the national parks (NP) were established: the Bavarian Forest NP in Germany (in 1970) and the Šumava NP in the Czech Republic (1991). Unfortunately, since the very beginning of the Šumava NP, its status has been questioned, compromised or debated, and it never received clear political support. Discussions about its future have become never-ending and were only on the appropriate management of the forests, i.e. “non-intervention” management versus “necessary” bark-beetle control. The “bark beetle problem”, however, is a wildcard issue that has obscured much more complex problems. This paper is the first attempt to describe the main obstacles and offer some solutions for making the Šumava NP a successful and sustainable project.

More than a pest management tool — 45 years of practical experience with insect pheromones in stored-product and material protection

The application of pheromone-baited traps to control pest insects in stored food or materials has become well established over the past decades. The main pheromone components of all major stored-product and material pests have been identified. Pest monitoring with pheromone traps is a key factor in integrated pest management to estimate population density build-ups and they may be used to define economic threshold levels. Male-attracting sex pheromones, e.g. for stored-product pyralids, the clothes moths, and some anobiid beetles, are especially effective in this aspect. Monitoring pest population can facilitate optimal spatial and temporal control strategies, including efficacy evaluation of the implemented control measures. In addition to the sex pheromones, some beetles, such as grain and flour beetles, utilize aggregation pheromones, which attract both sexes. Implementation of these pheromones for mass trapping, which works well for the control of bark beetles in the forest environment, has been less successful for stored-product protection for various reasons and is thus not an established means of control. When the monitoring tools are used in landscape areas, scrublands, forests, and away from anthropogenic influenced environments, natural reservoirs of a pest species and sources of new infestations can be identified. In addition to an economically driven adoption of pheromone traps, they may also provide information of a pest’s general biology. Because stored-product and material pests must be considered neozoons in most parts of the world, their occurrence in natural habitats indicates a species’ autecological capability to successfully compete with native species and to become fau-nistically established in non-synanthropic environments outside their zoogeographic origin. This review focuses on the use of pheromone traps for monitoring in outdoor situations.

Effectiveness of different trap types for control of bark and ambrosia beetles (Scolytinae) in Criollo cacao farms of Mérida, Venezuela

Scolytid wood-boring beetles, especially Xyleborus spp., are among the most harmful cacao (Theobroma cacao) pests in Venezuela because of their mutualistic association with a fungus (Ceratocystis cacaofunesta) that causes cacao wilt. The Criollo varieties of cacao are very susceptible to pests and diseases. We tested the effectiveness of two kinds of trap for collecting scolytids: bottle traps with windows (situated at 1 m and 3 m above ground level) and funnel traps, placed in a cacao farm south of Maracaibo Lake, Mérida state. Funnel traps collected significantly more individuals than bottle traps. The scolytid assemblages collected by each kind of trap were dissimilar, having only 60% of species in common.

Bark Beetles and their Natural Enemies on Oriental Spruce from the Black Sea Region of Turkey

Oriental spruce, Picea orientalis (L.) Link. (Pinaceae), is one of the main tree species that naturally grows in the Caucasus Mountains and the northeastern part of Turkey, known as the Black Sea Region. This tree species reaches optimal growth in the mountainous areas of heavy precipitation in Ordu, Giresun, Rize, Trabzon, and Artvin Provinces of the Eastern Black Sea Region of Turkey, but it can tolerate a wide range of climatic zones. The bark beetle species (Coleoptera: Curculionidae: Scolytinae) that attack oriental spruce, and their predators and parasitoids, were studied in Turkey in 2005–2006. Twenty-three species of bark beetles belonging to six subtribes and two tribes of Scolytinae were identified. In addition, 84 predatory species from 21 families and 23 parasitoid species from five families were detected. Identification of these predatory and parasitic species is an important starting point for the biological control of bark beetles attacking oriental spruce in Turkey.

