Hylotrupes Research Articles

Monoterpenes profile and high temperature as a potential factors in the infestation of wooden structures by Hylotrupes bajulus L

Hylotrupes bajulus L. is a dangerous destroyer of wooden structures. Monoterpenes (mainly α-pinene and 3-carene) attract of this beetle females to lay eggs on wood. The phenomenon of sporadic occurrence of old house borer larvae in old wooden structures and its reappearance in these structures after the previous use of hot air to old house borer combating has been known for many decades. The causes of these phenomena were not explained. In this work, it was hypothesized that the cause of these phenomena was poor attraction of this wood for females due to the reduced amount of monoterpenes in such wood. An experiment was carried out on the possibility of developing old house borer larvae in old natural aged wood. Tests were also carried out on the profile of monoterpenes in uninfested old natural aged wood, contemporary wood and contemporary wood after heating at high temperature. The possibility of development of newly hatched H. bajulus larvae in old natural aged wood and a high concentration of monoterpenes (mainly α-pinene and 3-carene) in such wood were found. The sporadic presence of old house borer larvae in very old wooden structures cannot be explained directly by a reduction in the concentration of attracting monoterpenes. The concentration of monoterpenes in contemporary wood after exposure to high temperature was whereas significantly reduced. This may be the reason for sporadic cases of repeated attacks on structures previously exposed to very hot air.

Protective role of DTPA against Hylotrupes bajulus L. infestations by targeting metal ion incorporation in larval mandibles

The house longhorn beetle, Hylotrupes bajulus L., is a recognized wood pest with larvae capable of infesting and damaging various wood species. The larvae’s wood-cutting capability is attributed to the metal-reinforced chitin in their mandibles, which provides enhanced mechanical strength. This reinforcement is due to the presence of metal ions such as zinc (Zn) and manganese (Mn) bound to the chitin structure. The present study investigates the potential of diethylenetriaminepentaacetic acid (DTPA), a chelating agent, to sequester these crucial metal ions thereby affecting the larvae’s feeding capability. Wood samples treated with varying doses of DTPA showed significant larval mortality, with a 100% rate at a dose of 6 g/l. Electron microscopic analyses of deceased larvae revealed an absence of Zn in their mandibles, suggesting that DTPA effectively reduces its bioavailability, hindering mandible strengthening. The toxicity profile of DTPA is lower compared to many traditional wood treatments, indicating a potential for reduced environmental impact. However, the full spectrum of DTPA’s preservation capabilities and its interactions with other organisms require further investigation.

Assessment of the ability for early detection of newly hatched larvae of Hylotrupes bajulus L. using the acoustic emission method in Scots pine wood

The acoustic emission analysis method was used to determine the activity of very young Hylotrupes bajulus larvae in their long-term development. In the laboratory conditions the simulated scenario of a fresh, intense infestation inside the construction wood was evaluated. The sounds generated by the insects during their feeding on the wooden samples were processed by the measurement system, which was able to detect and count the larva-originated sound pulses and calculate related energy. So far, no one has examined possibilities of detecting infant larvae of Hylotrupes bajulus L. This work is a continuation of research on the influence of the insect mass on its AE-based detection. The experiments performed with multiple wood samples analyzed through the period of one year have shown dependency between the mass of the larva and the intensity of the sound generated by them. The moment of the earliest possible detection of infestation in the wooden structure was evaluated. In the appropriate conditions (large number of young larvae inside the wood and optimal temperature) the insects reach the mass of tens of mg, which makes them detectable using the AE method.

