Revista de la Facultad de Ciencias Agrarias. Universidad Nacional de Cuyo. En prensa. ISSN (en línea) 1853-8665.

Original article

 

Critical Point Analysis for Sustainable Management of Cydia pomonella (Lepidoptera: Tortricidae) in Smallholder Walnut Farms of Catamarca, Argentina

Análisis de Puntos Críticos en la Sustentabilidad del Manejo de Cydia pomonella (Lepidoptera: Tortricidae) en Pequeñas Producciones Nogaleras de Catamarca, Argentina

 

María José Cavallo1,

María Cecilia Castilla1, 2,

Lucas Ariel Barros1, 3,

Oscar Eduardo Romero4,

Braian Vladimir Sosa1,

Martin Sebastian Espinosa5, 6,

Patricia Alejandra Diez1, 5*

 

1Centro Regional de Energía y Ambiente para el Desarrollo Sustentable (CONICET-UNCA). Laboratorio de Control Biológico y Biodiversidad de Insectos. C. P. 4700. Prado 366. Catamarca. Argentina.

2Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Investigaciones de Biodiversidad Argentina. C. P. 4000. Miguel Lillo 251. Tucumán. Argentina.

3Universidad Nacional de Catamarca. Facultad de Ciencias Agrarias. Cátedra Cultivos Industriales. Depto. Producción Vegetal. C. P. 4700. Av. Belgrano 300. Catamarca. Argentina.

4Universidad Nacional de Catamarca. Facultad de Ciencias Agrarias. Cátedra Climatología agrícola. Depto. Clima, Suelo y Riego. Catamarca. Argentina.

5Universidad Nacional de Chilecito. Departamento de Ciencias Básicas y Tecnológicas. C. P. 5360. 9 de Julio 22. Chilecito. La Rioja. Argentina.

6Consejo Nacional de Investigaciones Científicas y Técnicas. C1425FQB. Godoy Cruz 2290. Buenos Aires. Argentina.

 

*diezpatriciaa@gmail.com

 

Abstract

In Argentina, 80% of walnut production is carried out by smallholder farms facing poor technology, production constraints, and substantial economic losses due to pests like Cydia pomonella (codling moth). We assessed sustainability risks linked to phytosanitary management on small farms in the Ambato region of Catamarca, Argentina. Our analysis included a “strong sustainability” framework with three key dimensions: ecological, economic, and sociocultural. A total of 26 indicators were related to this species’ management. Using semi-structured interviews, visual aids, and field surveys across seven farms, an overall sustainability index of 1.521 was calculated, with 50% of the indicators scoring below the established threshold (on a five-level sustainability scale, the selected threshold was level two). The ecological dimension emerged as the most sustainable. Limitations included absent systematic monitoring and optimisation of treatment timing, solely with agrochemical control, weak farmer-to-farmer collaboration, and insufficient training opportunities. Cluster analysis revealed four distinct groups based on phytosanitary practices. This study highlights critical intervention points and suggests agroecological strategies to enhance sustainable pest management in smallholder walnut systems.

Keywords: codling moth, Phytosanitary management, sustainability, Juglans regia

 

Resumen

En Argentina, el 80% del sector nogalero está representado por pequeños productores, con bajo nivel tecnológico, limitaciones en la producción y presencia de especies plaga como Cydia pomonella (“carpocapsa”), entre otros. Se evaluaron los riesgos a la sustentabilidad del manejo fitosanitario de C. pomonella en minifundios de Ambato (Catamarca, Argentina), considerando tres dimensiones: ecológica, económica y sociocultural, bajo un enfoque de sustentabilidad fuerte. Se identificaron 26 indicadores relacionados con el manejo de esta especie. Mediante encuestas semiestructuradas, cartillas visuales y relevamientos en siete fincas, se determinó un Índice de sustentabilidad general de 1.521, con el 50% de los indi­cadores por debajo del umbral establecido (de una categorización de sustentabilidad según una escala de cinco puntos, el valor umbral seleccionado fue de dos). La dimensión ecológica fue la más destacada en términos de sustentabilidad. Las limitaciones encontradas en la práctica fitosanitaria incluyeron la falta de monitoreo de C. pomonella que definan momentos oportunos de control, el uso de agroquímicos como única herramienta de control, ausencia de interacción entre productores y falta de capacitaciones en fitosanidad. Mediante análisis de clúster se evidenciaron cuatro grupos según sus prácticas fitosanitarias. Se detectaron puntos críticos y propusieron herramientas para promover prácticas agroecológicas para un manejo sustentable.

Palabras clave: carpocapsa, manejo fitosanitario, sustentabilidad, Juglans regia

 

Originales: Recepción: 28/02/2025 - Aceptación: 21/07/2025

 

 

Introduction

 

 

Developing sustainable agriculture requires long-term flow of goods and services to meet nutritional, socio-economic, and cultural needs, within biophysical limits defined by the natural system supporting production. Sustainability encompasses multiple, interrelated objectives that demand multidisciplinary approaches (44, 50). Understanding sustainability enables evaluating and mitigating production-based environmental impacts, while accounting for market fluctuations and supply chain vulnerabilities (21). Sustainable systems must be productive, stable, resilient, and adaptable, distributing costs and benefits equitably and fostering autonomous decision-making among stakeholders (3).