Impacts of Silvicultural Thinning Treatments on Beetle Trap Captures and Tree Attacks During Low Bark Beetle Populations in Ponderosa Pine Forests of Northern Arizona

Our research used a combination of passive traps, funnel traps with lures, baited trees, and surveys of long-term thinning plots to assess the impacts of different levels of stand basal area (BA) on bark beetle tree attack and on trap captures of Ips spp., Dendroctonus spp., and their predators. The study occurred at two sites in ponderosa pine, Pinus ponderosa Dougl. ex Laws., forests, from 2004 to 2007 during low bark beetle populations. Residual stand BA ranged from 9.0 to 37.0 m2/ha. More predators and bark beetles were collected in passive traps in stands of lower BA than in stands of higher BA; however, significance varied by species and site, and total number of beetles collected was low. Height of the clear panel passive traps affected trap catches for some species at some sites and years. When pheromone lures were used with funnel traps [Ips pini (Say) lure: lanierone, +03/-97 ipsdienol], we found no significant difference in trap catches among basal area treatments for bark beetles and their predators. Similarly, when trees were baited (Dendroctonus brevicomis LeConte lure: myrcene, exo-brevicomin and frontalin), we found no significant difference for days to first bark beetle attack. Surveys of long-term thinning treatments found evidence of bark beetle attacks only in unthinned plots (approximately 37 m2/ha basal area). We discuss our results in terms of management implications for bark beetle trapping and control.

Forest composition following overstory mortality from southern pine beetle and associated treatmentsExperiment Station Project 06-08-109 of the Kentucky Agricultural Experiment Station, Lexington, Kentucky.

Bark beetle caused mortality continues to play a critical role in determining the composition and structure of forests in North America, and revegetation dynamics following these disturbances are poorly understood. We assessed forest composition following southern pine beetle, Dendroctonus frontalis Zimmermann, mortality and associated cut and leave suppression, and compared them with undisturbed loblolly pine, Pinus taeda L., stands in Texas. Abundant hardwood regeneration dominated the understory, with little loblolly pine regeneration following either mortality event. Disturbances eliminated loblolly pine dominance in these even-aged stands, thus stratifying forest structure and apparently increasing stem density (stems·ha–1), richness (species·ha–1), and diversity (ha) in the lower strata. Aspect and elevation, presumably through influences on site moisture, were the primary gradients associated with vegetation variation in the canonical correspondence analyses for new regeneration. Mortality from Dendroctonus and cut and leave practices shifted loblolly pine communities to mixed upland hardwoods in model predictions generated by the southern variant of the Forest Vegetation Simulator. In addition to being an effective bark beetle control, cut and leave suppression did not alter predicted forest composition 50 years hence when compared with unsuppressed bark beetle-caused mortality. Because of the predicted shift to hardwood domination and a low pine basal area, it is expected that mortality from D. frontalis and cut and leave will substantially reduce future hazards from D. frontalis outbreaks.

Selective manipulation of predators using pheromones: responses to frontalin and ipsdienol pheromone components of bark beetles in the Great Lakes region

Abstract 1 One proposed approach to improving biological control of bark beetles (Coleoptera: Scolytidae; alt. Curculionidae: Scolytinae) is to manipulate predator movement using semiochemicals. However, selective manipulation is impeded by attraction of both predators and pests to bark beetle pheromones.2 The primary bark beetle affecting pine plantations in Wisconsin, U.S.A., is the pine engraver, Ips pini (Say). Other herbivores include Ips grandicollis (Eichhoff) and Dryophthorus americanus Bedel (Curculionidae). The predominant predators are the beetles Thanasimus dubius (Cleridae) and Platysoma cylindrica (Histeridae).3 We conducted field assays using two enantiomeric ratios of ipsdienol, and frontalin plus α‐pinene. Ipsdienol is the principal pheromone component of I. pini, and frontalin is produced by a number of Dendroctonus species. α‐Pinene is a host monoterpene commonly incorporated into commercial frontalin lures.4 Thanasimus dubius was attracted to frontalin plus α‐pinene, and also to racemic ipsdienol. By contrast, I. pini was attracted to racemic ipsdienol, but showed no attraction to frontalin plus α‐pinene. Platysoma cylindrica was attracted to 97%‐(–)‐ipsdienol and, to a lesser extent, racemic ipsdienol, but not to frontalin plus α‐pinene. Ips grandicollis was attracted to frontalin plus α‐pinene but not to ipsdienol. Dryophthorus americanus was attracted to both ipsdienol and frontalin plus α‐pinene.5 This ability to selectively attract the predator T. dubius without attracting the principal bark beetle in the system, I. pini, provides new opportunities for research into augmentative biological control and basic population dynamics. Moreover, the attraction of T. dubius, but not P. cylindrica, to frontalin plus α‐pinene creates opportunities for selective manipulation of just one predator.6 Patterns of attraction by predators and bark beetles to these compounds appear to reflect various degrees of geographical and host tree overlap with several pheromone‐producing species.