Acoustic detection and localisation system for Hylotrupes bajulus L. larvae using a MEMS microphone array

A novel system for acoustic detection of the presence of xylophagous insect larvae inside structural timber beams is presented. It is based on an extensive array of MEMS microphones that allows the acoustic detection and localisation of the larvae when they are active. In a first phase, the activity of the larvae is continuously detected by means of frequency filtering and a sliding energy estimator, and after that, a set of short-duration segmented signals is generated, which obtains the spatial localisation of the larvae, by means of a shaping algorithm based on delay-sum beamforming techniques.The tests carried out demonstrate that it is possible to detect and locate multiple larvae of Hylotrupes bajulus L. inside structural-sized pieces of wood of Pinus syilvestris L., as well as their internal trajectory.In the future, the system could address the identification of the specific type of xylophage responsible for the deterioration by using machine learning or equivalent techniques, based on the temporal and frequency information of the detected sound events.The aim of this work is to control unintentional infestions in the international timber trade, in the assembly and the use of infested timber and, in all cases, to be able to carry out selective, targeted and localised treatments and to verify their success.

Antifungal and larvicidal effects of wood vinegar on wood-destroying fungi and insects

Wood vinegar is a natural organic pesticide that is effective against plant diseases and harmful insects and is used in agriculture in particular for the improvement of plant and soil quality.In different application areas, wood vinegar provides effective protection against various harmful bacteria, fungi, and insects.Based on its demonstrated protection as a pesticide and antifungal, this study aimed to use wood vinegar as an impregnation agent in wood materials. For this purpose, using the full-cell process, Pinus sylvestris and Fagus orientalis samples were impregnated with concentrations of 1 %, 5 %, 3 % and 6% oak wood vinegar, obtained via the pyrolysis of sessile Quercus petraea. wood at 350 °C.The samples were then subjected to tests for brown-rot (Serpula lacrymans) and white-rot (Trametes versicolor) fungi, for Hylotrupes bajulus (Coleoptera: Cerambycidae) larvae, and for three different mold fungi (Aspergillus niger Tiegh JAG-04-1003, Penicillium brevicompactum Dierckx FS-31, and Trichoderma harzianum Rifai FS-19). According to the results, the wood vinegar was found to exhibit antifungal, antimold, and larvicidal properties and consequently, could be used effectively in wood protection.

Detection of old house borer larvae in wooden structures by acoustic emission method – Influence of larval size and sensor location

The detection of old house borer larvae (Hylotrupes bajulus L.) in Scots pine wood (Pinus sylvestris L.) was performed using the acoustic emission (AE) method. Laboratory experiments (as preliminary) as well as real tests in full-sized building elements were performed. The sound energy of larvae with a mass of 0.011 g to 0.065 g placed in small samples of wood was calculated. A remarkable relationship was found between the calculated sound energy and larva mass. The AE measurement of an old house borer larva in construction element with a cross-section of 11.0 cm × 5.5 cm and a length of 203 cm was also performed. A remarkable drop in calculated sound energy was observed with increasing distance of the sensor from the larval presence. Similar measurements were also conducted in wood with a cross-section of 1.5 cm × 1.5 cm and a length of 203 cm. There was a smaller decline in the calculated energy of sound than in previous studies. For this reason, the AE method should be used in detecting wood-boring insects in furniture.

Bio-Based Phase Change Materials for Wooden Building Applications

Solid wood can serve multifunctionality for energy savings in buildings. The study reveals the results of biodeterioration and degradation of solid Scots pine wood used to incorporate single or multicomponent fatty acid mixtures as bio-based phase change materials (BPCMs). The sapwood samples were impregnated with capric acid (CA), methyl palmitate (MP), lauryl alcohol (LA) and a mixture of coconut oil fatty acids and linoleic acid (CoFA-LA). The samples were tested against subterranean termites by an Italian species (Reticulitermes lucifugus), the wood boring beetle Hylotrupes bajulus and mold through a discoloration test. Tested against termites, the impregnated samples were significantly less susceptible to the attack than the controls, i.e., the tested BPCMs were resistant to R. lucifugus. The only test with MP terminated at the moment against H. bajulus showed positive results with no larvae surviving. The mold discoloration test revealed that the wood impregnated with CoFA-LA was identically susceptible to mold discoloration when compared to the control, nonimpregnated samples. This pioneer study verifies that solid wood employed for the encapsulation of BPCMs for building purposes can serve identically or somewhat better than similar wooden building elements regarding attacks of the above microorganisms and insects. Such multifunctional building elements will be tested further in a pilot scale building to characterize better the durability aspects of the new materials.

Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass.

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of wood-based structures in a layer wise fashion using the Binder Jetting printing process. The quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a Hausner Ratio HR = 1.1 with ρBulk = 0.67 g/cm3 and ρTap = 0.74 g/cm3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing.

Morphological and chemical analysis of Hylotrupes bajulus (old house borer) larvae-damaged wood and its FTIR characterization

In this study, the biodegradation of wood and chemical changes caused by the Hylotrupes bajulus beetle were revealed for the first time using FTIR spectroscopy. In the study, Scots pine (Pinus sylvestris), fir (Abies nordmanniana), and spruce (Picea orientalis) wood species were exposed to damage by H. bajulus larvae for four months. Morphological measurements and chemical analysis were carried out for the fine powdery dust (FPD) and frass (FR) produced by H. bajulus and compared to control samples. In addition, the FPD and FR of the larvae were examined by FTIR analysis and changes in the wood structure were determined. According to the morphological measurement data obtained from the study, the dimensions of the larval FR were 1 × 0.55 mm screened at 20-mesh, and 0.37 × 0.24 mm at 60-mesh. Holocellulose analysis showed that less holocellulose was detected in the FR and FPD than in the control wood. In the sugar analysis performed via HPLC, the glucose, xylose, galactose, mannose, and arabinose components decreased compared to the control wood, whereas the content of acid-insoluble lignin increased. The FTIR spectra of the wood species (especially in Scots pine) showed that the carbohydrate band intensity at 1735, 1370, 1321, and 897 cm−1 decreased and the carbohydrate bands at 1735, 1321, 1369, and 897 cm−1 were nearly absent in the FPD and FR after H. bajulus larva degradation. However, absorption band intensity at 1508, 1458, 1268, and 1031 cm−1 related to the lignin bands increased significantly. According to these results, H. bajulus larvae degraded cellulose and hemicellulose from the wood components, but they did not degrade lignin.

Determination of decay, larvae resistance, water uptake, color, and hardness properties of wood impregnated with honeybee wax

The aim of the study was to determine the effect of honeybee wax impregnation on the antifungal, larvicidal, water uptake, color, and mechanical properties of wood. Wood samples (poplar, Scots pine, beech, and lime) were impregnated with melted honeybee wax under vacuum. The wax-impregnated samples were exposed to the wood-decay fungi Trametes versicolor and Neolentinus lepideus for 8 weeks. The larvicidal effect of the beeswax was tested against European old house borer (Hylotrupes bajulus L.). Water uptake, color measurements, and surface hardness were also tested. According to the obtained findings, a 34.6% mass loss was seen in the poplar control wood, and only 3.9% mass loss was found in the 100% beeswax-impregnated samples. The results showed that H. bajulus larvae could digest honeybee wax with wood when beeswax surface treatment was applied. Additionally, an average of 30% larvae mortality rate was achieved on beeswax-treated wood surfaces, compared to a 2.5% rate on the controls. However, when wood was deeply treated with beeswax, larval mortality reached 100%. In the water uptake test, beeswax-treated samples showed water repellent efficiency. The lowest water uptake (24.2%) was obtained in poplar wood treated with 100% beeswax, compared to 92.6% in the poplar control in 96 h immersion time. With the beeswax treatment, a* and b* color values increased, while the L* values decreased.

