Hylastes Ater Research Articles

Distribution, Invasion History, and Ecology of Non-native Pine Bark Beetles (Coleoptera: Curculionidae: Scolytinae) in Southern South America.

The growth of international trade, coupled with an expansion of large-scale pine plantations in South America during the second half of the twentieth century, has significantly increased the opportunities for the invasion of forest insects. Bark beetles (Coleoptera: Curculionidae, Scolytinae) are a large and diverse group of insects, commonly recognized as one of the most important tree mortality agents in coniferous forests worldwide and an important group among invasive forest species. In this study, we combined data from field sampling with published records of established non-native pine bark beetles, to describe their distribution and invasion history in pine plantations across southern South America, reviewing the available information on their phenology and host range. We obtained records of established populations of six Eurasian species distributed in two major regions: the southwest region comprises plantations in Chile and the Argentine Patagonia, with four bark beetle species: Hylastes ater, Hylastes linearis, Hylurgus ligniperda, and Orthotomicus laricis; the northeastern zone includes northeastern Argentina, Uruguay, and southern Brazil, and includes three bark beetle species: Cyrtogenius luteus, H. ligniperda, and O. erosus. The establishment of non-native populations across the study area began in the 1950s, and from the 1980s onwards, there has been an exponential increase in introductions. We predict that several of these species will continue spreading across South America and that new species will continue arriving. We highlight the importance of international collaboration for early detection and management of non-native pine bark beetles.

Temperature Effects on the Survival and Development of Two Pest Bark Beetles Hylurgus ligniperda F. (Coleoptera: Curculionidae) and Hylastes ater Paykull (Coleoptera: Curculionidae).

Hylurgus ligniperda (F.) and Hylastes ater (Paykull) are secondary bark beetles that have successfully spread beyond their native range, particularly into Pinus spp. plantations in the Southern Hemisphere. They feed on the phloem and cambial regions of highly stressed and recently dead Pinus spp. Here H. ligniperda and H. ater egg, larval, and pupal survival and development rates were modeled. Survival was variably influenced by temperatures depending on the life stage, but general trends were for H. ligniperda to tolerate warmer temperatures in comparison to H. ater. Nonlinear models showed 26, 29, and 34°C are the optimal temperature (maximum development rates) for the development of eggs, larvae, and pupae of H. ligniperda. In contrast, optimal temperature predictions were lower for H. ater, with estimates of 26, 22, and 23°C for the development of eggs, larvae, and pupae, respectively. H. ligniperda pre-imaginal stages were more tolerant to high temperatures, and H. ater pre-imaginal stages were more tolerant to low temperatures. Understanding the thermal requirements and limits for development for these two pests can assist in modeling emergence times, their current and potential species distribution and have potential phytosanitary applications.

Hylastes ater (black pine bark beetle)

Hylastes ater (black pine bark beetle)

New insights into the role of phytopathogenic fungi vectored by pine bark beetles in pine decline

The study presented was carried out in response to the alarmingly increasing number of outbreaks of bark beetles and associated fungi in European forests including Ukraine. Our study was aimed to generate new knowledge on bark beetles and understand the possible role of vectored fungi. The obtained data can contribute to the increased knowledge and will allow adequately responsing to an expected intensification of bark beetle disturbances, as well as may allow better understanding tree diseases and how to cope with them. In total, eleven ophiostomatoid fungi (Graphium sp., Leptographium sosnaicola, Grosmannia olivacea, Grosmannia penicillata, Ophiostoma bicolor, O. ips, O. canum, O. piceae, O. minus, O. nigrocarpum Graphilbum rectangulosporium) were found here in association with five species of bark beetles (Hylurgus ligniperda, Hylastes ater, Hylastes angustatus, Ips acuminatus and Ips sexdentatus) on Scots pine trees infested by bark beetles. Scots pine seedlings were inoculated with ophiostomatoid fungi and sterile medium (control) to evaluate their pathogenicity. The inoculated seedlings were examined finally 6 months later after inoculation. Inoculation with Leptographium sosnaicola, Graphium sp and O. minus produced significantly large lesions and mortality of pine seedlings. In total, all the eight fungal-inoculated species caused resin exudation and staining on the bark around inoculations in Scots pine seedlings and different rate of the seedlings decline.
 It can be concluded that the studied bark beetles are vectors for different functional groups of fungi including aggressive pathogens, and that ophiostomatoid fungi are the most closely associated symbionts. Moreover, high virulence fungi can help bark beetles to overcome the tree resistance and may significantly contribute to tree mortality.