Agricultural landscapes are not isolated. Production units and the environment constitute a continuous agroecosystem. Native vegetation refuges natural enemies of insect pests, supporting biodiversity. Ecological services like biotic regulation, nutrient cycling, and pollination must be managed to maintain a dynamic equilibrium between native and introduced components (32). This management depends on farmers’ knowledge and decisions (49).

Walnuts (Juglans regia L.) represent a major agricultural sector in Argentina. Catamarca province ranks second in national walnut production, with 4063 hectares cultivated and 2619.9 tonnes annually (47). The sector comprises a range of production systems, from large-scale farms (20%) to smallholder (80%) (29, 32, 37). These last producers manage fewer than five hectares with limited technological inputs and modest yields. Challenges such as water scarcity, labour shortage, and high logistical costs hinder sustainable practices in the region. Changes in organization of the productive sector related to financing and self-management affect marketing (16).

One productivity constraint is the codling moth (Cydia pomonella (Linnaeus, 1758); Lepidoptera: Tortricidae), a major pest responsible for 40% to 60% yield losses (14). Larvae penetrate fruit after hatching, causing economic damage. Conventional management relies on calendar-based applications of organophosphates and pyrethroids (8), which have led to pest resistance, environmental and biodiversity degradation while risking human health (19). Alternative control strategies, including mating disruption, biopesticides, and parasitoid-based biological control, have not been widely adopted (10, 18, 25).

Transitioning towards sustainable agriculture needs robust methodologies for sustainability assessment. These assessments must be context-sensitive, cost-effective, and capable of identifying critical constraints at different spatial scales (field, farm, region). Since sustainability is a multidimensional concept, it is summarized through indicators (43, 44). In this way, subjective and objective indicators are measured, with the latter recorded independently of what the farmer reports (e.g., vegetation cover). Two main approaches characterize sustainability. Weak sustainability allows substituting natural capital with human-made capital, while strong sustainability sees both as complementary and irreplaceable (15, 21, 38, 43). This work adopted the strong sustainability perspective.

In Catamarca, previous research has addressed data on walnut varietals, types of farmers and biological aspects of C. pomonella (16, 32, 39, 41). To date, one study has assessed sustainability of walnut production, incorporating economic, ecological, and social dimensions within an agroecological framework (24), but no study has dealt with pest sustainable management. This study assessed the risks to sustainable phytosanitary management of C. pomonella by smallholder walnut farmers in Ambato (Catamarca). We employed a set of indicators and semi-structured interviews to evaluate three sustainability dimensions. (a) Ecological: Spontaneous vegetation within walnut crops supports diverse and structurally complex habitats for natural enemies of C. pomonella. (b) Economic: Financial losses from pest damage may exceed profits, compromising economic viability. (c) Sociocultural: Farmers largely operate in isolation and often lack knowledge about pest biology and management strategies.

This multidimensional evaluation provides insights into opportunities and constraints for sustainable pest management in smallholder agroecosystems and proposes future strategies for ecological intensification and rural resilience.

 

 

Methodology

 

 

Study Area

 

 

The study was conducted in the Ambato Department (28°10’14” S, 65°47’29” W) in Catamarca Province, Argentina, where seven smallholder walnut farms were selected as observational units (figure 1). Farms were chosen by considering average walnut production in the area and confirmed presence of C. pomonella. These farms exhibit notable varietal diversity, with predominant traditional ‘Criolla’ seed type and recently introduced lateral-bearing cultivars like ‘Chandler’.

 

Figure 1. Study area. Walnut farms in Ambato, Catamarca, Argentina.

Figura 1. Área de estudio. Fincas de nogales en Ambato, Catamarca, Argentina.

 

 

Indicator Development, Standardization, and Weighting

 

 

Indicators were developed following Sarandón and Flores (2009). Table 1 shows eleven key variables related to phytosanitary management of C. pomonella, each associated with specific response indicators, yielding 26 sustainability indicators (Supplementary Material 1). Each indicator was scored on a five-point ordinal scale, ranging from 0 (least sustainable) to 4 (most sustainable), with 2 as analytical threshold. Relative weights were assigned to each indicator based on its perceived importance within the system. This weighting process was conducted through expert consensus in our research team (Supplementary Material 1).

 

Table 1. Composition of the sustainability analysis of Cydia pomonella management in walnut farms.

Tabla 1. Composición del análisis de sustentabilidad del manejo de Cydia pomonella en fincas de nogales.

* Details of each indicator and its categorization in Supplementary Material 1.

* Detalles de cada indicador y su categorización en Material Suplementario 1.

 

 

Estimation of Subjective Indicators in Economic and Sociocultural Dimensions

 

 

Categorical values of subjective indicators were determined after individual semi-structured interviews with the seven walnut producers between October 2023 and June 2024. The questionnaire comprised 114 questions and was supplemented by two illustrated booklets. These visual materials assessed farmers’ ability to distinguish C. pomonella from other insects like Lepidoptera, Diptera, and Coleoptera, including natural enemies (Supplementary Material 2).

 

 

Estimation of Objective Indicators in the Ecological Dimension

 

 

Field-based ecological assessments were conducted on each farm. These included: (a) Vegetation characterization: number of plant species, cultivated and spontaneous, within each orchard and along field margins during autumn and spring. Species identification was conducted using field guides and images. Particular interest was given to Fabaceae, Asteraceae, and Apiaceae families, known to enhance the presence of natural enemies of C. pomonella (34, 35). (b) Vegetation cover was estimated using the square sampling method (33). Five points per farm were randomly selected, corresponding to cardinal and central sectors (M1: North; M2: East; M3: South; M4: West; M5: center). At each point, 0.25 m² sampling squares were defined. Within these units, species were recorded and vegetation cover was quantified. (c) Proximity to spontaneous vegetation and habitat connectivity considered the distance from ten walnut trees per farm, randomly selected, to the nearest patch of spontaneous vegetation. Mean distance per farm was calculated.

