DNA methylation is an epigenetic mechanism involved in plant defense, yet its role in insect resistance remains unclear. Although herbivory remodels plant methylomes, the links between DNA methylation, resistance traits, and phytohormone signaling remain unresolved. We induced genome-wide hypomethylation in potato plants, Solanum tuberosum L., using the DNA methyltransferase inhibitor 5-azacytidine (5-azaC), and assessed their resistance to the potato tuber moth (PTM), Phthorimaea operculella Zeller. Foliar application of 100 μm 5-azaC significantly reduced global DNA methylation in leaves and compromised resistance to Phthorimaea operculella. Larvae and adults displayed stronger feeding and oviposition preferences, respectively, for 5-azaC-treated plants and larvae gained 25.9% more weight on treated than on control plants. These dual defects were associated with marked decreases in trypsin proteinase inhibitor (TPI) accumulation and emission of the anti-herbivore volatiles such as β-caryophyllene. Moreover, hypomethylated plants had substantially lower levels of jasmonic acid (JA) and transcripts of JA biosynthetic genes. Exogenous methyl jasmonate (MeJA) restored resistance to Phthorimaea operculella by reinstating TPI accumulation and β-caryophyllene emission, whereas silencing of allene oxide cyclase gene (StAOC) caused opposite phenotype. Moreover, JA modulated genome-wide DNA methylation during herbivory and Phthorimaea operculella herbivory reduced promoter methylation of JA-related genes. Disrupting DNA methylation homeostasis compromises potato defenses and is associated with reduced JA-regulated defense outputs. Our findings reveal dynamic interplay between DNA methylation and JA-mediated herbivore defense in potato. © 2026 Society of Chemical Industry.

RNAi against ribosomal protein L27 gene impairs larval development in Phthorimaea operculella

The potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is a major constraint on commercial potato production worldwide. Larvae damage plants by mining the foliage and penetrating tubers, thereby rendering them unmarketable. In the present study, the effects of six potato cultivars (Agria, Fontane, Javid, Jelly, Marfona, and Sprit) on the life table parameters and feeding efficiency of P. operculella were evaluated under controlled laboratory conditions. Data were analyzed based on the age-stage, two-sex life table method. In parallel, we examined biochemical traits associated with host susceptibility and quantified protein, starch, flavonoid, and phenolic contents to evaluate their relationships with the ecological performance and nutritional indices of the pest. The results indicated that P. operculella exhibited the shortest developmental period when reared on Fontane, Marfona, and Sprit, whereas the longest development time was observed on Agria. The Javid cultivar supported the highest intrinsic rate (r) and finite rate of increase (λ), while Agria and Marfona resulted in the lowest values for these parameters. The highest relative growth rate (RGR) was recorded on Fontane, Javid, and Sprit, whereas Agria yielded the lowest RGR. Correlation analyses revealed a positive association between tuber starch content and both developmental duration and net reproductive rate (R₀). In contrast, phenolic content was negatively correlated with R₀ and r. Cluster analysis classified Javid as a relatively susceptible cultivar, while Fontane, Sprit, and Marfona were identified as comparatively more unsuitable to P. operculella population growth. Overall, these findings provide valuable insights into host plant-pest interactions and can contribute to the development and refinement of integrated pest management (IPM) strategies against the potato tuber moth.

Phthorimaea operculella is a globally distributed pest of solanaceous crops and represents one of the most critical constraints on potato production worldwide. The overuse of chemical insecticides has led to widespread resistance in pest populations, making entomopathogenic fungi a promising alternative strategy for sustainable agricultural pest management. In this study, a fungal strain designated ML-2 was isolated from naturally infected P. operculella larvae collected from a potato field in Yunnan province, China. Through morphological characteristics and ITS sequence analysis, strain ML-2 was identified as M. robertsii. The growth rate and sporulation yield on PDA and SDAY media were assessed, the virulence of ML-2 against eggs, larvae, and pupae of P. operculella were determined using the dipping method, and the data were analyzed via the time-concentration-mortality (TCM) model. The results showed that there were no significant differences in the growth rate of strain ML-2 on the two culture media (p > 0.05), whereas the sporulation yield on PDA medium was significantly higher than that on SDAY medium (p < 0.01). The highest corrected cumulative mortality rates for P. operculella larvae and pupae were 94.50% and 83.07% on day 7 after inoculation, respectively, while the highest cumulative mortality rate for eggs was relatively low at only 20.28%. Additionally, at a concentration of 1 × 108 spores/mL, the LT50 values of strain ML-2 against P. operculella larvae and pupae were 2.34 days and 2.72 days, respectively. On day 7 post-inoculation, the LC50 values for larvae and pupae were 3.24 × 107 conidia/mL and 9.64 × 105 conidia/mL, respectively. In conclusion, M. robertsii ML-2 exhibits high potential as a candidate biopesticide and can be used in the sustainable integrated management of P. operculella.