First record of Bursaphelenchus hildegardae Braasch et al., 2006 (Nematoda) in New Zealand with updated information on morphology, sequencing and a key to species of the eggersi-group.

Bursaphelenchus hildegardae Braasch et al., 2006 was collected from pine wood (Pinus radiata) growing in Kaingaroa Timberlands, and a bark beetle, Hylastes ater Paykull, 1800 in New Zealand. This is a new record for B. hildegardae, occuring in New Zealand, and the second report from the southern hemisphere in addition to Australia. In general, the New Zealand isolate of B. hildegardae corresponds well with the description of B. hildegardae given by Braasch et al. (2006) from Germany. The New Zealand isolate is characterized by having an adult body length of 8071190 m, medium a ratios (47.558.5 for female and 44.660.1 for male), b ratios of 9.814.5 (female) and 10.212.7 (male), c ratios of 18.825.2 (female) and 21.632.4 (male), c ratios of 4.04.4 (female) and 2.12.7 (male), and is characterised by having three incisures in the lateral fields, thorn-shaped spicules with a distinctly dorsally-bent thin hook-like condylus, and a dorso-ventally visible terminal bursa. In addition, molecular phylogeny using near full length small subunit (SSU), D2/D3 expansion segments of the large subunit (LSU) and the internal transcribed spacer region (ITS1 and 2) of the ribosomal rDNA supports the identification. A key to Bursaphelenchus species in the eggersi-group is given.

Effect of Host Volatile Release Rate and Racemic Fuscumol on Trap Catch of Hylurgus ligniperda, Hylastes ater (Coleoptera: Curculionidae), and Arhopalus ferus (Coleoptera: Cerambycidae).

Early detection of bark- and wood-boring beetles is critical to support the eradication of recently established populations in novel regions. Flight intercept traps baited with semiochemical lures are essential for surveillance and population monitoring of introduced insects. We present laboratory and field data to test potential improvements in trap sensitivity to detect Hylastes ater (Paykull), Hylurgus ligniperda (Fabricius) (Coleoptera:Scolytinae), and Arhopalus ferus (Mulsant) (Coleoptera:Cerambycidae). We evaluated the effects of type and permeability of plastic material on release rates of host-plant volatiles and the addition of the pheromone racemic E-fuscumol on beetle species catch within an exotic Pinus radiata (D. Don) plantation forest. We trapped 228,278 H. ligniperda, 91 H. ater, and 2,504 A. ferus over two experiments. Our results show strong attraction of H. ligniperda to host-plant volatiles with a positive relationship between increased release rates and trap catch. H. ater follows this trend, with attraction to ethanol and (-)-β-pinene. H. ligniperda was more strongly attracted to host volatiles than H. ater, the average ratio between baited and unbaited traps being 51.25:1 and 3.75:1, respectively for each species. There was no effect of host-plant volatiles or release rate on A. ferus catch, but a weak attraction by A. ferus to racemic E-fuscumol. Overall, we demonstrate species-specific differences in Coleoptera attraction to host-plant volatile release rates and semiochemical blends. Results demonstrate mechanisms to improve trap catch of H. ligniperda and H. ater. Racemic E-fuscumol shows some promise for A. ferus, but further investigation is required to determine whether chirality affects attraction.

Bark beetles on pine logs: forecasting winter colonisation dynamics based on trap catches and temperature records

Seasonality influences the abundance and activity of forest insects. Harvesting during periods of reduced activity could minimise colonisation risk on logs and reduce the need for phytosanitary treatments. We describe the winter colonisation dynamics of Pinus radiata logs in operational harvest sites in New Zealand and assess the probability of log colonisation as a function of captures in flight interception traps. After 15 days, 3% and 1% of logs were colonised by Hylastes ater and Hylurgus ligniperda (Coleoptera: Scolytinae), respectively, and 1% by Xenocnema spinipes (Coleoptera: Curculionidae). The same three species were captured in traps. Our observations showed that logs exposed for ≥ 2 weeks are predicted to have a more than 1% probability of bark beetle colonisation, whereas logs removed from forests within 24 or 48 h had predicted colonisation rates of 0.13% and 0.26%, respectively. A positive relationship between trap capture and log colonisation was also observed. Average catches of 98% log colonisation. A positive relationship was also shown between log colonisation rates and temperature. A 12.3 °C temperature threshold predicted colonisation rates of 5, 50 and 95% with thermal sums of 10, 20 and 30 degree-hours, respectively. Models based on exposure time, trap catches, or environmental factors can estimate seasonal probability of insect colonisation, which aids identification of periods of low pest pressure when treatments could be avoided or reduced.