 

 

Data Analysis

 

 

Each farm was treated as an independent unit (20), allowing for in-depth, contextual analysis and extrapolation to the broader regional context. Five categorical sustainability levels assigned to each response identified the most influential sustainability indicators as not sustainable (0%, score 0), weak (25%, score 1), moderate (50%, score 2), optimal (75%, score 3), and strongly sustainable (100%, score 4) (1). A weighted average per indicator was calculated by combining farmer proportion providing each response with the corresponding sustainability score (1, 44). The resulting values were used to generate sustainability profiles by dimension (ecological, economic, sociocultural) for each farm, and to calculate a General Sustainability Index (GSI) for the study area. Farms scoring above the threshold value of 2 were considered optimally sustainable. Equations for indicator weighting, scoring, and index calculation are provided in Supplementary Material 1. Finally, a multivariate cluster analysis (27) grouped farms according to shared indicator profiles, eliminating variables with low discriminatory power. Correlations among farm groups identified patterns of sustainability performance.

 

 

Results and discussion

 

 

Ecological Dimension. Indicator Variability and Biodiversity Management

 

 

Based on farmer-reported data and field measurements, ecological indicators showed the greatest variability among the three evaluated dimensions (figure 2, variables 1-11).

 

Figure 2. Percentage distribution of indicator sustainability based on farmer responses (%). All indicators are related to Cydia pomonella recognition and control.

Figura 2. Gráfico de distribución del porcentaje de sustentabilidad de cada indicador considerando el porcentaje de respuestas de los productores. Todos los indicadores están en función de Cydia pomonella, su reconocimiento y control.

 

Ecological diversity management revealed moderate to high habitat complexity (table 2). Vegetation cover across farms ranged from 45% to 95%, and mean distance to the nearest spontaneous vegetation during spring-summer was under one meter. A total of 29 plant species from 13 botanical families were identified across the farms. However, only 12 of these species belonged to families previously documented as favourable for natural enemies of C. pomonella (23) (table 2).

 

Table 2. Ecological diversity on study farms.

Tabla 2. Diversidad ecológica en las fincas de estudio.

1. Walnut. 2. Quince. 3. Peach. 4. Apple tree. 5. Pear tree. 6. Plum tree. 7. Fig tree. 8. Alfalfa. 9. Almond tree. 10. Barley. 11. Sorghum. 12. Corn. 13. Average percentage of vegetation cover on the farm. 14 Average distance from the walnut tree to the nearest spontaneous vegetation. 15. Number of families. 16. Total number of species. 17. Number of species belonging to the families Fabaceae, Asteraceae and Apiaceae: attractive to natural enemies (EN). 18. Number of vegetation strata.

1. Nogal. 2. Membrillo. 3. Durazno. 4. Manzano. 5. Peral. 6. Ciruelo. 7. Higo. 8. Alfalfa. 9. Almendro. 10. Cebada. 11. Sorgo. 12. Maíz. 13. Promedio de porcentaje de cobertura vegetal dentro de la finca. 14. Distancia promedio del nogal a la vegetación espontánea más cercana. 15. Número de familias. 16. Número de especies total. 17. Número de especies que pertenecen a las familias Fabaceae, Asteraceae y Apiaceae: atractivos para enemigos naturales (EN). 18. Cantidad de estratos.

 

Notable species included Convolvulus arvensis L. (bindweed), Aloysia gratissima G. & H. (whitebrush), Taraxacum officinale L. (dandelion), Melilotus albus M. (white sweet clover), and Ammi visnaga L. (toothpick plant). Notably, plant spatial and temporal distributions do not result from intentional management. Rather, they establish spontaneously, primarily along farm boundaries, which may adjoin other orchards, natural landscapes, or, in some cases, expanding urban zones.

Across farms, vegetation stratification ranged from two to four layers, suggesting a potentially favourable microhabitat structure for natural enemy communities, enhancing biological control potential. Despite this, field observations and expert communications (Engineers Romero and Barros, pers. comm.) indicate low abundance and diversity of natural enemies in the study area, including Goniozus legneri Gordh (Hymenoptera: Bethylidae), an effective parasitoid of several lepidopteran pests, including C. pomonella (5, 10, 31). Several factors may account for this discrepancy. Recent urban expansion in the Ambato Department may have influenced these results (11). This area, formerly dedicated to livestock production, has undergone changes that may have negatively affected soil quality and reduced the availability of potential refuges for natural enemies. The replacement of natural vegetation likely eliminated important sources of food and shelter for beneficial fauna, disrupting the natural landscape and ecological balance. Residual effects of agrochemicals accumulated over recent decades, mainly pyrethroids used for C. pomonella control, could also contribute to these outcomes (6). In this regard, Ferrero and collaborators (2000) demonstrated the detrimental impact of organophosphates and pyrethroids on G. legneri, reporting reductions in longevity, oviposition capacity, and egg-laying size. Similarly, Leyton (2023) documented the harmful effects of several insecticides (Bifenthrin, Pirimicarb, Imidacloprid) on this parasitoid species. Without adequately monitoring pest precise emergence, chemical treatments lose effectiveness, often resulting in repeated applications. Such practices disturb ecosystem balance, reduce functional biodiversity, and compromise long-term ecological sustainability. Moreover, they may contribute to developing resistant pest populations and pose risks to human health.