Decay, insect, and termite resistance of wood modified with epoxidized vegetable oils

Abstract Samples of Scots pine sapwood were treated with epoxidized linseed and soybean oils to improve decay, insect and termite resistance of wood. Non-epoxidized (raw) linseed and soybean oils were included as reference treatment in the study. In the epoxidation process, hydrogen peroxide was used to open double bounds, and acetic acid was added as a catalyst. Two retention levels, Ret A (80–140 kg m−3) and Ret B (170–270 kg m−3), two impregnation methods (full cell and empty cell) and emulsion technique were used. Samples treated with epoxidized oils had significantly lower mass losses than untreated samples while epoxidized oils showed higher mass losses than unepoxidized oils for Coniophora puteana and Trametes versicolor according to EN 113 for decay test. By adding boron, fungicidal properties were introduced to the treatment. All the vegetable oils showed 100% the mortality rate against larvae of Hylotrupes bajulus according to EN 47. Moreover, leached wood samples treated with oils also showed 100% larvae mortality. Additionally, termite testing based on EN 117 revealed 100% Reticulitermes lucifugus mortality for all leached oil treated samples.

Damage severity of wood-destroying insects according to the Bevan damage classification system in log depots of Northwest Turkey

The aim of the study was to determine damage severity of wood-destroying insects on logs stored in forest depots. The Bevan damage classification (BDC) system, developed in 1987, was utilized to determine damage severity in log depots in 21 locations throughout seven provinces in Turkey. Pheromone traps were placed in those locations at the beginning of April in 2015 and 2016. Furthermore some stored wood within the log depots were checked and split into small pieces to collect insects that damage wood. The BDC system was used for the first time to measure the severity of insect damage in log depots. Twenty-eight families, 104 genera and 123 species were identified in this study. Based on the BDC system, the highest damage was found from the Cerambycidae and Buprestidae families. Arhopalus rusticus was determined as the insect responsible for the highest amount of damage with 8.8% severity rating in the pheromone-trapped insects group. When the stored wood material was considered, Hylotrupes bajulus was found to be the cause of the highest damage. The lowest damage values were among the predator insects (Cleridae, Trogossitidae, Cantharidae) and those feeding on fungi colonized on the wood (Mordellidae, Cerylonidae, Nitidulidae). Some other predator insects of the Tenebrionidae family (Uloma cypraea, Uloma culinaris, Menephilus cylindricus) and Elateridae family (Lacon punctatus, Ampedus sp.) exhibited relatively higher damage severity values since they had built tunnels and made holes in the stored wood material. When the environmental factors were considered, the Buprestidae family exhibited a very strong positive relationship (p < 0.005) with insect frequency distribution (r = 0.922), number of species (r = 0.879) and insect density (r = 0.942). Both families showed the highest number and frequency during July and August, highlighting the importance of insect control and management during these months.

Transportation of Wood Boring Beetles in Wooden Transport Boxes, Wooden Pallets, and Newly Bought Wood in Museums

ABSTRACT In the past, woodborers like A. punctatum and X. rufovillosum were widespread in historic furniture, households, and building structures, but as they need a high wood moisture content and central heating and climate control have become common today their occurrence is rare and often limited to open-air museums, rural museums, and historic buildings. In this paper, we report on the spread and transportation of different wood-boring beetles with wooden pallets, wooden transport boxes used for art transportation, and also the rising problem of different Lyctus species (powder post beetles) in new wood used in museums. Not only the native Lyctus linearis but also the introduced L. brunneus, L. cavicollis, and L. africanus can be found in transport boxes (nine cases in Germany between 2003 and 2015), infestations of new picture frames (three cases in Austria between 2010 and 2015), and new wood sold to carpenters in museum and conservation studios (used for new stretcher and picture frames, two cases in Austria). In some cases (two in Germany) a newly-laid parquet floor was infested by powder post beetles. The house longhorn beetle (H. bajulus), the furniture beetle (A. punctatum), and the Anobiid Oligomerus ptilinoides were all found infesting wooden pallets inside museum stores (five cases in Austria). New wooden pallets and transport boxes are treated once with heat after production, but our examples show that infestation and transportation of wood pests are still possible and are a new challenge for integrated pest management (IPM) in the future. We examine and discuss the materials used to transport art and possible measures to combat and prevent pests (plastic pallets or the use of other wood types). In addition, the biology and life-history of powderpost beetles is described.