Flight activity of wood- and bark-boring insects at New Zealand ports

Background: Bark- and wood-boring forest insects spread via international trade. Surveys frequently target new arrivals to mitigate establishment. Alternatively, monitoring pest activity in exporting countries can inform arrival and establishmentrisk. Methods: We report >3 years data from daily sampling of bark- and wood-boring insects that are associated with recently felled Pinus radiata D.Don at five New Zealand ports. Results: Average catch differed between ports and months with Arhopalus ferus (Mulsant), Hylurgus ligniperda F., and Hylastes ater (Paykull) comprising 99.6% of the total catch. Arhopalus ferus was absent during winter with Hylastes ater and Hylurgus ligniperda activity between June and August representing 3.5 and 3.7% of total catch, respectively. Maximum temperature and wind speed influenced flight activity of all three species but not universally across all ports. Flight activity transitioned to a nonlinear pattern above 20°C. Arhopalus ferus has a unimodal flight risk period between late-September and late-April. Hylastes ater was also unimodal except in Dunedin where it was bimodal like Hylurgus ligniperda was in all regions with spring and mid- to late-summer activity periods. Although Hylastes ater was observed during winter, the probability of a flight event during winter was between 0 and 0.02 per week. Hylurgus ligniperda flight probability was zero in Dunedin and low at all other ports from May to August. Conclusions: Modelling seasonal changes in flight probability can inform risk-based phytosanitary measures. We demonstrate the utility of maximum temperature and seasonality as a predictor of wood commodity infestation risk. Such predictors allow National Plant Protection Organisations to develop standards that protect the post-treatment phytosanitary security of individual consignments.

Efficacy of quarantine treatments using reduced methyl bromide concentrations to disinfest Pinus radiata logs from New Zealand

We report here the results of three successive toxicity studies against a selection of forest insect pests, conducted in New Zealand to determine the efficacy of reduced methyl bromide (MB) rates, i.e. rates lower than those currently used, to disinfest export pine logs. First, the relative tolerance to MB among the naked life stages of the golden-haired bark beetle, Hylurgus ligniperda, the black pine bark beetle, Hylastes ater (Coleoptera: Curculionidae) and burnt pine longhorn beetle, Arhopalus ferus (Coleoptera: Cerambycidae) was determined in the laboratory. Then, the most MB-tolerant species and life stage(s) in pine logs was subjected to selected fumigation schedules using reduced concentrations of MB. Finally, the results of the laboratory studies were validated under commercial conditions at the Port of Tauranga, New Zealand, using logs infested with the most tolerant life stage, and log stacks. Our results indicated that either 30 g/m3 MB at >15 °C or 40 g/m3 MB at ≤ 15 °C for 16 h would ensure quarantine security against forest insects in New Zealand export logs. These reduced MB concentrations are approximately 70% and 65%, respectively, lower than 80 g/m3 at >15 °C or 120 g/m3 at ≤15 °C. If implemented by regulatory agencies and accepted by trading partners, these concentrations will provide significant environmental and economic benefits to the New Zealand forest industry and will pave the way for other countries to implement similar approaches to reduce MB usage in accordance to the Montreal Protocol.

Laboratory toxicity and large-scale commercial validation of the efficacy of ethanedinitrile, a potential alternative fumigant to methyl bromide, to disinfest New Zealand Pinus radiata export logs

We tested the efficacy of ethanedinitrile (EDN), a new fumigant considered as a potential methyl bromide (MB) replacement for the quarantine treatment of New Zealand pine, Pinus radiata D. Don, export logs. Firstly, toxicity trials were conducted in the laboratory with pine logs infested with the larvae, pupae, or adults of pine bark beetles, Hylurgus ligniperda and Hylastes ater, at 10 and 20 °C in 28-L chambers, to identify the most tolerant species and life stages. Then, logs infested with the most tolerant species and life stage were fumigated in 500-L laboratory chambers to determine whether the increase in the volume of the fumigated space and logs that will occur when scaling up from laboratory to commercial fumigations would affect EDN efficacy. Finally, confirmatory fumigation trials using commercial or semi-commercial sized log stacks, were conducted in a deforested commercial plantation area in Tokoroa, New Zealand, to demonstrate the efficacy of EDN in the field.Our results suggest EDN could be an effective alternative fumigant to MB for the phytosanitary treatment of logs exported from New Zealand. A phytosanitary fumigation schedule with EDN for P. radiata export logs that uses a concentration of 100 g/m3 for 20 h across a range of temperatures from 10 to 20 °C is recommended. Future efforts should focus on implementing the recommended schedule, under commercial practices, to provide quarantine security for export logs using EDN as a replacement for MB.

