Search Results (10)

The potent and selective ‘genetic zipper’ method for insect pest control consists of three essential components: an antisense DNA (the finder), its complementary mature rRNA or pre-rRNA of the pest (the target), and the host’s endogenous DNA-guided rRNase (the degrader). Although this approach has been validated, the spectrum of effective rRNA targets remains insufficiently explored. In this study, we report for the first time the insecticidal efficacy of a novel oligonucleotide insecticide, Eriola-11, which targets the mitochondrial 16S rRNA of the woolly apple aphid Eriosoma lanigerum Hausmann. We hypothesized that the antisense-mediated silencing of mitochondrial rRNA would impair aphid viability and lead to physiological disruptions associated with mitochondrial energy metabolism. Eriola-11 was applied either once or twice (with a 24 h interval) to aphid-infested plants, and aphid mortality was recorded over 14 days. Mitochondrial 16S rRNA expression levels were quantified using molecular assays, and the degradation kinetics of Eriola-11 were assessed in aphid tissue homogenates. Results showed significant insecticidal activity, with 67.55% mortality after a single treatment and 83.35% after two treatments. Treated aphids exhibited the loss of their characteristic white woolly wax covering, and mitochondrial 16S rRNA expression was reduced 0.66-fold relative to the control. Additionally, Eriola-11 was fully degraded by aphid DNases from tissue homogenates within 3 h, highlighting its rapid biodegradability. These findings establish mitochondrial 16S rRNA as a viable target for antisense insecticides and expand the catalogue of potential rRNA-based targets, offering a promising avenue for environmentally sustainable pest control strategies. Full article

Evaluating cultivar susceptibility to biotic stressors in apple orchards is essential for selecting genotypes adapted to local conditions and for designing effective plant protection strategies. This study conducted a comparative assessment of five apple cultivars (‘Florina’, ‘Jonathan’, ‘Golden Delicious’, ‘Pinova’, and ‘Idared’) in response to major fungal diseases (Venturia inaequalis, Podosphaera leucotricha, and Monilinia spp.) and insect pests (Eriosoma lanigerum, Quadraspidiotus perniciosus, Anthonomus pomorum, Aphis spp., and Cydia pomonella). The cultivars were monitored over a five-year period in six orchards located in Central Transylvania, Romania. Significant differences in phytosanitary behavior were recorded among cultivars and locations. ‘Florina’ consistently showed the highest tolerance to pathogens and pests across all sites and years, while ‘Jonathan’ and ‘Golden Delicious’ proved highly susceptible, particularly to apple scab, powdery mildew, aphids, and codling moth. Pest incidence was strongly influenced by temperature, while disease occurrence was more closely linked to precipitation patterns. Heritability analysis indicated that genetic factors played a substantial role in shaping cultivar responses to most biotic stressors. The integrated approach to cultivar–location–pathogen and pest interactions offers practical insights for optimizing orchard protection strategies under variable ecological conditions. Full article

The woolly apple aphid—WAA (Eriosoma lanigerum Hausmann, 1802) poses a significant threat to intensive apple production. Given the limitations of conventional synthetic pesticides, there is an urgent need for effective and sustainable pest management strategies. Botanical extracts derived from plants with insecticidal properties mitigating aphid populations without adverse environmental impacts are scarce where WAA is concerned. Thus, the pertinent study aimed to investigate the aphicidal potential of Koelreuteria paniculata seed ethanolic extract (derived from the seed coat) and mechanically extracted oil (derived from the seed itself). At concentrations of 2.5% and 5%, both solutions expressed undeniable insecticidal potential, providing absolute (100%; oil) or significant (86–100%; ethanolic extract) mortality rates both in vivo and in vitro. Predominant phenolic compounds determined in the ethanolic extract were gallic and protocatechuic acids and three derivates—p-coumaric, quercetin, and luteolin acid derivates—contributing to more than 90% of the total phenolic content, while phenolic compounds were not detected in the oil, indicating activity of different active compounds. Although deriving from different seed parts and distinct extraction methods, both ethanolic extract and oil exhibited significant aphicidal effects against WAA. The integration of botanical extracts from invasive species into pest management practices supports ecological balance and sustainable agricultural productivity, fostering a healthier environment and more resilient agricultural systems. Full article

