Explore the vast range of titles available.

The sweet potato (cotton) whitefly Bemisia tabaci is a major agricultural pest in various fields and vegetable crops worldwide. It causes extensive damage by direct feeding on plants, reducing quality, secreting honeydew and transmitting plant viruses. B. tabaci is known for its genetic diversity and considered a complex of biotypes or, as suggested, a complex of distinct cryptic species. Management of whiteflies relies mainly on the use of insecticides; however, its ability to develop resistance to major insecticide classes creates a serious challenge to farmers and pest control specialists. Among the cryptic species of B. tabaci , MED is considered more resistant than the MEAM1 to insecticides such as pyriproxyfen and neonicotinoids; however, in recent years there are other species of B. tabaci including MEAM1, Asia I and Asia II-1 that have developed high resistance to various groups of insecticides. Advanced methods based on molecular and gene sequence data obtained from resistant and susceptible field-collected B. tabaci populations resulted in a better understanding of resistance mechanisms in this pest. Several components of IPM-IRM (Integrated Pest Management-Insecticide Resistance Management) programs such as selective and biorational insecticides, insecticide rotation with different modes of action and nonchemical control methods are among the countermeasures of insecticide resistance management for this pest. In the current review, we concentrate on insecticide resistance and resistance management of B. tabaci, focusing on reports published mainly over the past 10 years.

The tomato borer Tuta absoluta is a major pest of tomato mainly controlled by chemical insecticides. However, development of resistance to specific chemical classes has made control of the pest extremely difficult. Emamectin benzoate belongs to the avermectin mode of action and to date, low or no resistance levels against this insecticide have been documented. Recently, reduced efficacy of emamectin benzoate was documented, in a field population from Crete (ninefold resistant ratio (RR)). Subsequent laboratory selections with emamectin benzoate for eight sequential generations resulted in an increase of the RR to 60-fold, the highest resistance level reported to the particular insecticide. Hereby, we are presenting the characterization of emamectin benzoate resistance in T. absoluta . Sequencing of the GluCl and GABA receptor (rdl) genes, the molecular targets of emamectin benzoate indicted absence of non-synonymous SNPs. The use of known enzyme inhibitors (PBO, DEF and DEM) revealed that P450s partially synergized emamectin benzoate resistance, suggesting potential implication of metabolic resistance. RNAseq approach was used to identify differentially expressed genes, from emamectin benzoate resistant and susceptible T. absoluta populations. Twelve libraries were sequenced using the Illumina platform, which generated 81 Gbp, thus substantially increasing the number of publicly available genomic resources for this species. The de novo transcriptome assembly consisted of 549,601 contigs, grouped in 233,453 unigenes. Differential expression analysis and qPCR validation revealed over-expression of one unigene similar to cytochrome P450 (Clan 4) potentially implicated in emamectin benzoate resistance, supporting further the involvement of P450s in the observed resistance phenotype.

The tomato borer Tuta absoluta (Lepidoptera: Gelechiidae) is an invasive pest of tomato crops that is rapidly expanding around the world. It is considered a devastating pest and its control heavily relies on application of insecticides. Diamides are a novel class of insecticides acting on insect ryanodine receptors and are highly effective against lepidopteran pests. To date, chlorantraniliprole and flubendiamide have been registered in the market and they have been extensively used to manage T. absoluta. In this study, a survey was conducted in Greece and Italy monitoring diamide resistance. The populations originating from Sicily (Italy) exhibited LC₅₀s that ranged between 47.6–435 for chlorantraniliprole and 993–1.376 for flubendiamide, while for Crete (Greece) LC₅₀s ranged between 0.14–2.45 for chlorantraniliprole and 1.7–8.4 for flubendiamide (LC₅₀s in mg L⁻¹). Comparing this result to the susceptible reference strain, high resistance levels for the Italian populations were detected, i.e., up to 2,414- and 1,742-fold for chlorantraniliprole and flubendiamide, respectively. Resistance ratios for Greek populations were found up to 14-fold for chlorantraniliprole and 11-fold for flubendiamide, suggesting that diamide resistance is low but increasing considering monitoring data over time. Hereby, we report for the first time, cases of resistance development to diamide insecticides in T. absoluta. These findings underline the importance of committing to the resistance management strategies for diamide insecticides.

