Search Results (114)

Mountains are global biodiversity hotspots but face the danger of habitat loss, especially at lower elevations due to climate-warming-induced forest dieback. In the Gongga Mountains (SW China), Abies fabri trees at 2800 m show increased mortality, yet the causes remain unclear. We assessed climatic influences and bark beetle infestations on tree vigor and radial growth, comparing healthy and declining trees at 2800, 3000, and 3600 m elevations. Leaf nitrogen and phosphorus concentrations were measured to evaluate nutrient status. From 1950 to 2019, mean annual temperatures rose at all elevations, while precipitation decreased at low elevations, negatively correlating with temperature. Such warmer, drier conditions impaired low-elevation trees. The decline in A. fabri growth began in the late 1990s to early 2000s, with an earlier and more pronounced onset at lower elevations. A clear lag is evident, as trees at 3000 m and 3600 m showed either delayed or minimal decline during the same period. High-elevation trees experienced more stable climate and better nutrient availability, supporting greater growth and leaf nitrogen in healthy trees. Bark beetle infestations were worst in declining trees at the highest elevation. Our results reveal that A. fabri vigor shifts along elevation gradients reflect interactions between abiotic and biotic stressors, especially aridification. Full article

Common ragweed (Ambrosia artemisiifolia L.) has been identified as one of the most harmful invasive weed species in Europe due to its allergenic pollen and competitive growth in diverse habitats. In the first part of this review [Common Ragweed—Ambrosia artemisiifolia L.: A Review with Special Regards to the Latest Results in Biology and Ecology], its biological characteristics and ecological behavior were described in detail. In the current paper, control strategies are summarized, focusing on integrated weed management adapted to the specific habitat where the species causes damage—arable land, semi-natural vegetation, urban areas, or along linear infrastructures. A range of management methods is reviewed, including agrotechnical, mechanical, physical, thermal, biological, and chemical approaches. Particular attention is given to the spread of herbicide resistance and the need for diversified, habitat-specific interventions. Among biological control options, the potential of Ophraella communa LeSage, a leaf beetle native to North America, is highlighted. Furthermore, innovative technologies such as UAV-assisted weed mapping, site-specific herbicide application, and autonomous weeding robots are discussed as environmentally sustainable tools. The role of legal regulations and pollen monitoring networks—particularly those implemented in Hungary—is also emphasized. By combining traditional and advanced methods within a coordinated framework, effective and ecologically sound ragweed control can be achieved. Full article

Araucaria araucana is one of the longest-living Chilean trees. Recently, Araucaria Leaf Damage disease, which causes damage to branches and crowns, was detected. Sinophloeus porteri, a bark beetle affecting A. araucana, could be associated with foliar damage. However, little is known about their ecological and chemical interactions. This study examined the olfactory response of S. porteri to volatiles emitted from A. araucana. Branches and weevils were collected from a national park, and volatiles were trapped from both healthy and unhealthy branches. Thirty terpenes were identified, some of which were reported for the first time in A. araucana. Healthy branches emitted large amounts of myrcene (>360 ng g⁻¹ day⁻¹), and unhealthy branches showed high hibaene emanations (>140 ng g⁻¹ day⁻¹). Olfactory assays verified that S. porteri was attracted to the volatile blends of branches, regardless of the health condition of the branches, but preferred the blend of unhealthy branches. Moreover, myrcene was repellent to these weevils, and hibaene acted as an attractant, suggesting that A. araucana might use myrcene for defense against S. porteri, and hibaene could stimulate host selection by beetles. Full article

This study presents a taxonomic revision of the genus Macrima Baly, 1878 to advance the understanding of suprageneric, non-monophyletic “Monoleptites”. Through comprehensive morphological examinations of all type specimens, including detailed analyses of male and female genitalia and the structure of the cavitous anterior part of the head, we propose M. roseofulva Medvedev, 2011 and M. ferrugina Jiang, 1990 as new synonyms of M. aurantiaca (Laboissière, 1936), M. bifida Yang, 1992 a new synonym of M. cornuta (Laboissière, 1936), and M. yunnanensis (Laboissière, 1936) as a new synonym of M. pallida (Laboissière, 1936). In addition, M. costatipennis Jacoby, 1896 is transferred to Hoplosaenidea Laboissière, 1933 (comb. nov.). Color photos of habitus, body details, and genitalia are presented for all species. Full article

