Search Results (69)

Empoasca onukii severely damages tea plants as a major sap-sucking pest, leading to the increasing adoption of biopesticides as a sustainable alternative to chemical control. However, existing research has largely focused on the final lethal effects of these agents, while their short-term interference patterns on pest feeding behavior remain unclear. In this study, six biopesticides—azadirachtin, matrine, Beauveria bassiana, Metarhizium anisopliae CQMa421, Mamestra brassicae nucleopolyhedrovirus (MbNPV), and Bacillus thuringiensis (Bt)—were evaluated using the electrical penetration graph (EPG) technique to precisely analyze their interference on the short-term (6 h) feeding behavior of E. onukii, alongside field trials to validate control efficacy. EPG analysis revealed that different types of biopesticides significantly disrupted feeding in distinct ways. The two botanical pesticides and CQMa421 mainly prolonged the non-probing phase (waveform Np) and reduced active non-phloem feeding (C waveform) (p < 0.05); Bt and B. bassiana significantly extended the resting phase (waveform R) and decreased the frequency of passive phloem feeding (waveform E) (p < 0.05), whereas MbNPV exhibited a combined effect, simultaneously prolonging both Np and R waveforms while reducing waveform C (p < 0.05). Field trials showed that all tested treatments achieved complete control (100%) at 21 days post-application. Moreover, across a wide range of concentrations, they all demonstrated excellent and stable control performance. These findings provide diverse agent options for the green control of E. onukii in tea plantations and lay a foundation for constructing a green integrated pest management system centered on biological control for tea plant pests. Full article

Hemipteran plant sap feeders acquire food by inserting their piercing–sucking mouthparts into the apoplast (xylem sap feeders) or symplast (phloem sap feeders). When feeding, these insects seal their stylets inside the plant with a salivary sheath, minimising embolisms. The main impact of the insect on the host or food plant consists of sucking plant sap, transmitting phytopathogenic agents, or triggering galls as hypertrophic and/or hyperplastic neoformations. This paper proposes a rapid method for locating and counting the salivary sheaths of Philaenus spumarius (the Meadow Spittlebug), the primary Italian vector of Xylella fastidiosa, at the feeding point on its host or food plants. Hand-sliced stems of herbs hosting juveniles and olive twigs or leaves feeding the adult spittlebug, preserved while mounted in 75% ethanol (v/v), show the salivary sheaths. Alternative dyeing with acid fuchsin, chlorazol black, or phloroglucinol, and diaphanisation with Essig’s fluid alone or in combination with benzyl alcohol, may help with observations. The 75% EtOH solution provides a better compromise, yielding rapid evidence. The other methods offer similar outcomes but require more time and effort and expose the operator to harmful dyes. Assessing vectors’ access to plants may enable us to quantify the potential number of pathogen transmission events or to spot rejecting clones, thereby advancing the development of robust, effective control strategies that incorporate resistance. Full article

Urban green spaces host complex arthropod communities, in which natural insect antagonists play a key role in regulating pest populations. The jumping plant-louse Cacopsylla pulchella is a sap-sucking pest widespread across Europe that attacks Cercis siliquastrum L., which is commonly used as an ornamental tree. Heavy infestations may contribute to host tree decline and cause indirect damage in urban environments by reducing aesthetic value and by extensive deposition of honeydew secretions on surrounding surfaces. As with many phytophagous insects occurring in urban contexts, information on the natural enemies of this species remains limited, particularly in Italy, and requires further documentation. Here, we investigated the parasitoids associated with C. pulchella in central and southern Italy based on surveys conducted between 2022 and 2025. Specimens were obtained from infested plant material and identified using an integrative taxonomic approach combining detailed morphological examination with DNA barcoding. Prionomitus mitratus was confirmed as the primary parasitoid of C. pulchella, while two species, Pachyneuron muscarum and Pachyneuron aphidis, were identified as hyperparasitoids. In addition, a single specimen of Anastatus bifasciatus was also recorded emerging from the psyllid as a hyperparasitoid. Molecular analyses generated the first publicly available mitochondrial and nuclear sequences for P. mitratus. For Pachyneuron, molecular results showed variable correspondence with available reference sequences, reflecting the uneven representation of species-level data for Pteromalidae in public databases. By integrating morphological and molecular evidence, this study clarifies trophic relationships within the C. pulchella parasitoid complex. It provides vouchered molecular references to support future taxonomic and ecological research in urban ecosystems. Full article