Pesticides are widely used to protect agricultural products from pests and diseases. Although a strict regulatory framework exists in the EU, concerns about pesticide residues in food are retained among consumers. This study represents the first large sample (N = 1846) attempt to identify the main predictors influencing Greek consumers’ attitude concerning the benefits—risks ratio of pesticide use. After a principal components analysis and a bivariate logistic regression were performed, it was found that Greek consumers express high concerns from pesticide residues in food regarding their loved ones and their own health. At the same time, however, they recognize to a significant extent beneficial contributions of the use of pesticides to food security and the national economy, as well. Several significant predictors of consumer’s attitude towards benefit—risks perception of pesticide use was identified, concerning personal values, pesticide user status, gender, confidence in controlling and certification procedures, and received information. Our results suggest that efforts for risk communication are needed to address food safety issues targeting the general public.

The study investigates Greek consumers’ beliefs and their assessment of the risks associated with consuming potatoes they perceive as contaminated with pesticide residues, aiming to understand the relationship between perceived risk and actual dietary exposure. A survey of 1318 participants was conducted, employing latent profile analysis to identify two distinct consumer profiles: Concerned Consumers, who prioritize certified products and exhibit lower potato consumption, and Confident Consumers, who demonstrate higher consumption levels and lower risk perception. Data from the consumer survey and the two-category grouping were benchmarked against data from the Greek report on pesticide residue monitoring in food to estimate exposure against established toxicological reference values. The results indicate that pesticide residues on potatoes in Greece remain significantly below established toxicological reference values, with mean exposures well within safety limits for both consumer groups. Despite the higher consumption among Confident Consumers, their exposure levels are still negligible. The findings highlight a disconnect between consumer perceptions of pesticide risk and actual exposure, suggesting that current agricultural practices are effective in safeguarding public health. This study underscores the importance of evidence-based risk communication to bridge the gap between consumer concerns and scientific reality, reinforcing the role of potatoes as a safe and essential food source.

The diamide insecticide tetraniliprole is a valuable tool for managing major insect pests like the invasive tomato pinworm, Tuta absoluta (Meyrick). However, the mechanisms underlying tetraniliprole resistance, as well as its associated fitness costs, remain unclear. In this study, we assessed the fitness of tetraniliprole-resistant (TetraRS) and susceptible (SS) strains of T. absoluta and conducted Illumina RNA-seq to compare their transcriptomes. We also used nanocarrier-mediated RNA interference (RNAi) to knockdown P450 genes and evaluate their role in tetraniliprole resistance. After eight generations of selection, T. absoluta developed a 20.80-fold resistance to tetraniliprole, accompanied by fitness costs. RNA-seq analysis revealed 3332 differentially expressed genes (DEGs), with 1707 upregulated and 1625 downregulated in the TetraRS compared to the SS strain. Gene Ontology (GO) annotations showed significant enrichment in categories related to metabolic processes, cellular processes, catalytic activity, cellular anatomical entity, and binding. These genes were also identified in key KEGG pathways such as cytochrome P450, drug metabolism, carbon metabolism, oxidative phosphorylation, fatty acid metabolism, and protein processing. RT-qPCR analysis confirmed that P450 genes (CYP405D1, CYP6AB269, and CYP4AU1) were upregulated in TetraRS insects, in line with the RNA-seq results. Cytochrome P450 activity was significantly higher in the TetraRS strain than in the SS strain. Notably, nano-encapsulated dsRNA targeting these overexpressed P450 genes increased the susceptibility of T. absoluta to tetraniliprole. Further, cytochrome P450 activity was significantly reduced following silencing of P450 genes. These findings suggest that multiple genes and pathways, particularly P450 genes, contribute to tetraniliprole resistance in T. absoluta. This study provides valuable insights into the molecular mechanisms underlying insecticide resistance in this key pest species.

