Search Results (24)

Background: Pinus massoniana is a significant lipid-producing tree species in China and a susceptible host for both the pine wood nematode and its insect vector, Monochamus alternatus. The basic helix–loop–helix (bHLH) family of transcription factors play a crucial role in responding to both biotic and abiotic stresses. However, the role of bHLH in terpene-induced defense in P. massoniana remains poorly studied. Results: Transcriptome sequencing using DNA Nanoball Sequencing (DNBSEQ) and PacBio Sequel platforms was performed, revealing differences in gene expression in P. massoniana branch under the simulated feeding treatment of methyl jasmonate (MeJA) spraying. Fifteen bHLH genes were cloned and analyzed, among which eight highly upregulated PmbHLH genes showed similar temporal expression after MeJA treatment and M. alternatus adult feeding. Five highly upregulated bHLH genes with nuclear localization were highly expressed in P. massoniana after M. alternatus feeding and interacted with the promoter of the terpene synthase gene Pm TPS (−)-α-pinene, confirming their involvement in the defense response of P. massoniana against the M. alternatus adult feeding. Conclusions: Our results unveil the temporal changes and the regulation of the induced defense system in P. massoniana mediated by both MeJA signaling and M. alternatus feeding treatment. The potential application for transgenic experiments and the breeding of resistant species in the future were discussed. Full article

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies of trees lowers the frequency of defoliator outbreaks, as well as increases local biodiversity. Nearly half of their diverse diet is insects, including species considered harmful by foresters. They also have a mutualistic relation with honeydew-producing aphids and planthoppers, which connection has unclear effects on the forests. The habit of RWAs building nests could also positively influence soil composition, due to its structure and high amount of organic matter, which could potentially benefit tree growth. RWAs are also known to enhance the species richness of forests by supporting various myrmecophilous species associated with them. In this study, we review the role of RWAs in forest protection, drawing on the literature focusing on Hungary and Central Europe. Full article

Populus alba var. pyramidalis (PaP) is a very important and main planted tree species in northwestern China. However, it has been threatened by Asian longhorned beetle Anoplophora glabripennis (ALB) infestation. A feasible way to protect PaP is by improving its own insect resistance ability. In order to achieve this goal, we first checked whether ALB could induce the defense system of PaP by comparing the ALB-attracted volatiles of PaP before and after ALB infestation through the collection and identification of volatiles by gas chromatography–mass spectrometry (GC-MS). We found that attractant volatiles (Z)-3-hexenol (Z3H) and (Z)-3-hexen-1-yl acetate (Z3HA) decreased by 72.99% and 74.53% after ALB infestation, respectively. Then, the contents of the plant hormones salicylic acid (SA), jasmonic acid (JA), methyl salicylate (MeSA), and methyl jasmonate (MeJA) and the defense substances hydrogen peroxide (H₂O₂), peroxidase (POD), and total superoxide dismutase (T-SOD) in the phloem of PaP were determined before and after ALB infestation by high-performance liquid chromatography–mass spectrometry (HPLC-MS) and a manufacturer’s kit, respectively. The results showed that the quantities of SA decreased, but JA and MeJA increased by 2.1 times and 3.02 times, respectively, and the increase in H₂O₂ and POD was also significant. Therefore, we hypothesized that MeJA might be closely related to the induced ALB resistance of PaP. Further exogenous spraying of MeJA on PaP showed that the feeding and oviposition of ALB adults were significantly decreased on PaP, confirming that MeJA could improve PaP’s resistance against ALB. The concentration effect showed that 10⁻⁴ mol/L of MeJA treatment induced the strongest results. Our results clearly demonstrated the response of a poplar species to a wood borer infestation and provide an alternative method to protect PaP in the future. Full article

Cinnamomum camphora is a broad-spectrum insect-repelling tree species because of its high content of terpenoids. However, it is curious that Pagiophloeus tsushimanus, a recently recorded wood-boring pest, has widely infested C. camphora plantations across various administrative districts in Shanghai. The larvae, being concealed within the trunk of C. camphora trees, exhibit characteristics such as hidden activity, strong destructiveness, and being difficult to control. While the primary host plant for P. tsushimanus is C. camphora, preliminary observations have shown that the pest can also complete its life cycle on Cinnamomum chekiangensis and Phoebe chekiangensis. To explore the host selection preference of this beetle, the present study aimed to investigate the olfactory selection behavior of P. tsushimanus adults towards C. camphora, C. chekiangensis, and P. chekiangensis. Results from choice and no-choice tests indicated that both male and female adults exhibited a feeding preference for C. camphora twigs, with females showing a preference for laying eggs on camphor tree twigs as well. Volatile compounds unique in camphor trees were significantly higher in relative content than those on the other two plants that were detected. The Y-shaped olfactometer experiments and electroantennography measurements results showed that male and female adults of P. tsushimanus had a positive chemotaxis towards volatiles released by C. camphora and a negative chemotaxis towards volatiles released by C. chekiangensis or P. chekiangensis. Overall, the findings suggest that both male and female adults have a selective preference for volatiles released by the camphor tree, and this provides a theoretical basis for monitoring and controlling the occurrence of this weevil pest. Full article