The progress in the research of AE detection method of old house borer larvae (Hylotrupes bajulus L.) in wooden structures

The paper presents the automated analysis of the presence of the old house borer larvae (Hylotrupes bajulus L.) in the wooden constructions. The insect activity was observed in a temperature of 28, 30, 32, 34, 36, 38 and 40 °C in a Scotch pine wood j (Pinus sylvestris L.). That activity has been evaluated by 3 criteria: the number of 5-minute periods with the presence of larvae boring wood sounds confirmed, the number of wood bites and the average sound energy during the larva's wood carving. The comparable results showing larvae change in activity have been achieved using these 3 methods. This approach has proved high efficiency of old house borer larvae detection in the temperatures up to 34 °C, nevertheless for temperatures exceeding 40 °C it is not applicable. The exposure to 40 °C for a week did not cause the death of large larvae. It's highly possible that they can return to a wood carving after the detracting factor has ceased. The sound energy produced during the old house borer larvae's wood-drilling is expected to make the AE method useful for detection of old house borer larvae's in large-size constructions.

The effect of particle board industry waste tar on the physical and biological durability of wood

The effect of waste tar from particle board factories was investigated relative to some physical and biological resistance properties of Scots pine (Pinus sylvestris) and beech (Fagus orientalis) woods. Solutions were prepared by dissolving waste tar in ethanol:toluene (1v:1v) in concentrations of 5%, 10%, 15%, and 20%. These solutions were forced deep into the Scots pine and beech woods under vacuum and pressure (deep treatment, DT). In addition, surface coating (SC) was applied by spreading 96% waste tar on the wood surfaces after treatment. Deep-treated and surface-coated (DT+SC) wood samples were exposed to the wood-decay fungi Trametes versicolor L. and Neolentinus lepideus Fr. for 12 weeks. At the same time, sample blocks were tested against wood-destroying house borer (Hylotrupes bajulus) larvae for 16 weeks. Total phenolic content, water uptake, water-repellent efficiency, and surface contact angle were tested. Although a mean mass loss resulting from T. versicolor of 31.1% was seen in the Scots pine control samples, only 3.87% mass loss was found with a concentration of 20% (DT + SC). The H. bajulus larvae mortality rate was 80% in the Scots pine wood samples deep-treated with 20% waste tar.

Mold and larvae resistance of wood-based composites incorporating sodium fluoride

The efficacy of particleboards manufactured with sodium fluoride against mold fungi and Hylotrupes bajulus (L.) larvae was tested. Laboratory-size particleboards were manufactured from untreated wood particles with inclusion of fine sodium fluoride (NaF) at the 1, 1.5, and 3% levels relative to total particle weight. Sodium fluoride was introduced as powder during the manufacturing process just before blending resin with wood particles. The laboratory mold test indicated that even the lowest level of retention of NaF with or without leaching significantly reduced mold growth on particleboard surfaces when compared to the untreated control specimens. The increased retention of NaF from 1% to 3% further suppressed mold growth towards lowest levels even on leached specimens. The laboratory Hylotrupes bajulus larvae tests revealed that the particleboard environment with or without NaF is not appropriate for larvacidial activity. While the tested biocide, NaF, tested positive against mold growth on particleboard surfaces, no effect was determined relative to larval deaths.