The use of fungal entomopathogens, such as Metarhizium anisopliae, is a promising alternative for pest biocontrol but suffers the disadvantage of a relatively slower killing speed when compared with chemical pesticides. Nilaparvata lugens (brown planthopper, BPH) is a destructive sap-sucking pest that seriously threatens rice production worldwide. In the present study, we characterized a key immune-regulating protein, Spätzle (SPZ), encoding gene NlSPZ5 in BPH, and constructed a transgenic strain of M. anisopliae that expressed a specific dsRNA targeting the NlSPZ5 gene for enhancing the fungal virulence. Expression pattern analysis revealed that NlSPZ5 was expressed with the highest levels in the second-instar nymphs and hemolymph and could be largely activated by M. anisopliae infection. Microinjection of dsNlSPZ5 resulted in a markedly decreased survival rate and increased susceptibility to fungal infection in BPH. Notably, a transgenic strain of M. anisopliae expressing dsNlSPZ5 could effectively suppress the target gene expression and promote fungal proliferation in BPH upon fungal challenge. Compared to the wild-type strain, the transgenic fungal strain exhibited significantly enhanced insecticidal efficacy against BPH without compromising mycelial growth and sporulation. Our results demonstrate that fungal entomopathogens used as a delivery vector to express dsRNAs targeting insect immune defense-associated genes can effectively augment their virulence to the host insect, providing clues to develop novel pest management strategies through the combination of RNAi-based biotechnology and entomopathogen-based biocontrol. Full article

Aphids are sap-sucking pests that cause substantial damage to fruit and fibre crops through direct feeding and transmission of plant viruses. While chemical pesticides remain the primary method of control, their use raises concerns related to human health, environmental contamination, pesticide resistance, and impacts on beneficial insects. As a sustainable alternative, spray-on double-stranded RNA (dsRNA) technology offers a promising approach to induce RNA interference (RNAi) in target pests. For RNAi to be effective against sap-sucking insects like the green peach aphid (Myzus persicae), it is essential to identify genes whose silencing disrupts vital physiological functions. In this study, artificial diet (AD)-based feeding assays were used to evaluate dsRNAs targeting eight genes involved in neural function, osmoregulation, feeding behaviour, and nucleic acid/protein metabolism. dsRNAs were administered individually, in combinations, or as a multi-target stacked construct. After 98 h of feeding, aphid mortality ranged from 14 to 72% (individual targets), 78–85% (combinations), and 54% (stacked construct). Transcript knockdown varied from 6.3% to ~54%, though a consistent correlation with mortality was not always observed. The gene targets and combinatorial dsRNA strategies identified in this study provide a foundation for developing RNAi-based crop protection technologies against M. persicae infestation. Full article

The whitefly (Bemisia tabaci) (Hemiptera: Aleyrodidae) is a small phytophagous invertebrate of herbaceous plants, shrubs, trees, wild plants, and crops of economic importance. It generates substantial economic losses due to direct damage caused by sap sucking and virus transmission. This work presents referential images of the morphology of B. tabaci and one of its main biological controllers in southern South America, thus serving as a reference for other researchers. In addition, results are presented of studies carried out to evaluate the pathogenicity of two fungal isolates (previously selected in vitro against Sclerotinia sclerotiorum and Botrytis cinerea and plant growth promoters) identified as Metarhizium taii CEP-722 and Trichoderma afroharzianum CEP-754 in immature stages of B. tabaci in tomato plants (Solanum lycopersicum). The trials were conducted under controlled conditions in controlled chambers, ensuring optimal growth conditions for B. tabaci, after morphological prospection, collection, identification, and mass rearing of adults in entomological cages. The results indicate that M. taii CEP-722 caused approximately 30% mortality in the immature stages of B. tabaci, while T. afroharzianum CEP-754 did not increase mortality under the experimental conditions. This study provides new knowledge on the potential of M. taii as a biological control agent against B. tabaci, offering a promising alternative in integrated pest management strategies. The results with T. afroharzianum suggest that further methodologies or combinations should be explored to improve its efficacy. Full article