ABSTRACT Host fidelity in phytophagous insects can arise from both genetic constraints and behavioral plasticity, with consequences for host specialization. The preference–performance hypothesis predicts that females should oviposit on hosts that maximize offspring fitness, yet the extent to which host fidelity and host quality jointly shape oviposition preference is not fully understood. For host fidelity to be an adaptive pattern, it should be relaxed in scenarios of low‐quality hosts. We used the potato tuber moth Phthorimaea operculella (PTM) to test if fidelity to a given host depends on its quality as larval host. First, PTM larvae were reared on seven potato ( Solanum tuberosum ) varieties differing in dry matter content. We measured performance parameters, including larval stage duration, pupal weight, and pupal survival. We found variation in PTM performance across potato varieties, which was aligned with the varieties dry matter content. Larval development was fastest and pupal numbers highest on the high‐dry matter (starchy) varieties, while pupal weight varied among varieties and did not consistently align with host quality. Based on the performance results, we chose one potato variety representing each of three categories of host quality: low (waxy), high (starchy) and intermediate (waxy‐starchy). Second, we evaluated in a four‐port olfactometer the oviposition preference of gravid females reared on each of those three varieties of different quality, having as alternative choices the same three varieties plus a control variety. Females reared on high‐quality and intermediate‐quality varieties strongly preferred their rearing host, that is, showed host fidelity. In contrasts, those females reared on a low‐quality variety showed no preference. Results show that host fidelity in PTM is conditional on host quality and shaped by developmental experience, supporting the preference–performance hypothesis when hosts are of relatively high quality only. Our findings have implications for the evolution of host specialization in insects and PTM management.

Predator-derived chemical cues suppress pest reproduction through non-consumptive pathways and may be exploitable as semiochemicals in integrated pest management. We evaluated the volatile organic compounds (VOCs) emitted by the predatory mite Pyemotes zhonghuajia, for their inhibitory effects on reproduction in the potato tuber moth (Phthorimaea operculella, PTM). Screening of 34 mite-associated VOCs identified dimethyl trisulfide (DMTS) as the strongest oviposition suppressor. In dose-response assays, DMTS reduced egg-laying (>80% at 0.9 mg mL-1), shortened the oviposition period (from 5.09 to 1.86 days at 0.9 mg mL-1) and decreased female longevity (from 13.48 to 4.80 days), but did not affect the pre-oviposition period. DMTS exposure also lowered mating frequency without affecting copulation duration, thereby compounding fecundity reduction. Offspring from exposed parents hatched slightly earlier (4.00 versus 4.32 days), showed prolonged larval development (14.44 versus 13.61 days), and exhibited higher food consumption (1.66 versus 0.83 g). Ovarian dissections revealed fewer mature oocytes, consistent with inhibited oocyte maturation. DMTS disrupts PTM reproduction by suppressing oviposition and mating, and inhibiting ovarian maturation, with additional, modest carry-over effects on offspring development. These findings support DMTS as a promising predator-derived semiochemical for sustainable PTM management. © 2026 Society of Chemical Industry.