The northeast region of China plays a crucial role in crop production. The leaf beetle Monolepta hieroglyphica (Motschulsky, 1858) (Coleoptera: Chrysomelidae) has emerged as a potential threat to food security in the region. With a wide distribution spanning Asia and Russia, this beetle affects various crops. However, limited information is available regarding its occurrence patterns and genetic diversity among major crops in the region. Based on systematic observations across various hosts, coupled with genetic variation analysis using mitochondrial DNA markers, the main results were as follows. Leaf beetle occurrence varied among hosts, peaking from late July to mid-August, with maize and soybean fields exhibiting higher infestation rates compared with other crops. Notably, late-cultivated maize fields harbored the highest beetle numbers due to the species’ preference for young leaves. The host transfer trajectory may have originated in soybean and weeds, with subsequent alternation between host plants and other crops, before the final migration to cabbage and late-cultivated maize fields. Genetic analysis revealed nine COI haplotypes, four COII haplotypes, eleven Cytb haplotypes, and twenty-one combined haplotypes. No clear relationship existed between genetic diversity and occurrence, and no distinct host-based genetic patterns emerged from neighbor-joining tree and haplotype network analyses. High gene flow rates were observed, likely contributing to decreased genetic variation. An analysis of molecular variance results indicated major genetic variation within populations, although genetic distance and haplotype distribution indicated divergence among host populations. These results provide foundational data for developing effective M. hieroglyphica pest management strategies. Full article

Adhesion behavior between wet rice leaves and metal surfaces exacerbates the difficulty in separating and removing grains in the cleaning device. Reducing the adhesion between the wet rice leaves and the cleaning device is an important factor in improving the harvesting performance of rice combine harvesters. This paper investigates the possibility of reducing the adhesion between them. By studying the liquid shape characteristics between the removed grains and the surface, it was found that the adhesion force between the leaf and the surface is greatest when additional pressure is present. Based on biomimetic principles and the convex hull structure of a dung beetle’s head, a convex hull structure for the metal surface was designed to balance the atmospheric pressure on both sides of the leaf in order to eliminate additional pressure. Using the liquid bridge model between a spherical and a flat surface, a liquid bridge model for the leaf and convex hull surface was established. By optimizing the minimum liquid bridge force, the convex hull radius and distance were determined to be 2.47 mm and 1.38 mm, respectively. Contact and collision experiments verified that the convex hull surface is more effective in reducing the adhesion of moist leaves, providing a reference for future research on the cleaning methods of moist rice grains. Full article

The aquatic vegetable Brasenia schreberi Gmel. (Nymphaeales: Cabombaceae), widely cultivated in China, faces severe challenges from pest disturbances. With a field investigation, G. birmanica occurred for several generations in the Brasenia mono-cultivation system. The first visual peak on leaf surfaces appeared in July, with eggs, larvae, pupae and adults all being recorded. The highest number of flying adults were trapped in August in reverse to the absence of beetles on leaves, followed by an extraordinary high number of eggs in September. G. birmanica exhibited a conspicuous aggregation in distribution, with severely chewed areas having a G. birmanica abundance 21.6 times that of the non-chewed areas. Laboratory studies with GC–MS and two-choice tests revealed four volatiles significantly discrepant in contents released from chewed/intact leaves: cis-3-hexenyl acetate (917.33 ± 29.56 vs. 604.034 ± 23.24 ng, chewed vs. intact), 2-phenylethyl isothiocyanate (595.37 ± 28.42 vs. 356.00 ± 13.44 ng), undecane (771.44 ± 34.72 vs. 1003.28 ± 47.88 ng) and methyl salicylate (1079.84 ± 49.39 vs. 532.11 ± 18.23 ng); among them, 2-phenylethyl isothiocyanate could significantly attract G. birmanica adults. Our study suggests that G. birmanica can be a severe threat to mono-cultivated B. schreberi, whereas the damaged leaves may sacrifice themselves by attracting the beetles with an herbivore-induced volatile, thus protecting the whole plant population from pest disturbance. Full article

Monolepta hieroglyphica (Motschulsky) (Coleoptera: Chrysomelidae) is widely distributed in China and is polyphorous, being a major pest to cash crops, such as corn, cotton, and millet. Given the increasing severity of the greenhouse effect in recent years, we aimed to investigate the adaptability of M. hieroglyphica adults to varying temperatures. In this study, we assessed the survival, longevity, fecundity, feeding capacity, and antioxidant capacity of leaf beetle adults under laboratory conditions at 25–34 °C. Elevated temperatures (i.e., 31 and 34 °C) had (negative) impacts on M. hieroglyphica adults’ survival and reproduction. Similarly, the temperature negatively affected the feeding capacity of M. hieroglyphica adults, with the impact becoming more pronounced as the temperature increased. Under the same treatment time, the SOD and CAT activity levels increased with the increase in treatment temperature. The GST activity levels showed a decreasing trend. The POD activity showed a biphasic response to increasing temperatures, first decreasing and then increasing. The above indicates that different antioxidant enzymes of M. hieroglyphica adults have different levels of sensitivity to high temperatures. In the laboratory, our work analyzes the response of M. hieroglyphica adults to temperature from ecological and physiological research perspectives and provides strategies for strengthening its subsequent integrated pest management (IPM) under conditions of global warming or extreme weather events. Full article