A first worldwide multispecies survey of invasive Mediterranean pine bark beetles (Coleoptera: Curculionidae, Scolytinae)

Several European and Mediterranean species of pine bark beetles (Coleoptera: Curculionidae: Scolytinae) have become established in North America and the southern hemisphere, posing a novel threat to planted and naturally-occurring pine forests. Our objectives were to investigate (1) the occurrence and relative abundance of pine bark beetles in these regions, and (2) the trapping performance of different blends of multispecies lures. In 2016–2017 a network of interception traps was installed in six non-European countries (Argentina, Australia, New Zealand, South Africa, the United States, and Uruguay), and in six European countries (France, Greece, Hungary, Italy, Portugal, and Spain) for comparison. Half of the traps were baited with alpha-pinene and ethanol, and the other half with alpha-pinene, ethanol, and a combination of bark beetle pheromones (ipsdienol, ipsenol, and Z-verbenol). Five Mediterranean scolytine species (Hylurgus ligniperda, Hylastes ater, H. angustatus, Orthotomicus erosus, and O. laricis) were found in non-European countries. Hylurgus ligniperda and Hylastes ater were the most widespread species found in several of the invaded regions, while O. laricis and H. angustatus occurred only in Argentina and South Africa, respectively. Despite large variation among species and countries, most species were trapped with the blend containing bark beetle pheromones, except O. erosus, which was more attracted to alpha-pinene and ethanol alone. This study represents the first step towards the development of an international monitoring protocol based on multi-lure traps for the survey and early-interception of invasive alien bark beetle species.

Ophiostomatoid fungi isolated from three different pine species in Argentinian Patagonia

SummaryPine plantations in Argentinian Patagonia cover ca. 95,000 ha in Chubut, Río Negro and Neuquén provinces. Exotic bark beetles (Orthotomicus laricis, Hylastes ater and Hylurgus ligniperda) commonly occur in freshly cut logs, stumps and slash. These beetles are vectors of “ophiostomatoid” fungi which include primary tree pathogens as well as important agents of blue stain. The aim of this study was to identify these beetle‐associated fungi. Sawing mills and pine plantations were surveyed three consecutive years. Fungal isolates from stained logs, processed wood and insect galleries were identified based on morphological and DNA sequence comparisons of ITS and β‐tubulin gene regions. Two Grosmannia, one Graphilbum and three Ophiostoma species were identified. Ophiostoma piliferum and O. peregrinum sp. nov. were the most frequently isolated taxa. O. peregrinum occurred in all provinces, colonizing different conifer species and, interestingly, also the native broadleaved species Nothofagus dombeyi. Pine plantation forestry in southern South America includes Argentina, Brazil, Chile, Paraguay and Uruguay. Emerging data from Argentina, Chile and Uruguay revealed some coincidences between these countries, but also several differences, probably, as a result of multiple introduction events.

Predicting forest insect flight activity: A Bayesian network approach.

Daily flight activity patterns of forest insects are influenced by temporal and meteorological conditions. Temperature and time of day are frequently cited as key drivers of activity; however, complex interactions between multiple contributing factors have also been proposed. Here, we report individual Bayesian network models to assess the probability of flight activity of three exotic insects, Hylurgus ligniperda, Hylastes ater, and Arhopalus ferus in a managed plantation forest context. Models were built from 7,144 individual hours of insect sampling, temperature, wind speed, relative humidity, photon flux density, and temporal data. Discretized meteorological and temporal variables were used to build naïve Bayes tree augmented networks. Calibration results suggested that the H. ater and A. ferus Bayesian network models had the best fit for low Type I and overall errors, and H. ligniperda had the best fit for low Type II errors. Maximum hourly temperature and time since sunrise had the largest influence on H. ligniperda flight activity predictions, whereas time of day and year had the greatest influence on H. ater and A. ferus activity. Type II model errors for the prediction of no flight activity is improved by increasing the model’s predictive threshold. Improvements in model performance can be made by further sampling, increasing the sensitivity of the flight intercept traps, and replicating sampling in other regions. Predicting insect flight informs an assessment of the potential phytosanitary risks of wood exports. Quantifying this risk allows mitigation treatments to be targeted to prevent the spread of invasive species via international trade pathways.