Nature-based solutions, such as biological control, can strongly contribute to reducing the use of plant protection products. In our study, we assessed the effect of augmentative releases of the European earwig (Forficula auricularia) to control the woolly apple aphid (Eriosoma lanigerum), a worldwide pest that causes serious damage to apple trees. The trials were carried out in two organic apple orchards located in Catalonia (NE Spain) from 2017 to 2020. Two treatments were compared: with vs. without earwig release. For the treatment, 30 earwigs per tree were released by means of a corrugated cardboard shelter. These releases were performed once per season and were repeated every year. We periodically assessed the length of the woolly apple aphid colonies, the number of colonies per tree, the percentage of aphids parasitized by Aphelinus mali, and the number of earwigs per shelter. Our results showed that earwig releases reduced the length of the colonies, but this effect was noticeable only for the second year onwards. Moreover, we found that those releases were compatible with A. mali. Overall, we demonstrated the positive impact of earwig releases on the woolly apple aphid control and the importance of considering time on augmentative biological control strategies. Full article

Many parasitoids need to feed on sugar sources at the adult stage. Although nectar has been proven to be a source of higher nutritional quality compared to honeydew excreted by phloem feeders, the latter can provide the necessary carbohydrates for parasitoids and increase their longevity, fecundity and host searching time. Honeydew is not only a trophic resource for parasitoids, but it can also constitute an olfactory stimulus involved in host searching. In this study, we combined longevity measurements in the laboratory, olfactometry and feeding history inference of individuals caught in the field to test the hypothesis that honeydew excreted by the aphid Eriosoma lanigerum could serve as a trophic resource for its parasitoid Aphelinus mali as well as a kairomone used by the parasitoid to discover its hosts. Results indicate that honeydew increased longevity of A. mali females if water was provided. Water could be necessary to feed on this food source because of its viscosity and its coating by wax. The presence of honeydew allowed longer stinging events by A. mali on E. lanigerum. However, no preference towards honeydew was observed, when given the choice. The role of honeydew excreted by E. lanigerum on A. mali feeding and searching behavior to increase its efficiency as a biological control agent is discussed. Full article

Exploration of plant secondary metabolites or by using them as leads for development of new pesticides has become one of the focal research topics nowadays. Herein, a series of new ester derivatives of piperine were prepared via the Vilsmeier–Haack–Arnold (VHA) reaction, and their structures were characterized by infrared spectroscopy (IR), melting point (mp), proton nuclear magnetic resonance spectroscopy (¹H NMR), and carbon nuclear magnetic resonance spectroscopy (¹³C NMR). Notably, the steric configurations of compounds 6 and 7 were confirmed by single-crystal analysis. Against T. cinnabarinus, compounds 9 and 11 exhibited 47.6- and 45.4-fold more pronounced acaricidal activity than piperine. In particular, compounds 9 and 11 also showed 2.6-fold control efficiency on the fifth day of piperine. In addition, compound 6 (>10–fold higher than piperine) displayed the most potent aphicidal activity against A. citricola. Furthermore, some derivatives showed good aphicidal activities against E. lanigerum. Moreover, the effects of compounds on the cuticles of T. cinnabarinus were investigated by the scanning electron microscope (SEM) imaging method. This study will pave the way for future high value added application of piperine and its derivatives as botanical pesticides. Full article

Diversifying agroecosystems through habitat management inside or outside production fields can provide alternative hosts and/or prey for natural enemies. In semi-natural habitats, parasitoids may find alternative host-plant complexes (HPC) that could allow their development when pest hosts are scarce in the field. However, morphological and physiological differences between alternative and targeted HPCs could affect the preference and fitness of the parasitoids, possibly altering their efficacy in regulating pests. In the present study, we examined two Aphelinus mali parasitoid populations developing on Eriosoma lanigerum from two host plants (Malus domestica-apple trees and Pyracantha coccinea). We hypothesized that A. mali from both HPCs will show different life history traits and behaviors because primary and alternative host-plants are known to induce variations in parasitoid biological performance. Our findings indicate that A. mali originating from E. lanigerum on P. coccinea parasitized more aphids and are smaller than those originating from E. lanigerum on apple. Furthermore, these parasitoids did not significantly vary their ability to attack and oviposit apple E. lanigerum, suggesting that P. coccinea could function as a suitable banker plant for A. mali. We discuss the potential use of P. coccinea in conservation biological control of E. lanigerum in apple orchards. Full article

