Beyond exclusion: What growers should consider when facing thrips

For years, thrips have been one of the main concerns for greenhouse growers across Mexico. Their extremely small size, approximately 1.1 mm in males and up to 1.5 mm in females, allows them to go unnoticed with ease. In addition to reproducing rapidly, they can act as vectors of diseases that affect crop quality and yield.

More recently, the detection of Thrips Parvispinus in northwestern Mexico, particularly in Sinaloa, has brought even greater attention to this challenge. While Mexican growers were already familiar with thrips species such as Frankliniella Occidentalis, the arrival of this new species has renewed the conversation around exclusion strategies inside the greenhouse.

The Challenge Is Not Just About Excluding Insects

Thrips represent a significant threat because they can damage leaves, flowers, and fruit while also contributing to the spread of diseases that affect crop quality and productivity.

At the same time, growers are facing an increasingly complex reality. Pest pressure can vary depending on the region, local climate conditions, and the crops grown around the greenhouse. In some cases, chemical control alone is no longer enough, or it may face increasing restrictions.

As a result, insect exclusion nets have become an important part of an integrated climate management strategy. However, when the goal is to exclude insects as small as thrips, another question naturally comes ups: What happens to the greenhouse climate when we reduce the size of the holes in a net?

When airflow changes, greenhouse climate changes

Air movement plays a fundamental role inside the greenhouse. It helps remove excess heat and contributes to creating more stable growing conditions. In addition, insect nets can also influence humidity levels inside the greenhouse. In some dry regions, they help retain humidity, which can be beneficial for the crop.

For this reason, exclusion decisions should not be evaluated only by their ability to keep insects out.

When ventilation is reduced, heat and water vapor have a harder time leaving the structure. In regions such as Guanajuato, Jalisco and Michoacán, where temperatures can remain high for much of the year, this can lead to greater heat accumulation and less air movement within the crop. What started as a decision to improve insect exclusion can also influence the conditions plants experience inside the greenhouse.

In crops such as peppers and cucumbers, these factors can directly affect crop development and fruit quality. That is why insect protection and climate management should be part of the same conversation.

The Best Decision Depends on the Entire System

One of the most important conclusions is that there is no single solution that works for every grower.

The answer will be different for every operation and depends on factors such as:

• Thrips pressure in the area
• The crop being grown
• Local climate conditions
• The type of greenhouse
• Available ventilation

In practice, growers do not make decisions about pests and climate separately. Both are connected, and understanding that relationship makes it easier to evaluate the impact of any change inside the greenhouse.

Looking beyond the pest

New pest challenges have brought thrips back to the center of many technical discussions. However, experience from greenhouses in different regions shows that success does not depend only on keeping insects out.

The recent arrival of Thrips parvispinus is an example of how pest pressure continues to evolve. What works against one pest today may need to be adjusted tomorrow as new species emerge, pressure levels change, or growing conditions shift. Rather than looking for a single solution, it is becoming increasingly important to understand how crops, climate, and exclusion strategies interact inside the greenhouse.

It also depends on maintaining conditions that allow crops to develop consistently throughout the production cycle.

Decisions related to exclusion also influence the airflow, temperature, and humidity that crops experience every day.

Ultimately, protecting a crop is not only about keeping certain insects out of the greenhouse. It is also about creating conditions that help plants grow and perform throughout the entire production cycle.