Infestation of potato by the potato tuber moth (Phthorimaea operculella) varies markedly among cultivars, yet the chemical and molecular mechanisms underlying this variation remain poorly understood. Here, we combine field surveys, chemical ecology, functional genomics, and structural modeling to reveal how cultivar-specific volatile profiles shape moth oviposition behavior and pest outcomes. Field and laboratory assays identified marked differences in adult attraction, oviposition, and larval damage among potato cultivars, which correlated with distinct blends of emitted volatile organic compounds (VOCs). Behavioral analyses revealed that among other VOCs, trans-nerolidol and β-ionone act as attractants, whereas 3-carene and benzyl tiglate function as oviposition deterrents. Electrophysiological screening and heterologous expression deorphanized six female-biased odorant receptors (ORs), identifying three narrowly tuned receptors linked to cultivar susceptibility or resistance. PopeOR01, upregulated following mating, selectively detects the attractant trans-nerolidol, which is enriched in susceptible cultivars, whereas PopeOR15 and PopeOR73 are tuned to repellents benzyl tiglate and 3-carene, respectively, which are enriched in resistant cultivars. CRISPR/Cas9-mediated knockouts confirmed that PopeOR01 and PopeOR73 are essential for antennal detection and behavioral responses to their cognate ligands. AlphaFold3 modeling, molecular docking, and molecular dynamics simulations revealed conserved OR-Orco channel architecture and stable ligand-binding modes consistent with physiological and behavioral data. Together, our results establish a mechanistic link between potato cultivar chemistry, insect olfactory receptor function, and pest behavior, providing a molecular framework for sustainable, semiochemical-based management of the potato tuber moth.

The potato tuber moth (PTM), Phthorimaea operculella (Zeller), is a globally significant pest that attacks potatoes and many other Solanaceous crops. The ectoparasitic mite Pyemotes zhonghuajia Yu, Zhang & He is a promising biological control agent for PTM. This study investigated the effects of PTM larval body size (small and large) and P. zhonghuajia density (50, 150, and 250 mites) on host paralysis, as well as on the development and reproduction of P. zhonghuajia, aiming to optimize its mass production and application in PTM management. Our results showed that P. zhonghuajia females took significantly longer to paralyze and kill large PTM larvae at the lowest density (50 mites). Increasing mite density significantly decreased the parasitism rate per host, likely due to increased mutual interference among host-searching mites. However, the number of P. zhonghuajia females feeding on a single host increased significantly with mite density, resulting in smaller opisthosoma and fewer offsprings, suggesting food competition among females. Host size had a significant positive effect on opisthosoma size, offspring number per opisthosoma, and total offspring produced by P. zhonghuajia female, indicating that larger hosts provide more nutrients. The total number of offspring produced by P. zhonghuajia females from a host of a given size was similar across mite densities, suggesting that an optimal ratio of 50 P. zhonghuajia females per PTM larva is recommended for laboratory mass rearing and field augmentative release.

Leveraging green synthesis of ZnO-NPs for improved potato resistance against Phthorimaea operculella

Understanding the relationship between the parasitism characteristics, development, and reproduction of parasitoids and host age is crucial for effective pest biocontrol. To optimize the biological control strategy of the potato tuber moth (PTM), Phthorimaea operculella, the parasitic behavior, host preference, offspring fitness, and glasshouse efficacy of a natural Trichogramma chilonis strain on PTM eggs of different ages were assessed. Trichogramma chilonis successfully parasitized PTM eggs aged 24-108 h, but behavioral acceptance rate decreases significantly with increasing age. Younger eggs (24 h) were examined more quickly, while drilling and oviposition times were unaffected by age. In choice tests, T. chilonis preferred eggs aged 72 h or less, with no significant preference found in no-choice tests. Notably, offspring fitness was significantly reduced when parasitizing older eggs (96 h). Compared to T. chilonis offspring obtained from parasitizing 72 h eggs, those developing from 96 h eggs exhibited a 58.69% decrease in emergence rate and a 21.97% reduction in fecundity. Furthermore, the offspring were also smaller in size. Female body length, head width, and hind tibia length decreased by 8.88%, 10.27%, and 12.97%, respectively, with corresponding reductions in males were 6.11%, 8.39%, and 5.24%. Glasshouse trials further confirmed that T. chilonis parasitizes PTM eggs on plants, reducing emergence of PTM adults by 47.78%. Trichogramma chilonis perform best on 24-72-h-old PTM eggs, and oviposition preference exhibits behavioral plasticity. This reveals the host-use pattern and oviposition strategy linked to offspring performance in T. chilonis, providing implications for its application in the biological control of PTM. © 2026 Society of Chemical Industry.