The woolly apple aphid Eriosoma lanigerum (Homoptera: Aphidiae) is an important pest in apple orchards worldwide. Since the withdrawal or restricted use of certain broad-spectrum insecticides, E. lanigerum has become one of the most severe pests in apple growing areas across Western Europe. At present, effective limitation of woolly aphid populations relies on a good synergy between chemical control treatments and biological suppression by beneficial arthropods, especially by its main specific natural enemy, the parasitoid Aphelinus mali (Hymenoptera: Aphelinidae). To develop a knowledge-based decision support system, detailed monitoring data of both species were collected in the field (region of Sint-Truiden, Belgium) for a period of ten years (2010–2020). Aphelinus mali flights were monitored in the field, starting before flowering until the end of the second-generation flight at minimum. The seasonal occurrence of the most important management stages of E. lanigerum, e.g., start of wool production or activity on aerial parts in spring and migration of crawlers from colonies towards flower clusters or shoots, were thoroughly monitored. All obtained data were compared with historical and literature data and analysed in a population dynamics phenological model. Our outcomes showed that the emergence of first-generation A. mali adults (critical for the first parasitation activity and the basis for following A. mali generations in the continuation of the season) can be accurately predicted by the developed model. Hence, this information can be utilized to avoid insecticide sprayings with detrimental side effects at this particular moment as demonstrated by the outcomes of a field trial. In addition, the start of migration of E. lanigerum crawlers towards flower clusters or shoots is accurately predicted by the model. In conclusion, our results demonstrate that the model can be used as decision support system for the optimal timing of control treatments in order to achieve effective control of E. lanigerum with maximal biological suppression by its main natural enemy. Full article

(1) Habitat management can enhance beneficial arthropod populations and provide ecosystem services such as biological control. However, the implementation of ecological infrastructures inside orchards has a number of practical limitations. Therefore, planting/growing insectary plants in the margins of orchards should be considered as an alternative approach. (2) Here, we assessed the efficacy of a flower margin composed by four insectary plant species (Achillea millefolium, Lobularia maritima, Moricandia arvensis and Sinapis alba), which was placed on an edge of four Mediterranean apple orchards to attract natural enemies of two apple tree aphids (Dysaphis plantaginea and Eriosoma lanigerum). We also characterized the natural enemies present in the aphid colonies. (3) Our results show that the implementation of a flower margin at the edge of apple orchards attracts predators (Syrphidae, Thysanoptera, Araneae, Heteroptera, Coleoptera) and parasitoids. Parasitoids are the main natural enemies present in aphid colonies in our area. (4) The implementation of the flower margins successfully recruited natural enemy populations, and the presence of parasitoids in the surroundings of the orchards increased the parasitism of D. plantaginea colonies. Full article

The mitogenome of Mindarus keteleerifoliae Zhang (Hemiptera: Aphididae) is a 15,199 bp circular molecule. The gene order and orientation of M. keteleerifoliae is similarly arranged to that of the ancestral insect of other aphid mitogenomes, and, a tRNA isomerism event maybe identified in the mitogenome of M. keteleerifoliae. The tRNA-Trp gene is coded in the J-strand and the same sequence in the N-strand codes for the tRNA-Ser gene. A similar phenomenon was also found in the mitogenome of Eriosoma lanigerum. However, whether tRNA isomers in aphids exist requires further study. Phylogenetic analyses, using all available protein-coding genes, support Mindarinae as the basal position of Aphididae. Two tribes of Aphidinae were recovered with high statistical significance. Characteristics of the M. keteleerifoliae mitogenome revealed distinct mitogenome structures and provided abundant phylogenetic signals, thus advancing our understanding of insect mitogenomic architecture and evolution. But, because only eight complete aphid mitogenomes, including M. keteleerifoliae, were published, future studies with larger taxon sampling sizes are necessary. Full article