Use of shelterbelt pine trees as ‘stepping stones’ by Hylastes ater in agricultural landscapes

ABSTRACTHylastes ater and Hylurgus ligniperda, two exotic pine bark beetles in New Zealand, have recently been collected at locations far from pine plantations or other dead pine host material. We investigated if dispersing beetles are reproducing in the roots and root collars of damaged pine trees of shelterbelts (windbreaks) that are common in New Zealand’s agricultural landscapes. The ability of these bark beetles to breed in roots and root collars has been noted previously, primarily on dead trees and stumps. But to our knowledge it has not been empirically studied in New Zealand if roots of standing but physiologically declining (i.e. dying) trees can serve as suitable breeding material. We used a novel and effective root herbivore emergence trap, which is described here, to carry out this study. A total of 37 H. ater were captured across 13 traps and three sites in inland Canterbury; however, no H. ligniperda were found. We confirm that H. ater is able to colonise roots of damaged and declining isolated pine trees and show that shelterbelts can act as ‘stepping stones’ aiding spread and persistence through the landscape.

‘Unestablished’ biological control agent found in Canterbury 40 years later

ABSTRACTThe polyphagous ectoparasitoid, Rhopalicus tutela (Walker), introduced to New Zealand as a biological control agent of Hylastes ater (Paykull) during the 1970s, has recently been collected from a forest park in Canterbury. Researchers previously thought that the species had failed to establish at release sites around the North Island. Monitoring of the species was ceased in 1985 and research into its potential to control bark beetle populations was abandoned. Mystery surrounds whether the discovered population is part of the original introduction or may have arrived to New Zealand on its own.

Long‐distance dispersal of non‐native pine bark beetles from host resources

1. Dispersal and host detection are behaviours promoting the spread of invading populations in a landscape matrix. In fragmented landscapes, the spatial arrangement of habitat structure affects the dispersal success of organisms.2. The aim of the present study was to determine the long distance dispersal capabilities of two non‐native pine bark beetles (Hylurgus ligniperda and Hylastes ater) in a modified and fragmented landscape with non‐native pine trees. The role of pine density in relation to the abundance of dispersing beetles was also investigated.3. This study took place in the Southern Alps, New Zealand. A network of insect panel traps was installed in remote valleys at known distances from pine resources (plantations or windbreaks). Beetle abundance was compared with spatially weighted estimates of nearby pine plantations and pine windbreaks.4. Both beetles were found ≥25 km from the nearest host patch, indicating strong dispersal and host detection capabilities. Small pine patches appear to serve as stepping stones, promoting spread through the landscape. Hylurgus ligniperda (F.) abundance had a strong inverse association with pine plantations and windbreaks, whereas H. ater abundance was not correlated with distance to pine plantations but positively correlated with distance to pine windbreaks, probably reflecting differences in biology and niche preferences. Host availability and dispersed beetle abundance are the proposed limiting factors impeding the spread of these beetles.5. These mechanistic insights into the spread and persistence of H. ater and H. ligniperda in a fragmented landscape provide ecologists and land managers with a better understanding of factors leading to successful invasion events, particularly in relation to the importance of long‐distance dispersal ability and the distribution and size of host patches.

Olfactory Cues, Visual Cues, and Semiochemical Diversity Interact During Host Location by Invasive Forest Beetles

Plant-feeding insects use visual and olfactory cues (shape, color, plant volatiles) for host location, but the relative importance of different cues and interactions with non-host-plant volatiles in ecosystems of varying plant biodiversity is unclear for most species. We studied invasive bark beetles and wood borers associated with pine trees to characterize interactions among color, host and non-host volatiles, by employing traps that mimic tree trunks. Cross-vane flight intercept traps (black, green, red, white, yellow, clear) and black funnel traps were used with and without attractants (α-pinene + ethanol), repellents (non-host green leaf volatiles, 'GLV'), and attractant/repellent combinations in four pine forests in New Zealand. We trapped 274,594 Hylurgus ligniperda, 7842 Hylastes ater, and 16,301 Arhopalus ferus. Trap color, attractant, and color × attractant effects were highly significant. Overall, black and red traps had the highest catches, irrespective of the presence of attractants. Alpha-pinene plus ethanol increased trap catch of H. ligniperda 200-fold but only 6-fold for H. ater and 2-fold for A. ferus. Green leaf volatiles had a substantial repellent effect on trap catch of H. ligniperda but less on H. ater and A. ferus. Attack by H. ligniperda was halved when logs were treated with GLV, and a similar effect was observed when logs were placed among broadleaved understory shrubs emitting GLV. Overall, H. ligniperda was most strongly affected by the olfactory cues used, whereas H. ater and A. ferus were more strongly affected by visual cues. Collectively, the results support the semiochemical diversity hypothesis, indicating that non-host plant volatiles from diverse plant communities or artificial dispensers can contribute to resistance against herbivores by partly disrupting host location.