Diapause, a survival strategy utilized by many insects under severe environmental conditions, can generate costs that potentially affect post-diapause development and reproduction. The willow leaf beetle, Plagiodera versicolora, overwinters as an adult. This study investigated the cold hardiness-hardiness and energy utilization of female P. versicolora, and their impact on post-diapause reproductive fitness. The supercooling point exhibited seasonal temperature variation, with the lowest points occurring in January and February, coinciding with the relatively lower ambient temperatures. Lipid content demonstrated a pronounced decline at the onset of diapause (from November to December) and stabilized from December to March. Glycogen content also showed a sharp decrease from November to January, subsequently stabilizing at relatively constant levels. In addition, trehalose content increased significantly when temperatures dropped (from November to January) and then decreased as temperatures rose (from January to March). There were no significant differences in the time from pairing to successful mating for post-diapause females compared with non-diapause females. However, mating duration and the pre-oviposition period for post-diapause individuals relative to non-diapause individuals increased, coupled with a reduction in the oviposition period, total number of eggs, number of egg clutches, and number of eggs per clutch; however, most importantly, there was no notable change in egg-hatching success. These results suggest that the cold-hardiness strategy of P. versicolora falls within the freeze-avoidance category, with energy usage predominantly reliant on lipids and carbohydrates during diapause initiation. Our findings also highlight that, although post-diapause females are capable of nutrient replenishment, the energetic demands of diapause result in considerable negative impacts on post-diapause female reproductive fitness. Full article

This study examined the impact of dung beetles on both sorghum growth and the physico-chemical properties of the soil over a two-month period. Four dung beetle species (Onthophagus vacca, Onthophagus marginalis subsp. andalusicus, Euonthophagus crocatus, and Gymnopleurus sturmi) were introduced into experimental setups, consisting of containers filled with sterilised clay-loam soil, with three treatment groups: [cow dung + beetles], [cow dung only], and a control group (no dung nor beetles), in order to evaluate their effects on various growth parameters, including the plant height, biomass, leaf area, and chlorophyll concentration. Additionally, changes in soil properties were assessed, focusing on the organic matter content, pH, conductivity, enzyme activities (e.g., urease, phosphatase), and microbial load. The results revealed significant increases in all the measured parameters across the treatments involving dung beetles, emphasising their role in enhancing soil fertility and plant productivity. The study also highlights the variation in effectiveness among the species, suggesting that beetle diversity plays a crucial role in nutrient cycling. Integrating dung beetles into sustainable farming practices could, therefore, serve as a key strategy to promote resilient agriculture. Full article

In Uganda, the common bean (Phaseolus vulgaris) is often infested by a complex of insect pests, but bean flies, aphids, bean leaf beetles, and flower thrips are the most important. Whereas yield losses due to these pests have been established, there is limited information on their population dynamics at different stages of crop growth and their effect on yield and yield components. In order to describe the population dynamics of selected common bean pests at various phases of bean crop growth, and their impact on yield and yield components, a study was carried out in Uganda during the 2016 second rains and the 2017 first rains in three agro-ecological zones. Bean flies, bean aphids, bean leaf beetles, whitefly, striped bean weevil, leafhoppers, and caterpillars were the main insects observed. Pesticide spray schedules were imposed to generate different populations of insect pests whose effects on yield and its components were determined. The findings indicate that spray regimes significantly influenced the abundance of bean flies and leafhoppers, but not the other insect pests. Additionally, except for caterpillars, insect pests were significantly influenced by crop growth stages, but only leafhoppers exhibited a significant negative relationship with grain yield. Furthermore, yield and yield components varied significantly between spray regimes, and there was a significant positive relationship between grain yield and yield components. Our study is important for informing growers on the stage of crop growth at which management tactics such as use of insecticides can be applied for different insect pests. Full article

Due to the significant threat to forest health posed by beetle infestations on pine trees, timely and accurate predictions are crucial for effective forest management. This study developed a pine tree stress probability prediction workflow based on monthly cloud-free Sentinel-2 composite images to address this challenge. First, representative pine tree stress samples were selected by combining long-term forest disturbance data using the Continuous Change Detection and Classification (CCDC) algorithm with high-resolution remote sensing imagery. Monthly cloud-free Sentinel-2 images were then composited using the Multifactor Weighting (MFW) method. Finally, a Random Forest (RF) algorithm was employed to build the pine tree stress probability model and analyze the importance of spectral, topographic, and meteorological features. The model achieved prediction precisions of 0.876, 0.900, and 0.883, and overall accuracies of 89.5%, 91.6%, and 90.2% for January, February, and March 2023, respectively. The results indicate that spectral features, such as band reflectance and vegetation indices, ranked among the top five in importance (i.e., SWIR2, SWIR1, Red band, NDVI, and NBR). They more effectively reflected changes in canopy pigments and leaf moisture content under stress compared with topographic and meteorological features. Additionally, combining long-term stress disturbance data with high-resolution imagery to select training samples improved their spatial and temporal representativeness, enhancing the model’s predictive capability. This approach provides valuable insights for improving forest health monitoring and uncovers opportunities to predict future beetle outbreaks and take preventive measures. Full article