Walnuts were the primary crop across all farms, accompanied by 11 secondary species, including fruit and forage crops (table 2). A common association was observed with Cydonia oblonga (quince), an alternative host for C. pomonella, with important implications for integrated pest management strategies. However, farmer perceptions of C. oblonga varied. In this study producers generally regarded quince as a low-priority crop, “not needing targeted control measures”. Some even suggested it could constitute a trap distracting C. pomonella away from walnut fruits. This contrasts with Rivero et al. (2012) from Andalgalá (Catamarca), where farmers actively managed C. pomonella in quince to prevent its migration into walnut orchards. These divergent approaches highlight the need for context-specific education on host dynamics and pest ecology.

The weakest ecological sustainability indicator was absent C. pomonella monitoring, essential for understanding population dynamics and their effects on crop yield. Yet, extensive evidence supports the critical role of pest monitoring combined with systematic data analysis, enhancing effectiveness and sustainability of integrated pest management programs (12). Farmers reported not monitoring insects or fruit damage, nor estimating number of damaged fruits per season (figure 2, indicators C10 and C11). This limits timely and effective control strategies.

 

 

Economic Dimension: Sustainability Constraints in C. pomonella Management

 

 

The economic analysis revealed absent monitoring as a major limit for sustainable C. pomonella management. No farmer reported investing in monitoring (figure 2, D12). As a result, chemical control remains predominant across most farms, applied according to calendar schedules and without rotation of active ingredients (figure 2, E13 and E14). This facilitates the emergence of resistant pest populations, already documented in fruit-producing regions like Alto Valle (Río Negro, Neuquén) (12, 48), Chile and South Africa (7, 46). The penetration of neonate C. pomonella larvae into fruit makes post-infestation chemical treatments ineffective. Consequently, pest control must be precisely timed. Monitoring adult population and fruit damage, managing damage thresholds, and tracking degree-day accumulation to anticipate pest emergence have proved most effective (4, 22). However, government-led phytosanitary campaigns often proceed without prior monitoring and on broad-spectrum insecticides applied at high doses, further undermining sustainability. Previous studies in the Andalgalá region have evaluated insecticide use on walnut farms and emphasized the importance of reducing environmental and worker exposure, rotating active ingredients with distinct modes of action, and incorporating at least one compound that preserves beneficial insect populations (8, 9). Despite this, some farms in Ambato report no pest control, citing costly supplies as primary barrier.

Economic losses attributed to C. pomonella (figure 2, F15) are approximately 20% for half of the producers, and between 20% and 50% for the second half, consistent with Andalgalá (42). Only one producer reported losses exceeding 80%. In apple production (Malus domestica), a 1% fruit damage threshold per hectare has been established as economic injury level (13). However, no standardized threshold exists for walnuts. Preliminary research by our group suggests a 4% fruit loss threshold, provided monitoring is conducted regularly (Diez, pers. comm.). These thresholds imply that the sustainability assessment scale used in this study should be adjusted to reflect crop-specific economic realities more accurately, enhancing control relevance.

Alternative cultural and biological strategies remain underutilized. While collecting and destroying infested fruit (e.g., by burning) is recognized as a general pest control practice (36), surveyed farmers reported this approach primarily for land clearing. In addition, the use of corrugated cardboard bands to trap diapausing larvae, a low-cost method to reduce first-generation adult populations (4), is neither considered. Biological inputs, such as C. pomonella granulovirus (CpGV), have shown promising results among traditional growers in Pomán and Andalgalá (40), not yet in Ambato.

Additional economic indicators detected problems related to a lack of productive diversity (figure 2, G16 and G17). Most farms only sell peeled and shelled walnuts in bulk, often at very low prices. Developing value-added products, such as candied walnuts called “nueces confitadas”, walnut oil, or walnut paste, enhances farm income and economic resilience. Similar marketing innovations have been observed in other walnut-growing regions of Catamarca, including Belén and Pomán (field interviews; Poncho Festival 2024, Catamarca).

 

 

Sociocultural Dimension: Insights into Knowledge and Systemic Challenges

 

 

Interview data revealed low sociocultural sustainability risk, as most farmers demonstrated basic knowledge of C. pomonella biology and field behavior (figure 2, H18-H2; table 2). This knowledge is valuable, as sustainable pest control requires understanding the pest’s life cycle and its interaction with the host (2). Participants identified the pest, recognized typical damage signs, and estimated seasonal presence in their orchards. However, as already mentioned, this knowledge is not consistently translated into practice (figure 2, D12, H21, K25). In this context, farmers are unwilling to invest in traps and adopt a passive attitude, expecting the government to provide them. Moreover, they tend to only visually assess crop damage, without conducting actual counts that would evidence precise infestation levels. Additionally, producers did not recognize natural enemies in the brochure (parasitoids and predators). This result contrasts Rivero et al. (2012) in Catamarca, where nearly one-third of the producers recognized parasitoids on their farms.

