Gerardo Arias addressed the integrated management of thrips and mealybugs in blueberries From an applied premise: the biology of the pest should guide monitoring, coverage, timing of intervention and combination of resources in the field.

During his presentation at Blueberries Mexico 2026, the specialist shared experiences developed in Mexico and Peru, with emphasis on strategies that integrate applications, physical barriers, traps, functional biological control, cultural practices and product rotation.

The discussion ordered these measures according to the behavior of each pest, the pressure present in the crop and the real opportunity for intervention.

Integrated management for more precise intervention

Arias opened her presentation with a warning about the increased use of insecticides in regions of the Global South and its link to resistance problems. In the case of Cirthotrips dorsalis, she mentioned reported resistance to various chemical groups and complex control situations in areas such as Sinaloa.

With that diagnosis, he positioned insecticides as one tool within a broader management approach. Their effectiveness depends on integrating monitoring, pest biology, coverage, cultural practices, biological control, and strategic rotation of chemical groups.

This approach helps define what resource to use, when to apply it, and how to combine it with other practices to reduce pressure on buds, shoots, and fruit.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Thrips: biology, kaolin and cover

In the case of Cirthotrips dorsalis, Arias emphasized the importance of understanding its life cycle to better tailor control strategies. This pest has a high reproductive capacity, with females capable of laying between 60 and 200 eggs, and a life cycle that can accelerate under warm conditions.

The specialist explained that the eggs are laid within the plant tissue, the nymphs feed actively, and the prepupal and pupal stages are located in protected, dark, or low-lying areas of the crop. This dynamic allows for different control measures to be applied depending on the stage of the infestation.

Kaolin was presented as a physical tool within integrated pest management. Arias explained that it doesn't directly kill the insect, but rather acts as a barrier that interferes with its feeding and oviposition. In the trials presented, it showed a reduction in oviposition and hatching, always associated with good coverage.

Arias paid particular attention to the underside of the leaf, because that is where most oviposition by Cirthotrips dorsalis typically begins. He also highlighted the use of silicone adjuvants to improve the distribution of contact products and prevent application losses.

The dosage requires operational judgment. In the trials presented, lower doses, when applied correctly, showed results comparable to higher doses, without the problems the latter can cause in application equipment. Based on this, kaolin appears as a useful alternative for delaying establishment and reducing pest pressure, always as part of a broader strategy.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Monitoring and opportunity for intervention

Arias also addressed the use of kairomones, differentiating them from pheromones. He presented them as food attractants that can support mass capture strategies, especially in peripheral areas and in response to adult migrations.

The specialist explained that kairomones are more strategically useful at field edges, where they can help mitigate pest infestations and sudden movements of adult insects. Within the crop itself, the plant's natural volatile compounds have a stronger attraction, making the placement of these alternatives crucial.

Internal monitoring was another key point. Arias highlighted the use of traps to detect initial outbreaks and understand peak flight activity times. In studies conducted in areas such as Ciudad Guzmán, Ciudad Obregón, Los Mochis, and Tapalpa, he observed higher capture rates between 13°C and 33°C.

This information has practical value for contact applications, especially in organic systems or with products that lack systemic or translaminar action. Intervening when adults are most exposed improves the opportunity for contact with the pest and allows for better timing of application.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Beneficial organisms, cultural practices, and entomopathogens

Biological control was approached with a realistic perspective. Arias explained that several beneficial organisms used in other systems, such as some predatory mites or Orius, do not always manage to establish themselves well in blueberriesThis experience reinforces the need to work with resources that are adapted to the growing conditions.

In this context, biological corridors and bank plants can favor the presence of beneficial organisms. Arias mentioned species such as marigold, sunflower, sea lavender, and basil, which are associated with the establishment of predators, pollinators, and fauna useful to the agroecosystem. He also warned that these plants must be managed carefully, since under intensive applications they can become refuges for resistant pests.

Among the benefits observed in blueberryArias highlighted the lacewing, which has become naturally established in the crop. In the studies presented, its larvae showed the ability to prey on nymphs of the Mediterranean fruit fly (Cirthotrips dorsalis), with significant consumption depending on the larval stage. The lacewing can contribute to crop management when utilized as a functional resource within the system.

Cultural practices also played an important role. From flowering onwards, Arias recommended removing young shoots that won't contribute to yield, as these provide favorable conditions for thrips. Reducing these areas helps to decrease conditions for the pest before the fruit becomes more exposed.

In the experiments presented, entomopathogenic fungi emerged as a more targeted alternative when applied to the substrate or the lower part of the crop, where pupae can be found in protected areas. The location of the pupa helps define where to direct the intervention.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Rotation and chemical tools

Arias also reviewed criteria for insecticide use. Rather than focusing the discussion on specific molecules, he emphasized the importance of rotating by IRAC group, considering mode of action, product movement within the plant, compatibility with beneficial insects, target growth stage, and residue limits.

The specialist explained that some products act as contact tools, others have translaminar action, and still others can move within the plant. This difference influences the timing of application, the necessary coverage, and the stage of the pest that the target pest is intended to affect.

He also called for considering compatibility with beneficial organisms and residue limits, especially when evaluating alternatives with systemic movement or applications via irrigation or drench. In his view, chemical control is best integrated when combined with monitoring, kaolin, traps, mulching, cultural management, and functional biological control.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Mealybugs: identification, pruning, and ants

Towards the end of the talk, Arias addressed the management of mealybugs. He clarified that in Mexico it is not yet a widespread priority pest, although local outbreaks exist depending on the area and variety. In Peru, however, it represents a more significant problem, partly due to the proximity of fields of blueberry with grapevines.

The first step, he explained, is correct identification. Pheromone traps can help diagnose which species is present and where the males are located after pruning. This monitoring allows for better planning of subsequent decisions.

In this case, cultural practices also play an important role. Arias recommended removing pruning debris, as some species can leave egg cases with nymphs in plant remains. He also emphasized that the age of the plant and the presence of wood are factors, because mealybugs tend to take refuge in woody structures.

The presence of vineyards in the surrounding area should also be considered, as both crops can share mealybug species. For new plantings, the risk may be lower in the first year, but it increases as the plant develops more wood.

One of the most important points was the role of ants. Arias explained that they can protect the mealybug because they feed on the honeydew it produces, and even move it within the plant. When ants are present, biological control can become less effective. Therefore, managing them becomes part of the overall mealybug control strategy.

The specialist mentioned the use of baits, such as boric acid formulations, to manage ants, in addition to alternatives like wax washing and extracts evaluated during the vegetative stage. These measures complement a strategy that combines identification, monitoring, cleaning, and management of the production environment.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Integrate to protect buds, fruit and production continuity

Gerardo Arias' presentation provided practical guidance for producers and technical teams: thrips and mealybugs require decisions tailored to the state of the pest, the location where it is found, and the timing of each intervention.

This integration allows for reduced pressure, protection of buds and fruit, and sustained production continuity and program adherence with a more consistent strategy over time. In blueberries, integrated management gains strength when monitoring, cover cropping, cultural practices, beneficial fungicides, crop rotation, and timely intervention work together as part of a single strategy.

The value of the talk lay in showing how the biology of the pest can become a practical guide for the field: where to cover, when to monitor, how to intervene and how to sustain management before the health pressure reaches the fruit.

Check out the interview with Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 

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