The spirea aphid, Aphis spiraecola (Hemiptera: Aphididae), is a major pest of citrus and other crops, causing feeding damage and transmitting plant viruses. Control relies mainly on insecticides, increasing the risk of resistance. We surveyed Greek populations of A. spiraecola (2022–2023) and developed molecular diagnostics to detect target site mutations linked to resistance against neonicotinoids, carbamates, organophosphates, pyrethroids, and spirotetramat. Seventy-two aphids were analyzed. All individuals were homozygous and susceptible at R81T, A302S, L1014F, M918 variants, and A2226V loci. However, the S431F mutation in the AChE2 gene, associated with resistance to dimethyl-carbamates, such as the selective aphicide pirimicarb, was present in all regions. Heterozygotes occurred at high frequencies, while homozygous resistant individuals were rare. These findings indicate that Greek populations remain largely susceptible to most insecticide classes, but the widespread occurrence of S431F questions the use of pirimicarb in resistance management. The diagnostic assays developed here are cost-effective tools for large-scale monitoring, enabling early detection of resistance in A. spiraecola. Continued surveillance, combined with bioassays and studies on metabolic mechanisms, will be essential for sustainable pest management.

Hydrocarbons play a major role in the life cycle of insects. Their composition and concentration can be affected by several factors. Hydrocarbons are biosynthesized in oenocytes and subsequently transported to the cuticle of insects, such as Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). As the extraction procedure markedly affects the type and amount of hydrocarbon obtained we determined the association between the time taken to extract the maximum amounts of these compounds and the behaviour of D. suzukii. The required extraction time to reach a steady state is different for each hydrocarbon, which in most cases is more than one hour. On the other hand, if the entire hydrocarbon profile of D. suzukii needs to be investigated, extraction times significantly longer than one hour were required. By extending the extraction time 5 additional hydrocarbons were detected in D. suzukii for the first time. One of them, dodecane proved to be repulsive to D. suzukii. In addition, it took 3 h of extraction to determine the maximum value of 9-pentacosene, which is responsible for triggering mating behaviour in D. suzukii.

Wood decay caused primarily by Fomitiporia mediterranea is considered to be an emerging disease for citrus and olive trees in Mediterranean countries. The pathogen cannot be currently controlled by chemicals whereas there is no available information about the source and level of resistance even for the most important cultivars where the global citrus and olive industries are based on. In the present study, five of the most significant Greek olive cultivars (Amfissis, Chalkidikis, Kalamon, Koroneiki and Mastoidis) were evaluated for their resistance to F. mediterranea by conducting artificial inoculation experiments. Disease reactions were evaluated by measuring the length of bark and wood lesions, 33 months post inoculation. Trunk sections scanning and image pixel analysis were employed to estimate the total discoloration and decay area of infected wood, whereas positive re-isolation ratio of F. mediterranea was also taken into account in resistance evaluation. Data on symptom development along with wood tissue colonization by the pathogen indicated that the resistance of olive cultivars to F. mediterranea varied significantly. Based on the cumulative stress response index (CSRI), ‘Kalamon’ and ‘Koroneiki’ were classified as resistant, ‘Chalkidikis’ and ‘Mastoidis’ as intermediately resistant, whereas ‘Amfissis’ was susceptible. Determination of lignin in trunk wood showed that the resistance of olive cultivars to F. mediterranea could be associated with their lignin content. This is the first experimental evidence of differential susceptibility responses of olive cultivars against F. mediterranea, and reveals for the first time the potential exploitation of host resistance as a promising approach in the effort to control wood decay disease of olive in practice.

The use of unmanned aerial vehicles (UAVs) in agricultural pest management has emerged as a promising alternative to conventional methods, particularly in challenging terrains. This study assessed the effectiveness of UAV-based versus ground-based bait spraying for controlling the olive fruit fly Bactrocera oleae in four regions in Greece (Larisa, Zakynthos, Trifillia, and Crete) over a four-year period (2021–2024). In each region, three olive orchards were selected: one received UAV-based bait applications, one was treated using standard ground-based bait application, and the third served as an untreated control. UAV applications were conducted using the M6E hexacopter, while ground treatments followed conventional protocols. Infestation levels were evaluated through systematic fruit sampling, assessing both overall and active infestations. Climatic and orchard data were also recorded to interpret variability in treatment outcomes. Results showed that both UAV and ground treatments significantly reduced infestation compared to the control. Active infestation ranged from 14.2–22.5% in control-untreated plots, 4.6–7.8% in UAV plots, and 5.3–8.4% in ground-treated plots. A significant year × treatment interaction indicated variable efficacy across years, with clearer treatment effects in 2021–2022. UAV applications were as effective or superior to ground spraying, especially in hard-to-reach areas. These findings support the integration of UAVs into pest management programs as a sustainable and efficient alternative for olive fly control.