The efficacy of cry genes in different plant species is critical for the design and implementation of stewardship plans targeting resistance to polyphagous insects in multiple crops. Transgenic plants of three solanaceous species: Nicotiana tabacum L. (tobacco), Solanum aethiopicum L. (scarlet eggplant), and Solanum tuberosum L. (potato) were therefore transformed using the same binary vector with a cry 1Ac9 gene and assessed in bioassays against the same population of potato tuber moth (PTM; Phthorimaea operculella ). The insect resistance conferred by the cry 1Ac9 gene differed markedly among the three plant species. The cry 1Ac9 gene was most effective in scarlet eggplant, with all four transgenic lines exhibiting high mortality of neonate PTM larvae (60%–100% mortality) and very low mean larval growth index. All 24 transgenic lines of tobacco produced significantly reduced mean larval growth indices, with 50% of the lines exhibiting 7%–33% mortality. Among the 119 transgenic potato lines from six cultivars the mean larval growth indices were substantially higher, with only 85% exhibiting significant growth inhibition. No larval mortality was observed on the transgenic potato lines. The findings have important implications for managing polyphagous insect pests when the same cry gene is deployed in multiple crops.

The extensive reliance on synthetic pesticides has led to considerable ecological disruption and negative impacts on non-target organisms worldwide. As a sustainable alternative, nanotechnology offers promising avenues for the development of innovative and environmentally safe biopesticides. In this study, the insecticidal efficacy of ethanol and silver nanoparticles (AgNPs) extracts derived from Lantana camara L. was evaluated against the eggs and larvae of the Potato Tuber Moth (Phthorimaea operculella [Zeller, 1873]), a quarantine pest of major concern in potato production in Türkiye. Toxicological assessments revealed dose-dependent larvae mortality, with LC₅₀–LC₉₀ values ranging from 6.49–51.45 ppm for ethanol extracts and 1.47–5.88 ppm for AgNPs formulations. Maximum inhibition of egg hatching was observed at 12% ethanol extract (86.51%) and 200 ppm AgNPs treatment (94.95%). Bioassay results demonstrated that AgNPs formulations of L. camara were significantly more effective than ethanol extracts in suppressing both larval and egg development. Moreover, potato tubers treated with AgNPs exhibited a pronounced reduction in adult moth emergence compared to untreated controls. Collectively, these findings highlight the potential of L. camara nano-silver extracts as a sustainable biopesticide candidate for integrated management of P. operculella.

Postharvest losses caused by potato tuber moths severely impact storage in the Andean highlands, where reliance on synthetic insecticides poses sustainability and safety concerns. This study evaluated eco-friendly alternatives for protecting stored seed tubers of the widely adopted cultivar INIA 302 Amarilis in Cajamarca, Peru. In two storage facilities, a completely randomized block design compared four treatments: Bacillus thuringiensis plus talc (Bt-talc), talc, agricultural lime, and wood ash against an untreated control. Powders were applied at 50 g per 10 kg of tubers, and incidence, severity of damage, and live larvae were assessed over 150 days. Bt-talc consistently achieved the lowest damage. Incidence in Cochapampa was 16.8% ± 6.2 with Bt-talc, compared with 58.1% ± 3.9 in the control; in Sulluscocha, incidence was 25.5% ± 4.8 and 64.2% ± 3.0 for Bt-talc and the control, respectively. A similar pattern was observed for moth-damage severity in both localities. Live larvae per unit were also markedly lower with 1.3 ± 0.3 (Cochapampa) and 1.6 ± 0.6 (Sulluscocha) under Bt-talc. A single dusting with Bt-talc, or alternatively agricultural lime, offers effective, accessible, and sustainable control of potato tuber moths in high-Andean storage.

Tecia solanivora (The Guatemalan potato tuber moth) is a major potato pest, responsible for up to 20% of crop losses and a significant economic impact. Certain Pseudomonas exhibit insecticidal activity and produce virulence factors with cytotoxic and antimicrobial properties, positioning them as promising candidates for biological control. This study evaluated seven Pseudomonas strains with insecticidal activity and identified key virulence factors involved. The strains demonstrated varying degrees of insecticidal activity, with Pseudomonas protegens strains CHA0 and 59C being the most lethal, causing over 75% mortality and triggering a systemic melanization response in the insects. Genomic analysis revealed 175 virulence-related genes shared across all strains and 16 genes specific to the highly insecticidal ones, including genes for antimicrobial compounds and insect toxins. Mutational analysis confirmed the roles of hydrogen cyanide, 2,4-diacetylphloroglucinol, pyoluteorin, Fit toxin, and two-partner secretion systems in P. protegens CHA0 insecticidal activity. This strain also exhibited insecticidal effects on adult T. solanivora and delayed egg hatching and pupal emergence. In microcosm assays, P. protegens CHA0 reduced tuber damage caused by T. solanivora larvae by up to 38%. These results suggest that P. protegens CHA0 is a promising biocontrol agent, providing a sustainable alternative to chemical pesticides to control T. solanivora.