Physical, biological and chemical characterisation of wood treated with silver nanoparticles

Nowadays, environmentally friendly processes are of great interest and are considerably needed due to the environmental pollution seems to be a problem worldwide. For this reason, in this study, silver nanoparticles were synthesized using environmentally-friendly methods and their effectiveness as wood preservatives was investigated. Scots pine (Pinus sylvestris L.) samples were impregnated with an autoxidized soybean oil polymer containing Ag nanoparticles (Agsbox). Samples characterised by Fourier transform infrared spectroscopy (FTIR) were tested against brown rot (Coniophora puteana) and wood-destroying insects (Hylotrupes bajulus). In addition, decay tests were applied to mini-block samples leached according to the EN 84 standard. Results demonstrated that Agsbox increased decay resistance in the unleached samples. However, low efficacy was exhibited against newborn H. bajulus larvae. As a results of FTIR measurement, impregnated with the nanocomposites showed significant changes at the 2910 cm−1 (C–H) and 1712 cm−1 (C=O) peaks.

Investigation of natural durability of some native and exotic wood species against Hylotrupes bajulus (Cerambycidae) and Anobium punctatum (Anobiidae)

Aim of study: In this study, natural durability of some domestic and foreign wood species against Hylotrupes bajulus and Anobium punctatum larvae were tested on laboratory scaleArea of study: This study was conducted at Department of Forest Products Engineering in Duzce University, Turkey and Federal Institute for Materials Research and Testing (BAM), Germany.Material and Methods: Scotch pine (Pinus sylvestris), fir (Abies nordmanniana), spruce (Picea orientalis), cedar (Cedrus libani), poplar (Populus tremula) and beech (Fagus orientalis) woods were used to test H. bajulus larvae (EN 46-1). Alder (Alnus glutinosa), oak (Quercus cerris), poplar (Populus tremula), beech (Fagus orientalis), maple (Acer carpinifolium), ash (Fraxinus angustifolia), teak (Tectona grandis), ayous (Triplochiton scleroxylon), movingui (Distemonanthus benthamianus), dahoma (Piptadeniastrum africanum), iroko (Chlorophora excelsa), bubinga (Guibourtia tessmannii) and sapele (Entandrophragma cylindiricum) woods were used for A. punctatum larvae (EN 49-1). At the end of the experiment, the mortality rates of the larvae were determined and the size and weights of the surviving larvae were measured.Main results: F. orientalis and C. libani were found to be the most resistant wood species against H. bajulus larvae while A. nordmanniana was the least resistant. All tropical wood species and oak and maple from domestic wood species showed 100% mortality rate therefore found to be the most resistant against A. punctatum larvae. The most vulnerable wood species was found to be alder with a 35% mortality. Research highlights: while F. orientalis, C. libani, and P. tremula were found the most resistance wood species against H. bajulus, P. sylvestris and A. nordmanniana were determined as most vulnerable. All tropical wood species and two domestic species (Q. cerris and A. carpinifolium) showed the highest mortality rate as 100%. The least durable domestic wood was determined as alder.

Chemical‐Free Pest Control by Dielectric Heating with Radio Waves and Microwaves: Thermal Effects

AbstractThermal pest control with hot air is widely accepted as an alternative to chemical methods. However, it requires relatively long treatment times owing to the low thermal conductivity of wood. Direct dielectric heating that applies radio waves or microwaves has the advantage of more homogeneous heating. However, sound experimental data on this technique are currently rare. Therefore, the thermal treatment of wood‐destroying insects with radio waves and microwaves was studied with two model pests, Anobium punctatum and Hylotrupes bajulus, and with Tenebrio molitor as a reference. The secure elimination of pests was achieved, and the corresponding treatment time was in the range of a few minutes. Temperature profiles were more homogeneous when applying radio waves.

THE RELATIONSHIP BETWEEN THE MASS OF OLD HOUSE BORER LARVAE HYLOTRUPES BAJULUS (L.) AND THEIR LENGTHS MEASURED USING RADIOGRAPH

THE RELATIONSHIP BETWEEN THE MASS OF OLD HOUSE BORER LARVAE HYLOTRUPES BAJULUS (L.) AND THEIR LENGTHS MEASURED USING RADIOGRAPH