Regarding alternative host species, only three farmers could identify all potential hosts of C. pomonella, and just one acknowledged the need to manage the pest in those crops (figure 2, H20). Most producers named only one or two hosts, primarily quince (C. oblonga), and believed that C. pomonella affected only walnut trees. Parallel assessments conducted on the same farms indicated that quince trees experienced an average fruit damage rate of 7% during the 2023-2024 season, with peak damage observed in January and February (Ing. Barros, pers. comm.). This gap between knowledge and reality may be linked to limited training opportunities and weak communication between farmers and agricultural institutions (figure 2, J23 and J24). Previous studies have shown that workshops facilitated by technical specialists can strengthen farmer networks and improve pest management outcomes (26, 32).

These findings only partially support our three hypotheses. Ecologically, although habitat structure may favour biological control, actual abundance and diversity of natural enemies seem insufficient. Economically, qualitative data suggest moderate to high pest impact, to be confirmed through quantitative assessments. Finally, socio-culturally, knowledge of the pest is not systematically applied in management decisions. This study diagnoses key limitations in C. pomonella control in Ambato, addressing a gap in the literature and laying the basis for more comprehensive, sustainable pest management in smallholder walnut systems.

 

 

Sustainability

 

 

The average General Sustainability Index (ISg) across the evaluated farms was 1.521, under the established threshold value of 2.0. C. pomonella management exhibited the highest relative sustainability in the ecological dimension (1.663), followed by the sociocultural (1.571) and economic (1.329) dimensions (table 3).

 

Table 3. Indicator values in seven walnut farms in Ambato, Argentina, and general sustainability conditions.

Tabla 3. Valores de los indicadores empleados en siete fincas de Nogales, Ambato, Argentina y condiciones de sustentabilidad general.

1. Walnut farms. A. On-farm diversity management. B. Spontaneous vegetation on farm edges. C. Monitoring and regulation of C. pomonella. D. Economic investment in C. pomonella regulation. E. Chemical control of C. pomonella. F. Economic losses caused by C. pomonella. G. Production marketing. H. Extent of farmer knowledge on C. pomonella, alternative hosts and their regulation. I. Degree of knowledge of agrochemicals for the control of C. pomonella. J. Social role of the farmer concerning C. pomonella management. k. Extent of farmer knowledge on ecosystem services for natural biological control of C. pomonella. 2. Results are averages of the indicators constituting each variable. DE=Ecological Dimension. DK: Economic Dimension. DSC: Socio-Cultural Dimension. ISg: General Sustainability Index. Formula. Supplementary material 1.

1. Fincas de nogales. A. Manejo de la diversidad en la finca. B. Vegetación espontánea en los bordes de la finca C. Monitoreo y regulación de C. pomonella. D. Inversión económica en la regulación de C. pomonella E. Control químico de C. pomonella. F. Pérdidas económicas causadas por C. pomonella G. Comercialización de la producción. H. Grado de conocimiento de los agricultores sobre C. pomonella, hospedantes alternativos y su regulación. I. Grado de conocimiento de los agroquímicos para el control de C. pomonella. J. Rol social del agricultor en relación con el manejo de C. pomonella. k. Grado de conocimiento de los agricultores sobre los servicios ecosistémicos para el control biológico natural de C. pomonella. 2. Los resultados son el promedio de los indicadores que conforman la variable. DE=Dimensión Ecológica. DK: Dimensión económica. DSC: Dimensión Sociocultural. ISg: Índice de Sustentabilidad General. Fórmula. Material suplementario 1.

 

These findings underscore the multifaceted nature of sustainability in pest management. As expected, farms relying exclusively on chemical control did not achieve the highest sustainability scores. In several cases, farms without control practices demonstrated comparable or even higher sustainability indices. This counterintuitive outcome can be attributed to absent monitoring practices across farms, regardless of management intensity. Control measurements without monitoring, particularly chemical applications, are often untimely, excessive, ineffective and economic-ecologically expensive. The absence of integrated monitoring systems constitutes a critical barrier for sustainable pest control.

 

 

Cluster Analysis

 

 

Cluster analysis based on the General Sustainability Index (ISg) identified four distinct groups of farms reflecting sustainability degrees (table 3). Cluster One with the highest sustainability level, comprised only Farm 2, with an ISg of 2.509, surpassing the threshold of 2.0. However, closer examination revealed that this value was driven by higher economic and sociocultural scores, while ecological performance remained limited. The producer demonstrated knowledge of C. pomonella management, including alternative hosts and appropriate agrochemical use. Ecological indicators on this farm revealed sparse vegetation cover, greater distances to spontaneous vegetation, and limited floral diversity from ecologically relevant plant families. At the opposite end, Cluster Two was represented by Farm 5, with the lowest sustainability score (ISg: 0.887). Unlike the other units, this farm’s primary activity is livestock production, with walnut cultivation playing a minor role. Consequently, C. pomonella was not perceived as a significant threat, and no management strategies were implemented. Between these extremes, cluster Three included Farms 4, 6, and 7 (ISg: 1.331, 1.233, and 1.335, respectively), and Cluster Four included Farms 1 and 3 (ISg: 1.654 and 1.698, respectively). These clusters differed primarily in their ecological characteristics. Farms in Cluster Four exhibited higher vegetation cover and greater plant diversity, including flowering species and fruit crops, supporting beneficial arthropod communities. These farmers also reported greater economic losses due to C. pomonella, indicating pest pressure and greater economic dependency on walnut production.