The ectoparasitic mite Pyemotes zhonghuajia is a promising biological control agent that rapidly immobilizes and exploits insect hosts via venom-mediated mechanisms. To clarify how parasitism alters host physiology, we quantified water content, lipid, protein and glycogen dynamics in fourth-instar larvae of the potato tuber moth Phthorimaea operculella over 1–7 days following exposure to gravid female mites. Parasitized moth larvae experienced rapid dehydration beginning on day 2 and reached ~60% cumulative water loss by day 6, whereas mites maintained a stable internal water content of ≈72%. Host lipid content increased sharply after parasitism, peaking at 59% on day 3 (control: ~27%). Host protein concentration rose progressively from day 2, reaching 1.67 ± 0.04 µg·µL⁻¹ at day 7, while host glycogen showed minor fluctuations with a transient peak at day 6. In contrast, Py. zhonghuajia showed early increases in lipid and protein during progeny development and a rapid depletion of glycogen after day 1. These results indicate that Py. zhonghuajia induces a coordinated metabolic reconfiguration in Ph. operculella, characterized by rapid host desiccation, lipid mobilization and protein upregulation, changes that are consistent with optimized nutrient extraction to support mite reproduction.

Postharvest losses from potato tuber moth severely constrain seed quality in Andean smallholder systems. This study evaluated four locally available repellent plants-Ambrosia peruviana, Eucalyptus globulus, Artemisia absinthium, and Minthostachys mollis-applied as dried leaves layered within seed bags of INIA 302 'Amarilis' under farmer-like storage at two highland sites in Cajamarca, Peru (Huaytorco, 3350 m; Samaday, 2750 m), over 187 days. Within each site, a Completely Randomized Design with three bag-level replicates per treatment was used, and damage was assessed after 187 days as incidence of attacked tubers, internal damage severity and live larval counts. Endpoint data were analyzed separately by site using Kruskal-Wallis tests followed by Dunn's post hoc test with Šidák correction (α = 0.05). Across both sites, all botanicals significantly reduced damage severity and live larval counts relative to the untreated control. At the warmer, lower site, A. absinthium and M. verticillata achieved large effect sizes, with severity and larval numbers reduced by roughly 80-90% compared with the control, while at the cooler, higher site, larvae were not detected in any botanical treatment. These findings indicate that simple layering of dried leaves from locally available plants, particularly wormwood and muña, can substantially mitigate S. tangolias damage in highland seed potato stores and represents a promising, low-cost complement to integrated pest management, although multi-season and dose-response studies are still needed to confirm and refine this approach.

The intricate ecological interplay between predators, prey, and parasitoids is a key determinant of ecosystem dynamics. This study investigates the non-consumptive effects of the mite parasitoid Pyemotes zhonghuajia on the potato tuber moth (PTM) Phthorimaea operculella, revealing complex responses within the framework of the 'ecology of fear'. The results show that PTM exhibits accelerated development and a shortened lifespan in the presence of P. zhonghuajia, particularly during the larval stage. Additionally, parasitoid exposure significantly impacts PTM's reproductive parameters, leading to reduced fecundity. Gas chromatography-mass spectrometry (GC-MS) analysis identified 34 volatile compounds emitted by P. zhonghuajia. Electroantennography (EAG) recordings revealed that PTM antennae responded to most of these volatiles, with males generally exhibiting higher sensitivity than females. In Y-tube olfactometer bioassays, females showed no behavioral response to any of the tested compounds, whereas males were attracted to decanal, 2-undecanone, nonanal, tetramethylpyrazine, and trimethylpyrazine. These fear-induced responses underscore the delicate trade-off between survival and reproduction in host species facing parasitism risk. The study highlights the ecological implications of such fear-driven alterations in host life history traits and olfactory behavior. Furthermore, the findings provide valuable insights into the potential application of P. zhonghuajia as a biocontrol agent against PTM. Understanding these mechanisms contributes to the development of sustainable integrated pest management (IPM) strategies, promoting ecologically balanced pest control in agroecosystems. © 2025 Society of Chemical Industry.