The invasive sap-feeding pest Toumeyella parvicornis (pine tortoise scale) is rapidly spreading across Europe, threatening pine ecosystems, particularly in forest–urban areas of Italy. In this scenario, early detection and monitoring strategies are critical to prevent new outbreaks and mitigate impacts in infested regions. Current surveillance is challenged by the lack of rapid, sensitive tools for indirect detection of this cryptic, canopy-dwelling pest, despite advancements in molecular diagnostics and environmental DNA (eDNA). Here, we established a highly specific qPCR assay using LNA probe chemistry for detecting T. parvicornis DNA from both adult insects and their excreted honeydew. DNA was successfully isolated/quantified from all tested matrices. We recorded average Cq values of 20.9 for insect specimens and 30.3 for collected honeydew samples. Targeting the COI barcoding region, the assay demonstrated excellent specificity in both in silico and in vitro tests, showing no cross-reactivity to other pine-associated taxa. The limit of detection for DNA isolated from insect was 64 fg/µL. This is the first diagnostic protocol to use honeydew as a matrix for indirect detection of T. parvicornis. Optimized for routine application by Plant Health Services, this eDNA-based tool offers a valuable approach for future monitoring of sap-sucking hemipterans in multiple environments. Full article

Orange spiny whitefly (Aleurocanthus spiniferus Quaintance) is a major pest with economic significance to tea plants, as both nymphs and adults suck plant sap and contribute to the development of tea sooty mold. The occurrence of this pest varies considerably among different tea cultivars, even within the same plantation. This study aims to characterize the bioactive constituents of tea volatiles mediating A. spiniferus host selection, and leverage these semiochemicals to develop effective field trapping systems. Through field investigations and Y-tube olfactometer tests, we identified two highly preferred tea cultivars (‘Huangjinya’ and ‘Fuding white tea’) and two cultivars (‘Baiye No. 1’ and ‘Longjing 43’) that were not preferred. Behavioral assays and gas chromatography-mass spectrometry (GC-MS) analysis revealed four attractive compounds [hexanol, (E)-2-hexenal, linalool, and (E,E)-α-farnesene] and two repellent compounds [nonanal and (Z)-3-hexenol] in the volatile emissions of the four cultivars. A hexane solution (10 µL) of nonanol, (Z)-3-hexenol, linalool, and (E,E)-α-farnesene at a concentration of 100 µg/µL was able to elicit an obvious electrophysiological (EAG) response. In field trials, the synergistic bait trap equipped with two types of attractants, 500 µL of hexane solution of the mixture of linalool and (E,E)-α-farnesene (3:1, v/v), and the mixture of linalool and (Z)-3-hexenol (3:1, v/v) at the concentration of 100 μg/μL, showed significantly higher attractant efficacy and selectivity. Overall, this study indicates that tea volatiles play a crucial role in the host selection of A. spiniferus, and the synthetic mixtures of tea volatiles have the potential to be developed as commercial plant-based attractants for adult A. spiniferus. This study contributes to the development of sustainable, environmentally friendly management strategies for a pest that is challenging to prevent and control. Full article

The cotton aphid, Aphis gossypii Glover, is among the most economically significant sap-sucking insect pests, inflicting substantial economic losses worldwide. Insecticides such as thiamethoxam, bifenthrin, and flonicamid are commonly used to manage this pest, despite the inherent risk of developing resistance. In this study, we investigated the evolution of insecticide resistance in A. gossypii after continuous selection with thiamethoxam, bifenthrin, and flonicamid over more than ten generations in a controlled laboratory environment. We assessed the fitness of resistant strains using an age-stage, two-sex life table approach, comparing them to a susceptible population. The results indicated that A. gossypii achieved resistance levels of 158.60-fold against thiamethoxam, 129.18-fold against bifenthrin, and 104.75-fold against flonicamid. Furthermore, life table analyses revealed that the developmental stages were significantly extended, while longevity decreased in all resistant strains compared to the susceptible population. Additionally, the net reproductive rate (R₀), fecundity, and reproductive days were notably reduced in the resistant cohorts when compared to the susceptible strain. Overall, these findings provide valuable insights into the laboratory-induced evolution of insecticide resistance and the associated fitness costs in A. gossypii when feeding on cotton plants. This information could be instrumental in formulating effective resistance management strategies to control this significant pest. Full article