In alpine environments, open habitats alternate with wood to create a habitat mosaic that shapes insect community composition and diversity. Dung beetles are an important group of insects specialized in feeding on vertebrate dung whose availability also depends on habitat type. Although the habitat preferences of dung beetles have been extensively studied, few studies have addressed the influence of habitat structure and temperature on dung beetle communities in alpine environments. We sampled dung beetles in pastures, at the edges between pasture and wood, in inner and outer woods of two alpine areas at different altitudes (two sites per area). We found that pastures had higher mean temperatures compared to other habitat types and hosted the highest number of species. However, the interaction between habitat and altitude significantly affected species richness and abundance, suggesting that habitat type and temperature modulate the response of dung beetles in the study area. Edges hosted intermediate communities between pastures and woodlands and were populated by both pasture and woodland specialists. Our results suggest that maintaining pastures is crucial to preserving dung beetle communities. Full article

As a new vector insect of pine wood nematodes in China, the Monochamus saltuarius (Coleoptera: Cerambycidae) vectors pine wilt nematodes into healthy pine trees through feeding and oviposition, resulting in huge economic losses to forestry. A promising control strategy is to develop safe and efficient attractants. This study aims to screen for the key active volatiles of Pinus koraiensis (Pinales: Pinaceae), Pinus tabuliformis (Pinales: Pinaceae), and Picea asperata (Pinales: Pinaceae) that can attract M. saltuarius, and to study the synergistic attraction of the main attractant plant volatiles with ethanol and insect aggregation pheromones. The preference of M. saltuarius for three hosts is P. koraiensis > P. tabuliformis > Picea asperata. We detected 18 organic volatiles from three host plants. Through EAG assays and indoor Y-tube behavioral experiments, 3-carene, (-)-camphor, β-pinene, α-phellandrene, terpinolene, α-pinene, D-limonene, and myrcene were screened to have attractive effects on M. saltuarius. We found that 3-carene, β-pinene, and α-pinene are the most attractive kairomones in field experiments, which may play a crucial role in the host localization of M. saltuarius. Ethanol has a synergistic effect on the attractant activity of 3-carene and β-pinene, and the synergistic effect on β-pinene is the best. The mixture of ethanol, 2-undecyloxy-1-ethanol, and ipsdienol can significantly enhance the attraction effect of β-pinene on M. saltuarius. These new findings provide a theoretical basis for the development of attractants for adult M. saltuarius and contribute to the green control of M. saltuarius. Full article

Wood borers, such as the emerald ash borer and holcocerus insularis staudinger, pose a significant threat to forest ecosystems, causing damage to trees and impacting biodiversity. This paper proposes a neural network for detecting and classifying wood borers based on their feeding vibration signals. We utilize piezoelectric ceramic sensors to collect drilling vibration signals and introduce a novel convolutional neural network (CNN) architecture named Residual Mixed Domain Attention Module Network (RMAMNet).The RMAMNet employs both channel-domain attention and time-domain attention mechanisms to enhance the network’s capability to learn meaningful features. The proposed system outperforms established networks, such as ResNet and VGG, achieving a recognition accuracy of 95.34% and an F1 score of 0.95. Our findings demonstrate that RMAMNet significantly improves the accuracy of wood borer classification, indicating its potential for effective pest monitoring and classification tasks. This study provides a new perspective and technical support for the automatic detection, classification, and early warning of wood-boring pests in forestry. Full article

Cockroaches of the subfamily Panesthiinae (family Blaberidae) are among the few major groups of insects feeding on decayed wood. Despite having independently evolved the ability to thrive on this recalcitrant and nitrogen-limited resource, they are among the least studied of all wood-feeding insect groups. In the pursuit of unraveling their unique digestive strategies, we explored cellulase and xylanase activity in the crop, midgut, and hindgut lumens of Panesthia angustipennis and Salganea taiwanensis. Employing Percoll density gradient centrifugation, we further fractionated luminal fluid to elucidate how the activities in the gut lumen are further partitioned. Our findings challenge conventional wisdom, underscoring the significant contribution of the hindgut, which accounts for approximately one-fifth of cellulase and xylanase activity. Particle-associated enzymes, potentially of bacterial origin, dominate hindgut digestion, akin to symbiotic strategies observed in select termites and passalid beetles. Our study sheds new light on the digestive prowess of panesthiine cockroaches, providing invaluable insights into the evolution of wood-feeding insects and their remarkable adaptability to challenging, nutrient-poor substrates. Full article