The increasing challenges of pesticide resistance and environmental harm highlight the need for innovative plant-based crop protection strategies. This study investigated the potential of prohydrojasmon (PDJ), a synthetic jasmonate derivative that is primarily used as a growth regulator, to enhance plant resistance against specialist (Phthorimaea operculella Z) and generalist (Thrips tabaci) herbivores in potato (Solanum tuberosum L.). We examined the effects of exogenous PDJs on plant growth, herbivore performance, insect host preferences, volatile organic compound (VOC) emissions and defense-related gene expression. Our results revealed that PDJ treatment reduced herbivore feeding damage, survival and oviposition in a dose-dependent manner without compromising plant growth or physiological parameters. Remarkably, PDJ treatment simultaneously enhanced the attraction and efficiency of P. operculella eggs parasitoid, Trichogramma chilonis ishii and thrips predator, Orius insidiosus Wolff. Substantial increases in defensive VOCs, particularly β-caryophyllene, copaene and 3-carene, were found upon PDJ treatment. Y-tube olfactometer assays confirmed that these VOCs effectively repelled herbivores while attracting their natural enemies. Furthermore, PDJ treatment strongly up-regulated the jasmonic acid biosynthesis genes (StAOS, StAOC) while down-regulating salicylic acid pathways genes (StEDS1, StNPR1). This study sheds light on the use of PDJ as a promising elicitor for integrated pest management, capable of enhancing direct and indirect herbivore defense mechanisms in potato without fitness costs, offering an environmentally sustainable approach to crop protection. © 2025 Society of Chemical Industry.

Abstract Irish potato ( Solanum tuberosum ) is an important food and cash crop for smallholder farmers in Tanzania, particularly in the Southern Highlands. Despite these, yields remain low due to persistent challenges from pests and diseases, threatening both productivity and household incomes. This study examined knowledge, perceptions and practices of smallholder farmers in managing pests and diseases of Irish potato in Mbeya, Tanzania. A total of 225 farmers from five wards were surveyed using structured interviews and focus group discussions. Most respondents (83%) identified pests and 73% identified diseases as major constraints. Aphids (83%), whiteflies (71%) and potato tuber moth (39%) were the most commonly reported pests, while early blight (91%), late blight (45%) and Fusarium wilt (29%) were the most cited diseases. Despite the widespread use of chemical pesticides (92%) and fungicides (72%), access to these inputs was constrained by high costs, limited availability and insufficient knowledge, with only 24% of farmers reporting effective use. Non-chemical methods, such as crop rotation, intercropping and botanical extracts, were rarely practiced, reflecting low awareness and limited extension support. Most farmers relied on experience rather than consulting agricultural officers, and over 90% used traditional seed varieties. Yields varied significantly among wards, with averages ranging from 1.1 to 22.4 t/ha. While farmers demonstrated awareness of pests and diseases, management practices were heavily dependent on synthetic chemicals, with minimal integration of sustainable strategies. These findings highlight the need to promote integrated pest and disease management approaches tailored to local conditions for improving productivity of Irish potato.

As the third most important global food crop, potato plays a vital role in ensuring food security and poverty alleviation. However, its production is severely threatened by the potato tuber moth (Phthorimaea operculella; PTM), a destructive pest that damages foliage during growth and bores into tubers during storage, causing yield losses of 85-100% under severe infestations. Traditional reliance on chemical pesticides poses challenges such as environmental pollution, pesticide residues, and increased production costs, highlighting the need for sustainable alternatives. In this study, Cry1C and Cry2A genes were expressed in potato cultivar E3 via Agrobacterium-mediated transformation, generating single-copy transgenic lines with high gene expression. Bioassays showed that PTM larvae feeding on transgenic leaves exhibited significantly elevated mortality (>35.4%), with the Cry1C-2 line achieving 60.4% mortality within 24 h. Notably, the highest-expressing Cry1C and Cry2A transgenic lines caused 100% larval mortality within 4 and 7 days, respectively, demonstrating complete lethality against PTM. Histological analysis confirmed that Bt proteins induced midgut epithelial cell lysis and peritrophic membrane disruption, directly leading to insect death. This study is the first to demonstrate that Cry2A expression in potato confers resistance to PTM. It provides novel genetic resources for insect-resistant potato breeding and proposes a gene pyramiding strategy to delay the onset of resistance evolution in pest populations. Future research should focus on evaluating field resistance durability and investigating potential synergistic effects between Cry1C/Cry2A and other Bt proteins to develop multi-target pest management systems. © 2025 Society of Chemical Industry.