The poplar bark beetle Trypophloeus binodulus (Coleoptera: Scolytidae) is a key pest of poplar trees (Malpighiales: Salicaceae, genus Populus) across northern Spain. However, among the more than 200 poplar clones available on the market, the clone USA 184-411 has the highest susceptibility to T. binodulus attacks. We tested the hypothesis that compounds released by the most susceptible poplar clone chemically mediate Trypophloeus binodulus behavior. The leaf and bark volatile chemical profile composition of host poplar Populus nigra L. (Salicaceae) clones were analyzed and tested on adult T. binodulus by electroantennography (EAG) and by monitoring their populations in baited traps in northern Spain. The collection of volatiles released by the leaves and bark of both clones by SPME revealed the emission of 53 components from different chemical classes. Salicylaldehyde dominated these collections of leaf volatiles and was more abundant in aerations of the more susceptible poplar clone (USA 184-411). The EAG response of adult beetles to salicylaldehyde was higher than that of any other plant odorants. In field trials, traps baited with salicylaldehyde + ethanol significantly captured more adults than all other treatments, irrespective of other lure components. The present study could aid in developing semiochemical-based management tactics against this important pest. Full article

Oulema melanopus L., 1758 (Coleoptera: Chrysomelidae) is one of the significant pests affecting cereal crops in Europe. Its damage is evident in the destruction of leaves during the spring growing season, leading to substantial impacts on both the quantity and quality of the harvested yields. The study aimed to evaluate the extent of leaf surface damage, changes in chlorophyll content caused by this pest, and the subsequent effects on yield quality. To achieve this, two experimental parcels were established, each subjected to different pesticide treatments during the spring vegetation cycle, but notably, with the difference that one parcel did not receive insecticide applications. The phytosanitary status, yield quantity, and quality parameters of thes parcels were compared. Chlorophyll content in damaged and undamaged plants was monitored in vivo using SPAD measurements, while the extent of leaf surface damage was assessed through image analysis using GIMP software 2.10.32. Harvested grain underwent milling and baking analysis, with milling and baking-quality indicators measured using a NIR grain analyzer. The results revealed that omitting springtime insecticide treatments during the emergence of O. melanopus led to significant reductions in leaf area and yield quality. In untreated parcels, leaf decession followed linear progression, reaching 35–40% within 20 days. This damage correlated with the decline in SPAD index values, indicating a 40–50% reduction in chlorophyll content dependent photosynthetic activity. Consequently, there were substantial decreases in milling and baking qualities, including nearly 30% reductional protein-content indicators and 10% in the Hagberg falling number. In summary, our large-scale field experiments demonstrated that persistent O. melanopus damage in wheat fields significantly reduced both the quantity and quality of yields, particularly protein content. These facts underscore the economic importance of timely pest-control measures to mitigate damage and preserve crop value. Full article

Okra (Abelmoschus esculentus) is an important agricultural crop of the Malvaceae family, cultivated across tropical, subtropical, and warm temperate regions. However, okra production faces numerous challenges from diverse pest species, including insects, nematodes, arachnids, and mites, that significantly reduce its yield. Major economic pests include the cotton aphid, cotton spotted bollworm, Egyptian bollworm, cotton mealybug, whitefly, cotton leafhopper, cotton bollworm, two-spotted spider mite, root-knot nematode, reniform nematode, cotton leaf roller, and flea beetle. Additionally, less prevalent pests such as the blister beetle, okra stem fly, red cotton bug, cotton seed bug, cotton looper, onion thrips, green plant bug, and lesion nematode are also described. This review also addresses fungal and oomycete diseases that present high risks to okra production, including damping-off, powdery mildew, Cercospora leaf spot, gray mold, Alternaria leaf spot and pod rot, Phyllosticta leaf spot, Fusarium wilt, Verticillium wilt, collar rot, stem canker, anthracnose, and fruit rot. In addition to these fungal diseases, okra is also severely affected by several viral diseases, with the most important being okra yellow vein mosaic disease, okra enation leaf curl disease, and okra mosaic disease, which can cause significant yield losses. Moreover, okra may also suffer from bacterial diseases, with bacterial leaf spot and blight, caused primarily by Pseudomonas syringae, being the most significant. This manuscript synthesizes the current knowledge on these pests. It outlines various management techniques and strategies to expand the knowledge base of farmers and researchers, highlighting the key role of integrated pest management (IPM). Full article