Effects of elevation and aspect on the flight activity of two alien pine bark beetles (Coleoptera: Curculionidae, Scolytinae) in recently-harvested pine forests

Climate is an important driver of the establishment and impact of invasive alien species. Species transported to new regions can only invade those with a climate that meets their thermal requirements, but climate change is likely to alter the invasibility of recipient environments. Likewise, species are unlikely to reach pest status where climatic conditions are suboptimal. Here our objectives were to determine the relationship between climatic conditions and flight activity of two alien pine bark beetles (Hylastes ater and Hylurgus ligniperda) and to anticipate how climate change may affect the future distribution of these species. We used elevational gradients and slope aspect (north versus south-facing slopes), which are known to affect microclimates, to assess the effects on beetle flight across 18 locations in pine forests in the South Island, New Zealand. Using panel traps baited with alpha-pinene and ethanol we caught a total of 45,363 H. ligniperda and 6676 H. ater. Catches of both species decreased significantly and substantially with increasing elevation. Significantly more beetles were caught at north-facing than at south-facing sites towards the end of the flight season in autumn, leading to an extended flight period at northerly aspects. These results are important for pest management and the identification of ‘areas of low pest prevalence’ as a measure to reduce post-harvest infestations of logs destined for export. For example, during risk periods, logs could be harvested preferentially from stands with reduced flight activity (i.e., southerly aspects and higher elevations). Furthermore, such sites could be chosen to reduce post-harvest infestation risks during periods of temporary log storage at skid sites in the forest. Our findings are also important because climate change can be an important factor contributing to population expansion of bark beetles, and warmer temperatures could lead to increased flight activity and abundance, as well as enhanced suitability of sites that are currently less favourable.

Metabarcoding of fungal communities associated with bark beetles.

Many species of fungi are closely allied with bark beetles, including many tree pathogens, but their species richness and patterns of distribution remain largely unknown. We established a protocol for metabarcoding of fungal communities directly from total genomic DNA extracted from individual beetles, showing that the ITS3/4 primer pair selectively amplifies the fungal ITS. Using three specimens of bark beetle from different species, we assess the fungal diversity associated with these specimens and the repeatability of these estimates in PCRs conducted with different primer tags. The combined replicates produced 727 fungal Operational Taxonomic Units (OTUs) for the specimen of Hylastes ater, 435 OTUs for Tomicus piniperda, and 294 OTUs for Trypodendron lineatum, while individual PCR reactions produced on average only 229, 54, and 31 OTUs for the three specimens, respectively. Yet, communities from PCR replicates were very similar in pairwise comparisons, in particular when considering species abundance, but differed greatly among the three beetle specimens. Different primer tags or the inclusion of amplicons in separate libraries did not impact the species composition. The ITS2 sequences were identified with the Lowest Common Ancestor approach and correspond to diverse lineages of fungi, including Ophiostomaceae and Leotiomycetes widely found to be tree pathogens. We conclude that Illumina MiSeq metabarcoding reliably captures fungal diversity associated with bark beetles, although numerous PCR replicates are recommended for an exhaustive sample. Direct PCR from beetle DNA extractions provides a rapid method for future surveys of fungal species diversity and their associations with bark beetles and environmental variables.

Listening to the hidden sounds in the forest

Many bark beetles (Coleoptera Curculionidae Scolytinae) exhibit a wide array of acoustic abilities including sounds used in mate attraction territoriality and defence In New Zealand the goldenhaired bark beetle Hylurgus ligniperda and the black pine bark beetle Hylastes ater are two species of forest insects which may be found on export logs Acoustic signals have been shown to discourage a related bark beetle the western pine beetle Dendroctonus from entering into pine logs and to disrupt mating and tunnelling These recent studies combined with observations of H ligniperda and H ater helped to establish the concept that acoustic disruption could be used as part of a wider systems approach to deter these beetle species near saw mills skid sites and ports If proven effective this technique would add value to New Zealand log exports and decrease the reliance on toxic fumigants as the primary control measure This study shows some of the functions and physical characteristics of the acoustic signals produced by H ligniperda and H ater