Adult cicadas pierce woody stems with their mouthparts to feed on xylem, suggesting the presence of cuticular adaptations that could increase hardness and elastic modulus. We tested the following hypotheses: (a) the mouthpart cuticle includes inorganic elements, which augment the mechanical properties; (b) these elements are abundant in specific mouthpart structures and regions responsible for piercing wood; (c) there are correlations among elements, which could provide insights into patterns of element colocalization. We used scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to investigate mouthpart morphology and quantify the elemental composition of the cuticle among four cicada species, including periodical cicadas (Magicicada sp.). Nanoindentation was used to quantify hardness and elastic modulus of the mandibles. We found 12 inorganic elements, including colocalized manganese and zinc in the distal regions of the mandible, the structure most responsible for piercing through wood; nanoindentation determined that these regions were also significantly harder and had higher elastic modulus than other regions. Manganese and zinc abundance relates to increased hardness and stiffness as in the cuticle of other invertebrates; however, this is one of the first reports of cuticular metals among insects with piercing-sucking mouthparts (>100,000 described species). The present investigation provides insight into the feeding mechanism of cicadas, an important but understudied component of their life traits. Full article

Xylotrechus chinensis (Chevrolat) (Coleoptera: Cerambycidae) is a serious wood-boring insect of mulberry trees (Morus spp.). Larvae of this species enter the trunk of the tree and feed on woody tissues. Xylotrechus chinensis is endemic in several Asian countries, while, in the last decade, it invaded Europe. In the present work, we evaluated trunk injection against this pest. The systemic insecticides fipronil, imidacloprid, and spirotetramat were used in the trials. Abamectin was used as a positive control since it has been found to be effective for the management of X. chinensis. Imidacloprid and fipronil proved to be highly effective against this species in both years (9.5 and 12.1 exit holes/tree in 2021, 5.0 and 8.8 exit holes/tree in 2022, respectively), while spirotetramat was the least effective. The lowest mean number of exit holes was recorded when abamectin was applied in both years (4.7 exit holes/tree in 2021 and 3.3 exit holes/tree in 2022). The percentage of exit holes was reduced by 76.1, 71.8, and 85.6% in trees treated with imidacloprid, fipronil, and abamectin, respectively, after two years of application, while spirotetramat caused a 37.4% reduction. Trunk injection with imidacloprid, fipronil, and abamectin could be used against X. chinensis for long-term control of mulberry trees. Full article

Black soldier fly larvae have gained popularity as an organic waste bio-conversional tool and fodder protein replacement in recent decades. It can consume all kinds of animal feces, kitchen waste and agricultural waste with great efficiency and transform them into high-value insect protein, fatty acids, and amino acids, which makes the larva a good substitute for costly fish meal and bean pulp in animal diets. However, excess chitin in the larva skin limits its application as an animal feed additive, consequently, employing fermentation with zymocytes to remove the chitin is necessary. In this study, we raised black soldier fly larvae (BSFL) with different carbon sources, such as chicken feces, straws and glucose, and examined the growth condition; we applied Bacillus subtilis and Aspergillus niger to co-ferment BSFL paste to analyze its nutrition changes. Data revealed that among the four kinds of cultures, the body weight of the corn powder group increased most rapidly; the wood chip group was the most underweight; however, it increased faster than others before day 4, and contained the least fat. Label-free quantitative proteomic analysis revealed that the expression of multiple enzymes from B. subtilis and A. niger involved in polysaccharide hydrolysis, amino acid biosynthesis and fatty acid metabolism, such as peptidase of S8 family, maltogenic α-amylase, oligo-1,6-glucosidase and lysophospholipase like protein changed significantly compared to the control group. Production detection showed that free amino acids, acid-soluble proteins, and short-chain fatty acids increased after fermentation; 13 out of 17 amino acids were increased and total free amino acids were increased from 0.08 g/100 g to 0.3 g/100 g; organic acids increased by 4.81 to 17 fold through fermentation, respectively; the actual protein content declined from 3.03 g/100 g to 1.81 g/100 g, the peptide content increased from 1.3 g/100 g to 2.46 g/100 g, the chitin degradation rate was 40.3%, and fat decreased 30% (p < 0.05). These findings might provide important information for future applications of black soldier fly larvae in different carbon waste recycling measures and material for animal feed/organic fertilizer after fermentation. Full article