The tea mosquito bug, Helopeltis theivora Waterhouse, (Hemiptera: Miridae) is a significant sap-sucking pest in tropical tea plantations that causes substantial losses in tea production on Hainan Island, China. The morphological and ultrastructural characteristics of H. theivora antennae have not been elucidated. Here, we used several microscopy techniques (SDM, SEM, and TEM) to investigate the morphology as well as the setae and sensilla on the antennae of nymphs and adults of H. theivora. SDM observations indicated that the antennae of H. theivora were filamentous in shape and included four segments: scape, pedicel, flagellum I, and flagellum II. The length of the antenna was approximately twice that of the body and the setae were enriched in flagellum II. The SEM results showed that there were a total of six types of sensilla on the antenna of H. theivora, including the sensilla chaetica (SCh), sensilla trichoidea (ST), sensilla basiconica (SB), sensilla coeloconica (SCo), sensilla mammilliformia (SM), and Böhm’s bristles (BB). In particular, there were three subtypes (I, II, and III) of different lengths in SCh and SB, and two subtypes of straight (I) and curved (II) sensilla in ST. The TEM results indicated that diverse internal structures were present in SCh, ST, SB, and SCo, suggesting different functions and different sensory mechanisms of these four main sensilla in the orientation behavior of H. theivora on tea plants. These findings provide a theoretical basis for further exploration of the olfactory orientation of H. theivora in tropical tea plantations and pave the way for the development of semiochemical-based control options in the future. Full article

During the flowering period of mango trees, pests often hide in the inflorescences to suck sap, affecting fruit formation. By accurately detecting the number and location of mango inflorescences in the early stages, it can help target-specific spraying equipment to perform precise pesticide application. This study focuses on mango panicles and addresses challenges such as high crop planting density, poor image quality, and complex backgrounds. A series of improvements were made to the YOLOv8 model to enhance performance for this type of detection task. Firstly, a mango panicle dataset was constructed by selecting, augmenting, and correcting samples based on actual agricultural conditions. Second, the backbone network of YOLOv8 was replaced with FasterNet. Although this led to a slight decrease in accuracy, it significantly improved inference speed and reduced model parameters, demonstrating that FasterNet effectively reduced computational complexity while optimizing accuracy. Further, the GAM (Global Attention Module) attention mechanism was introduced as an attention module in the backbone network to enhance feature extraction capabilities. Experimental results indicated that the addition of GAM improved the average precision by 2.2 percentage points, outperforming other attention mechanisms such as SE, CA, and CBAM. Finally, the model’s bounding box localization ability was enhanced by replacing the loss function with WIoU, which also accelerated model convergence and improved the mAP@.5 metric by 1.1 percentage points. Our approach demonstrates a discrepancy of less than 10% compared to manual counted results. Full article

Honey, a natural food with a rich history, is produced by honeybees and other species of bees from nectar, other plant fluids, and honeydew of sap-sucking insects. During foraging, these bees may be exposed to plant protection products (PPPs), metals, and metalloids, potentially leading to residues in honey and hive products that could have a negative impact on human safety. Recognizing the lack of an appropriate methodology for pesticide contamination of honey and other hive products, this research aims to support the need for studies on residues in pollen and bee products for human consumption to establish safe maximum residue levels (MRLs) for consumers. A UHPLC-MS/MS residues method and a modified QuEChERS extraction were applied to simultaneously determine 237 pesticide residues in honey and pollen. The study in North Sardinia analyzed honey and pollen samples from six areas for pesticide residues and verified 27 heavy metals and metalloid residues using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The data obtained showed residues at levels close to the LOQ of the method, cycloate in a few samples of pollen, and dichlorvos, zoxamide, cycloate, and chlorantraniliprole in honey samples. All samples showed the absence of heavy metal contamination. Overall, no risk to human health was identified. The results of this study confirm that honey and pollen may be a good bioindicator of environmental contamination of a wide area surrounding honeybee hives. Full article