 

 

Conclusion

 

 

This study represents the first assessment of sustainability gaps in the phytosanitary management of C. pomonella among smallholder walnut farmers in Argentina. The findings highlight that effective and sustainable pest control must encompass ecological, economic, and sociocultural dimensions, rather than single-point interventions. To initiate meaningful changes, participatory frameworks must engage all relevant stakeholders, including farmers, academic researchers, and public institutions involved in agricultural policy and extension services. These workshops should be collaborative spaces for knowledge exchange, trust-building, and context-appropriate co-design management strategies. Key prevention must implement systematic pest monitoring and promote ecological practices aimed at regenerating native vegetation and enhancing habitats for natural enemies. Such efforts would strengthen ecosystem resilience and support reestablishing natural biological control mechanisms for C. pomonella. In parallel, enhancing market strategies through value-added products (e.g., processed walnuts, specialty foods) could improve profitability, promote investment in sustainable practices, and increase resilience of walnut production systems. Ultimately, sustainability in smallholder agricultural systems depends on technical improvements in pest control and integration of holistic strategies that align ecological integrity with economic viability and social inclusion. Without adequate profitability, the relative importance of ecological and social factors diminishes, weakening long-term sustainability. Addressing vulnerabilities across all sustainability dimensions (not just one) is essential for effective management of C. pomonella and secure regional walnut production.

 

Acknowledgments

We thank the walnut farmers of Ambato for granting access to their farms and participating in the interviews. We thank Gabriel Reinoso Franchino for assistance in plant species identification, Miguel A. Garlati for general assistance, and Nahuel V. Morales Castilla and Marcos S. Macchioli Grande for language contributions.

This article was proofread by Servicio de Ediciones Científicas de la FCA, UNCuyo, Mendoza.

 

References

1. Abraham, L.; Alturria, L.; Fonzar, A.; Ceresa, A.; Arnés, E. 2014. Propuesta de indicadores de sustentabilidad para la producción de vid en Mendoza, Argentina. Revista de la Facultad de Ciencias Agrarias. Universidad Nacional de Cuyo. Mendoza. Argentina. 46(1): 161-180.

2. Altieri, M. A.; Nicholls, C. I. 2007. Biodiversidad y manejo de plagas en agroecosistemas (Vol. 2). Icaria editorial.

3. Astier M.; López Ridaura, S.; Pérez E.; Masera O. R. 2002. El Marco de Evaluación de Sistemas de Manejo incorporando Indicadores de Sustentabilidad (MESMIS) y su aplicación en un sistema agrícola campesino en la región Purhepecha, México. Agroecología. 415-430.

4. Aubel, A. J. 2022. Estudios de nuevas herramientas de control de plagas de nogales con énfasis en Cydia pomonella en el Valle Inferior del Río Negro. Primera experiencia. Tesis final de Carrera en Ingeniería Agronómica, Facultad de Ciencias Agrarias. Universidad Nacional de Río Negro. Argentina.

5. Barros, L. A.; Espinosa, M.; Romero, O. E.; Carrizo, A.; Cavallo, M. J.; Diez, P. A. 2024. Actualización sobre la presencia natural de Goniozus legneri (Hymenoptera: Bethylidae) en agroecosistemas nogaleros de Catamarca y primer registro en el Departamento Famatina, Provincia de La Rioja. Revista de la Sociedad Entomológica Argentina. 83(3). DOI: 10.25085/rsea.830305.

6. Belles, C.; Cichón, L.; Di Masi, S.; Fernández, D.; Magdalena, C.; Rial, E.; Rossini M. 1996. Guía de pulverizaciones. 72 p.

7. Blomefield, T. 1994. Codling moth resistance. It is here, and how do we manage it? Deciduous Fruit Grower. 44(4): 130-132.

8. Carrizo, A.; Carrasco, F.; Aybar, S.; Leiva, S.; Matías, A. 2015. Estimación del Coeficiente de Impacto Ambiental (EIQ) en diferentes estrategias fitosanitarias en sistemas de pequeños productores de nogal, como una herramienta hacia la transición agroecológica en Catamarca, Argentina. V Congreso Latinoamericano de Agroecología-SOCLA, La Plata.

9. Casado, G. G.; Mielgo, A. A. 2007. La investigación participativa en agroecología: una herramienta para el desarrollo sustentable. Ecosistemas. 16(1).

10. Cavallo, M. J.; Romero, O. E.; Barros, L. A.; Cichón, L.; Garrido, S. A.; Diez, P. A. 2024. Functional and numerical response and mutual interference of Goniozus legneri (Hymenoptera: Bethylidae) on Cydia pomonella (Lepidoptera: Tortricidae): Its implications for biological control. Journal of Applied Entomology. 148(4): 454-463. https://doi.org/10.1111/ jen.13238

11. Censo República Argentina. 2022. Resultados del Censo 2022-Catamarca. https:// censo.gob.ar/ index.php/datos_definitivos_catamarca (Fecha de consulta: 27/11/2024).

12. Cichón L.; Fernández D. E. 1995. TRV Aplicación de volúmenes adecuados en cultivos de frutales de pepita. Ed. EEA Alto Valle.

13. Cichón, L.; Di Masi, S.; Fernández, D.; Magdalena, C.; Rial, E.; Rossini, M. 1996. Guía ilustrada para el monitoreo de plagas y enfermedades en frutales de pepita. Ed. INTA Centro Regional Patagonia Norte. 72 p.

