Journal of Plant Protection Research

The box tree moth, Cydalima perspectalis (Lepidoptera: Crambidae), is a significant invasive pest threatening boxwood (Buxus spp.) in Europe, North America, and parts of Asia. Since its initial detection in Europe in 2006, C. perspectalis has spread rapidly, causing widespread damage to both ornamental and wild boxwood populations. Although extensive investigations have been conducted on its biology, reproduction, ecology, and phenology, achieving fully sustainable control strategies in Europe remains challenging, even with numerous studies and pest management efforts documented in the literature. It is a highly polivoltine species, with larvae that aggressively consume boxwood foliage leading to defoliation and plant death. The economic impact in Europe has been particularly severe in natural landscapes, especially in historical gardens. C. perspectalis is highly adapted to feeding on boxwood. It is plausible that the microbiome of larvae might detoxify phytocompounds and modify plant defense thus facilitating their survival and proliferation. This review consolidates the current knowledge on C. perspectalis, including its biology, origin, and distribution. Based on currently available literature, effective management strategies, which primarily rely on monitoring and early detection, are discussed. Due to the challenges in controlling this pest and the lack of effective natural enemies an integrated pest management (IPM) approach is recommended. This strategy combines biological, chemical, and mechanical methods to reduce populations and limit their destructive impact. Furthermore, the pest’s ability to neutralize the natural toxins in boxwood leaves increases the risk of insecticide resistance development. Consequently, understanding the microbial interactions between C. perspectalis and its host plant could offer further pest control strategies by targeting the microbiome to disrupt the detoxification process, making the insect more susceptible to boxwood defenses.

Plant defensins have attracted much attention in the development of new antimicrobials. Yet the elucidation of their modes of action against bacterial pathogens is still incipient. The available recombinant systems to obtain plant defensin mutants with enhanced or optimized antibacterial activity may help to accelerate the knowledge of their action mechanisms and their applications against pathogens. In this work, the point mutant defensin K45E (J1-1_K45E) was obtained by the same recombinant system as J1-1 defensin. The characterized peptide conserved antibacterial activity against the gram-negative Pseudomonas aeruginosa and showed a dose improvement relative to J1-1. Furthermore, the mutant J1-1_K45E exhibited a gain in function against the gram-positive Staphylococcus aureus. Finally, to correlate structural changes and antibacterial activity, two properties involved in defensins’ modes of action were measured. First, the mutant J1-1_K45E which oligomerizes in a distinct pattern was compared with J1-1 and secondly, J1-1_K45E shows a distinct lipid binding profile because it binds preferentially to phosphatidylserine. Together, our findings support the idea that amino acid sequence variability in plant defensins superfamily can generate major functional changes, and highlight the relevant role of charged residues, beyond the g-core loop, in the improvement of J1-1 antibacterial activity.

Mealybug is a renowned pest known to attack agricultural products from the field to the post-harvest process, such as on the seed rhizomes of Curcuma aeruginosa. Therefore, this study aimed to examine and identify the species of mealybug on the seed rhizomes of C. aeruginosa based on morphological and molecular characteristics. Fifty mealybugs were collected from the seed rhizomes of C. aeruginosa in the storage room in Bogor (Indonesia) using a soft brush. They were transferred to new C. aeruginosa rhizomes without any other insects present. Morphological identification based on observation of mounted specimens of 10 female adults and six for molecular identification. The primer pair that amplified the mitochondrial cytochrome oxidase I (COI) gene was used to study the molecular characteristics and was continued with direct sequencing and sequence analysis. The results showed that the morphological characteristics of the mounted specimen were close to those of Pseudococcus jackbeardsleyi. Amplification of the COI gene yielded DNA bands measuring 490 base pairs (bp), while homology and phylogeny analysis confirmed the morphological identification. Based on BLAST analysis, the similarity of COI genes of mealybugs in this study was above 99% with other P. jackbeardsleyi. The study specimen was identified as P. jackbeardsleyi on the seed rhizomes of C. aeruginosa by comparing the morphological features of insect specimens and results of the species available in GeneBank. This result represented the first documented report about the presence of the species in storage.

Sweet alyssum (Lobularia maritima L.) is known as an insectary plant with great potential in enhancing the occurrence and diversity of beneficial insects in different crops. However, agronomic aspects of the introduction of this plant are still not fully recognized. Field studies aimed at assessing entomological relationships in the quasi-coordinate system focused on evaluating the impact of sweet alyssum as a companion plant in broad bean (Vicia faba L.) cultivation on the prevalence of the black bean aphid (Aphis fabae Scop.) and its natural enemies. It was also sought to determine the optimal row spacing for broad beans when introducing an additional plant between the rows. A 3-year field experiment involved various row spacings for broad beans: 50 cm, 65 cm, and 80 cm, with a control group at a 50 cm row spacing representing conventional cultivation, and another group with standard chemical pest protection as a reference. The results indicated that using sweet alyssum as a companion plant significantly reduced the black bean aphid population. It was comparable to the effect of chemical pest control. This companion planting also considerably increased the population of natural enemies of the black bean aphid, including hoverfly eggs and larvae, as well as various stages of ladybirds, particularly the adult stage. Sweet alyssum contributed to a reduced aphid-to-predator ratio, leading to a significant decrease in black bean aphid numbers and an earlier colonization of aphids by hoverflies and ladybirds on broad bean plants. In summary, sweet alyssum has the potential to effectively decrease black bean aphid occurrences, particularly on ecological farms. Notably, sweet alyssum’s competitiveness with broad beans and the different row spacing had minimal impact on predator occurrence, eliminating the need to increase standard row spacing for this plant.