Aphids are small, notorious insect pests that negatively impact plant health and agricultural productivity through direct damage, such as sap-sucking, and indirectly as vectors of plant viruses. Plants respond to aphid feeding with a variety of molecular mechanisms to mitigate damage. These responses are diverse and highly dynamic, functioning either independently or in combination. Understanding plant–aphid interactions is crucial for revealing the full range of plant defenses against aphids. When aphids infest, plants detect the damage via specific receptor proteins, initiating a signaling cascade that activates defense mechanisms. These defenses include a complex interaction of phytohormones that trigger defense pathways, secondary metabolites that deter aphid feeding and reproduction, lectins and protease inhibitors that disrupt aphid physiology, and elicitors that activate further defense responses. Meanwhile, aphids counteract plant defenses with salivary effectors and proteins that suppress plant defenses, aiding in their successful colonization. This review offers a detailed overview of the molecular mechanisms involved in plant–aphid interactions, emphasizing both established and emerging plant defense strategies. Its uniqueness lies in synthesizing the recent progress made in plant defense responses to aphids, along with aphids’ countermeasures to evade such defenses. By consolidating current knowledge, this review provides key insights for developing sustainable strategies to achieve crop protection and minimize dependence on chemical pesticides. Full article

Different herbivorous species that share a host plant may interact via competition or facilitation, depending on whether the interaction partners are hindered by or benefit from the interaction. Sap-sucking insects, such as aphids, can influence each other indirectly by altering the composition of the shared phloem sap. Aphid-induced changes in the plant may affect aphid performance and lead to a shift in the balance between different co-occurring aphid species. In this study, we compared the performance of the English grain aphid (Sitobion avenae) and the bird cherry-oat aphid (Rhopalosiphum padi) simultaneously infesting leaves or ears of wheat (Triticum aestivum) plants, which had been either previously infested by S. avenae or kept uninfested. Colonies of S. avenae were larger on ears than on leaves, while the opposite pattern was found for R. padi. Pre-infestation of ears, but not of leaves, by S. avenae led to a higher total aphid number and colony size of S. avenae at some time points. The balance between the two species was only slightly affected by previous infestation at some time points. The findings of this study contribute to the understanding of plant–aphid as well as aphid–aphid interactions in agricultural fields. Full article

Psyllids (Hemiptera: Psylloidea) are plant sap-sucking insects whose identification is often difficult for non-experts. Despite the rapid development of DNA barcoding techniques and their widespread use, only a limited number of sequences of psyllids are available in the public databases, and those that are available are often misidentified. Here, we provide 80 sequences of two mitochondrial genes, cytochrome c oxidase I (COI) and cytochrome b (Cytb), for 25 species of Aphalaridae, mainly from Bulgaria. The DNA barcodes for 15 of these species are published for the first time. In cases where standard primers failed to amplify the target gene fragment, we designed new primers that can be used in future studies. The distance-based thresholds for the analysed species were between 0.0015 and 0.3415 for COI and 0.0771 and 0.4721 for Cytb, indicating that the Cytb gene has a higher interspecific divergence, compared to COI, and therefore allows for more accurate species identification. The species delimitation based on DNA barcodes is largely consistent with the differences resulting from morphological and host plant data, demonstrating that the use of DNA barcodes is suitable for successful identification of most aphalarid species studied. The phylogenetic reconstruction based on maximum likelihood and Bayesian inference analyses, while showing similar results at high taxonomic levels to previously published phylogenies, provides additional information on the placement of aphalarids at the species level. The following five species represent new records for Bulgaria: Agonoscena targionii, Aphalara affinis, Colposcenia aliena, Co. bidentata, and Craspedolepta malachitica. Craspedolepta conspersa is reported for the first time from the Czech Republic, while Agonoscena cisti is reported for the first time from Albania. Full article