14. Cichón L.; Fernández D. E.; Montagna, M. 2015. Evolución del control de carpocapsa en los últimos veinticinco años. Rev. Fruticultura y Diversificación. 51: 22-29.

15. Daly H. E 1997. De la economía del mundo lleno a la economía del mundo vacío. Ed. Goodland, R. et al. Medio ambiente y desarrollo sostenible. 35-50 p.

16. Errecart, V. 2012. Diagnóstico de la cadena de la nuez de nogal de las provincias de La Rioja y Catamarca. Estrategias y tácticas para mejorar su inserción en el comercio internacional. Tesis de grado de Magister, área Agronegocios y Alimentos. Universidad Nacional de Buenos Aires. Argentina.

17. Ferrero A.; Laumann R.; Gutierrez M. M.; Stadler T. 2000. Evaluación en laboratorio de la toxicidad de insecticidas en Cydia pomonella L. (Lepidoptera: Tortricidae) y en su enemigo natural Goniozus legneri Gordh (Hymenoptera: Bethylidae). Publicación de la Agricultura, Rev. de Sanidad Vegetal. Plagas. 26(4): 559-575.

18. Garrido S.; Cichón L.; Fernández D.; Azevedo C. 2005. Primera cita de la especie Goniozus legneri (Hymenoptera: Bethylidae) en el Alto Valle de Río Negro, Patagonia Argentina. Rev. Sociedad Entomológica Argentina. 64(1-2): 14-16.

19. Gould, F.; Brown, Z. S.; Kuzma, J. 2018. Wicked evolution: Can we address the sociobiological dilemma of pesticide resistance? Science. 360(6390): 728-732. DOI: 10.1126/science. aar378

20. Guzmán Casado G. M.; González de Molina N.; Sevilla Guzmán E. 2000. Métodos y técnicas en Agroecología, Introducción a la agroecología como desarrollo rural sostenible. 5: 149-195.

21. Harte, M. J. 1995. Ecology, sustainability, and environment as capital. Ecological Economics. 15: 157-164.

22. Huerga, M.; San Juan, S. 2005. El control de las plagas en la agricultura argentina. Estudio Sectorial Agrícola Rural-Banco Mundial/Centro de Inversiones FAO-Buenos Aires, Argentina.

23. Iermanó, M. J.; Sarandón, S. J.; Tamagno, L. N.; Maggio, A. D. 2015. Evaluación de la agrobiodiversidad funcional como indicador del potencial de regulación biótica. Aroecosistemas del sudeste bonaerense. Rev. Facultad de Agronomía. La Plata. 114(3): 1-14.

24. Juri, C.; Zárate, L. 2017. Evaluación de la sustentabilidad de una finca nogalera de un pequeño productor en Mutquin - Pomán - Catamarca. Rev. Divulgación Técnica Agrícola y Agroindustrial, Facultad de Ciencias Agrarias - UNCa. 69.

25. Keil S.; Gu H.; Dorn S. 2001. Response of Cydia pomonella to selection on mobility: laboratory evaluation and field verification. Ecological Entomology. 26(5): 495-501. https://doi. org/10.1046/j.1365-2311.2001.00346.x

26. Landini, F. 2022. Intercambio de experiencias y aprendizaje horizontal entre extensionistas: Fuente invisibilizada de conocimientos para la práctica. Psicoperspectivas. 21(3): 7-20. http://dx.doi.org/10.5027/

27. Lê, S.; Josse, J.; Husson, F. 2008. FactoMineR: An R package for multivariate analysis. Journal of statistical software. 25: 1-18. https://doi.org/10.18637/jss.v025.i01

28. Leyton, J. F. 2023. Efectos subletales de agroquímicos sintéticos y naturales contra Goniozus legneri Gordh (Hymenoptera: Bethylidae). Tesis de Magíster en Ciencias Agronómicas. Universidad de Concepción, Chile.

29. López, I.; Lovi, A.; Trejo, J. 2014. Análisis del agregado de valor en la cadena agroalimentaria de la nuez de nogal: caso Establecimiento Finca Don Manuel, Chilecito-La Rioja. Trabajo Final - Áreas de Consolidación, Ingeniería Agronómica. Universidad Nacional de Córdoba, Argentina.

30. Manetti, A.; Lara-Navarra, P.; Sánchez-Navarro, J. 2022. El proceso de diseño para generación de escenarios futuros educativos. Rev. científica iberoamericana de comunicación y educación. 30 (73). DOI: 10.3916/C73-2022-03

31. Marcucci, B.; Mazzitelli, M. E.; Garrido, S. A.; Cichón, L. I.; Becerra, V. C.; Luna, M. G. 2023. Presencia de Goniozus legneri (Hymenoptera: Bethylidae) y su asociación con lepidópteros plagas en el oasis cultivado Norte de la provincia de Mendoza, Argentina. Rev. Sociedad Entomológica Argentina. 82(2): 5-5.

32. Maschio, J. I. 2017. Caracterización de los productores de nogal y su relación con la calidad final del producto en la provincia de Catamarca. Cartilla de divulgación técnica. Revista de Divulgación Técnica Agrícola y Agroindustrial. 76.

33. Matteucci, S. D.; Colma, A. 1982. Metodología para el estudio de la vegetación. Programa Regional de Desarrollo, Científico y Tecnológico. 22.