Aromia bungii (Coleoptera: Cerambycidae) is an economically important wood-boring insect pest of stone fruit trees, particularly Prunus persica, in China. It has entered Japan and several European countries as an invasive species in recent years. It is difficult to control because of the cryptic feeding behaviour of larvae beneath the bark. Identification of repellent constituents from non-host plants has potential for use in management strategies against this beetle. Mentha spicata is cultivated extensively in Hebei Province (China) as a medicinal plant. Firstly, antennal responses of female A. bungii to M. spicata volatiles were evaluated by coupled gas chromatography-electroantennograms (GC-EAD), and then the EAD-active components were tested in semi-field trials. The results showed that A. bungii females were significantly repelled by myrcene, (S)-(+)-carvone, (E)-β-caryophyllene, and borneol compared with the control. The presence of myrcene (100 µL; 90% purity), (S)-(+)-carvone (200 µL; 96% purity), (E)-β-caryophyllene (500 µL; 98.5% purity), and borneol (800 µL; 80% purity) significantly reduced the perching rates of A. bungii females on both peach logs and leaves. Considering cost and commercial availability, we suggest that myrcene, (S)-(+)-carvone, and (E)-β-caryophyllene could be promising repellents against A. bungii females in the field. Full article

The pine wood nematode (PWN) Bursaphelenchus xylophilus has caused disastrous losses of pine forests in many countries, and the success of PWN depends strongly on interactions with its insect vectors. Monochamus saltuarius is a newly recorded vector in Northeast China. Feeding (i.e., immature) and egg-laying (i.e., mature) Monochamus spp. target different host plants, and olfactory cues play important roles regarding host choice. Whether infestation with PWN affects olfactory mechanisms in M. saltuarius related to feeding and oviposition is of interest as this may affect the spread of nematodes to new healthy hosts. However, little is known about molecular mechanisms of the olfactory system of M. saltuarius. We identified chemosensory-related genes in adult M. saltuarius and examined the influence of B. xylophilus on the respective expression patterns. Fifty-three odorant-binding proteins (OBPs), 15 chemosensory proteins, 15 olfactory receptors (ORs), 10 gustatory receptors, 22 ionotropic receptors (IRs), and two sensory neuron membrane proteins were identified, and sex bias among non-infested beetles was mainly found with respect to expression of OBPs. Interestingly, OBPs and ORs were markedly down-regulated in male M. saltuarius infested with B. xylophilus, which may reduce olfactory sensitivity of male M. saltuarius and affect the spreading of B. xylophilus to new hosts. Our results will help understand the interactions between B. xylophilus and M. saltuarius, which may lead to the identification of new control targets in the olfactory system of M. saltuarius. Full article

Invasions of exotic forest insects and pathogens can devastate evolutionarily naïve habitats and could cause irreversible changes to urban and natural ecosystems. Given the ever-increasing volume of trade in wood and plant stock worldwide, establishment of non-native pests under climate change is one of the most important forest health concerns currently. The European spruce bark beetle, Ips typographus, is a damaging, phloem-feeding insect of Norway spruce, Picea abies, in Eurasia. Endoconidiophora polonica is the most virulent ophiostomatoid fungal associate of I. typographus. Spruce species native to North America are susceptible to this insect-pathogen complex. We studied the suitability of ‘current’ (1970–2000) and future climates (2021–2100) in Canada and the United States for these two species via ensemble species distribution models. We also determined overlapping regions favorable to both I. typographus and E. polonica. Our results indicate that, currently, climate is particularly suitable for I. typographus and E. polonica in western Canada and throughout the United States. Northward shifts in climatic suitability are projected to occur in Canada for both species under climate change. By the end of the 21st century, a coast-to-coast corridor of climatic suitability for I. typographus and E. polonica will occur in Canada under high-temperature regimes. Full article

Symbiosis between insects and fungi arose multiple times during the evolution of both groups, and some of the most biologically diverse and economically important are mutualisms in which the insects cultivate and feed on fungi. Among these are bark beetles, whose ascomycetous cultivars are better known and studied than their frequently-overlooked and poorly understood basidiomycetous partners. In this study, we propose five new species of Entomocorticium, fungal mutualists in the Russulales (Basidiomycota) that are mutualistic symbionts of scolytine beetles. We have isolated these fungi from the beetle mycangia, which are structures adapted for the selective storage and transportation of fungal mutualists. Herein, we present the most complete phylogeny of the closely related genera Entomocorticium and Peniophora and provide insights into how an insect-associated taxon (Entomocorticium) evolved from within a wood-decaying, wind-dispersed lineage (Peniophora). Our results indicate that following a transition from angiosperms to gymnosperms, fungal domestication by beetles facilitated the evolution and diversification of Entomocorticium. We additionally propose four new species: Entomocorticium fibulatum Araújo, Li & Hulcr, sp. nov.; E. belizense Araújo, Li & Hulcr, sp. nov.; E. perryae Araújo, Li & Hulcr, sp. nov.; and E. macrovesiculatum Araújo, Li, Six & Hulcr, sp. nov. Our findings highlight the fact that insect-fungi associations remain an understudied field and that these associations harbor a large reservoir of novel fungal species. Full article