34. Nicholls, C. 2006. Bases agroecológicas para diseñar e implementar una estrategia de manejo de hábitat para control biológico de plagas. Agroecología. 1: 37-48.

35. Nicholls, C. I. 2008. Control biológico de insectos: un enfoque agroecológico. Ed. Universidad de Antioquia. 282 p.

36. Nievas, W. E.; Rossini, M. N.; Toranzo, J. O.; Iannamico, L. A.; Magdalena, J. C.; Fernandez, D. E.; Curetti, M. 2014. Bacteriosis del nogal (Xanthomonas campestris pv. juglandis) en el Valle Medio del río Negro. Repositorio EEA Alto Valle, INTA. https://repositorio.inta. gob.ar/ bitstream/handle/20.500.12123/16962/INTA_CRPatagoniaNorte_EEAAltoValle_ Nievas_ WE_Bacteriosis_nogal_Xanthomonas_campestris_pv_juglandis.pdf?sequence=1 (fecha de consulta:20/11/2024).

37. Obschatko, E. 2009. Las explotaciones agropecuarias familiares en la República Argentina. Un análisis a partir de los datos del Censo Nacional Agropecuario 2002. Agricultura, Ganadería, Pesca y Alimentos. 68. http://repositorio.iica.int/handle/11324/6860

38. Pearce, D.; Atkinson, G. 1993. Capital theory and measure-ments of sustainable development: an indicator of weak sustainability. Ecological Economics. 8(2): 103-108.

39. Prataviera, A. G. 2000. Problemática del cultivo de la nuez de nogal en las provincias de Catamarca y La Rioja. INTA, Estación Experimental Agropecuaria Catamarca. Informe 4.

40. Quintana, G.; Cólica, J.; Fernández Gorgola, M.; Rivero, C.; Pérez, O.; Luna Mercado L. 2007. Control de Carpocapsa (Cydia pomonella L.) con un producto en base al virus de la granulosis (CPGV), en cultivos de nogal en Catamarca. Rev. CIZAS. 8: 39-48.

41. Quintana, G; Cólica J. 2011. Carpocapsa: plaga clave en nogal. Aspectos morfológicos y biológicos relevantes para un control adecuado. Informe Técnico INTA. 1.

42. Rivero, C.; Cólica, J.; Fernández, G. M.; Cruz, R.; Luna, M.; Rivero, A. R. 2012. El nogal: situación productiva en la localidad de El Potrero, Andalgalá, Catamarca. Rev. CIZAS. 22.

43. Sarandón, S. J. 2002. El desarrollo y uso de indicadores para evaluar la sustentabilidad de los agroecosistemas. Agroecología. 20: 393-414.

44. Sarandón, S. J.; Zuluaga, M. S.; Cieza, R.; Janjetic, L.; Negrete, E. 2006. Evaluación de la sustentabilidad de sistemas agrícolas de fincas en Misiones, Argentina, mediante el uso de indicadores. Agroecología. 1: 19-28.

45. Sarandón, S. J.; Flores, C. C. 2009. Evaluación de la sustentabilidad en agroecosistemas: una propuesta metodológica. Agroecología. 4: 19-28.

46. Sazo, L.; Araya, J. E.; Rodríguez, P. 2006. Evaluación de la susceptibilidad de Cydia pomonella (L.) (Lepidoptera: Tortricidae) al azinfosmetil en Chile. Boletín Sociedad Entomológica Aragonesa. 39: 451-453.

47. Secretaría de Agricultura, Ganadería, Pesca y Alimentos (SAGPyA). 2024. Informe síntesis de la economía regional: nuez del nogal. https://alimentosargentinos.magyp.gob.ar/ HomeAlimentos/ economias-regionales/producciones-regionales/informes/Informe_Nuez_nogal.pdf/ (fecha de consulta 27/12/2024).

48. Soleño J.; Anguiano O. L.; Cichón L. B.; Garrido S. A.; Montagna; C. M. 2012. Geographic variability in response to azinphos-methyl in field-collected populations of Cydia pomonella (Lepidoptera: Tortricidae) from Argentina. Pest Management Science. 68(11): 1451-1457. https://doi.org/10.1002/ps.3327

49. Tamagno, L. N.; Iermanó, M. J.; Sarandón, S. J.; Pérez, R. A. 2014. Influencia de los saberes de los agricultores familiares pampeanos sobre las decisiones productivas y tecnológicas: su relación con un manejo sustentable. Acta IX Congreso Latinoamericano de Sociología Rural. México.

50. Wezel, A.; Gemmill-Herren, B.; Bezner-Kerr, R.; Barrios, E.; Rodrigues Gonçalves, A.; Sinclair, F. 2020. Agroecological principles and elements and their implications for transitioning to sustainable food systems. A review. Agronomy for Sustainable Development. 40: 1-13. https://doi.org/10.1007/s13593-020-00646-z /

 

Supplemmentary material:

https://docs.google.com/document/d/1fVJGbaYYPVGXzDZbZkx76EqjtAr0z1yB/edit?usp=drive_ link&ouid=111310786017351827239&rtpof=true&sd=true

 

Funding information

The study was funded by the Agencia Nacional de Promoción Científica y Tecnológica de Argentina through “Fondo Nacional de Ciencia y Tecnología (FONCyT)” (PICT 2018-02508, PICT 2020-03499 and PICT 2021-00194) and “Fondos Complementarios para proyectos de Investigación con el Impacto en el territorio Argentino 2024 - Fundación Williams”.