A recent scientific study has unveiled significant differences in the bacterial communities inhabiting the scale insect between the regions of Al Hoceima and Marrakech. Moroccan researchers are optimistic that these findings could pave the way for developing effective strategies to combat the pest, which has caused extensive damage to cactus cultivation in the country since its emergence over a decade ago.
Published in the journal "Frontiers in Microbiology", the study demonstrates that the insects collected from Al Hoceima harbor a greater bacterial diversity compared to those from Marrakech. This is evident in both the intestines and ovaries of adult females, as well as in the nymphs. The researchers’ intent extends beyond merely cataloging the bacteria; they aim to ascertain whether specific microorganisms aid the scale insect in feeding, growth, or reproduction. Disrupting these interactions could potentially offer a new avenue for pest control in the future.
Researchers from Mohammed VI Polytechnic University gathered samples from various locations including Ait Hicham, Tamassint, and Tla Youssef in Al Hoceima, alongside samples from three sites in Marrakech. They conducted genetic analyses to identify the bacterial species present within the insects. The team selected two regions with contrasting climatic conditions—Al Hoceima, characterized by a more humid Mediterranean climate, and Marrakech, which experiences a drier climate—to explore the relationship between environmental factors and the bacterial composition of the pest.
The genetic tests yielded approximately 2.84 million readings, revealing that the Al Hoceima samples are richer in bacterial species, with notable differences in the dominant groups between the two regions and at various growth stages of the insect. This disparity is significant as numerous insects rely on internal bacteria that support vital functions. Consequently, the researchers are keen to transition from merely understanding "who lives inside the insect" to determining "what they do there".
For instance, if it is discovered that certain bacteria facilitate the scale insect's acquisition of nutrients it cannot independently obtain or enhance its reproductive capacity or environmental resilience, targeting these bacteria could potentially undermine the pest's viability. However, it is crucial to note that the study has not yet provided a definitive treatment for the cactus, nor has it established that the identified bacteria are responsible for the insect's spread. The researchers emphasize the necessity for functional studies to clarify the role of each bacterial species identified.
These findings emerge as Morocco continues its efforts to reclaim cactus fields lost since the scale insect invaded the Sidi Bennour area in 2014, subsequently spreading to other production regions. The pest thrives on the plant in dense colonies, extracting its sap, which leads to yellowing, wilting, and eventual death of the plant under severe infestation. Its spread has significantly impacted a crop well-suited to arid and semi-arid zones, providing income for farmers and cooperatives reliant on cactus fruit and derivatives.
Before the pest's incursion, the area planted with cactus in Morocco exceeded 150,000 hectares, but extensive losses have since occurred, prompting authorities to implement measures such as uprooting infected plants, using pesticides, and researching resistant varieties. This initiative has yielded notable results, with the National Institute for Agricultural Research identifying eight resistant varieties, which now underpin a program focused on replanting cacti.
According to the Institute, Morocco produced over 16.3 million resistant seedlings from 2021 to 2025, with a national program aiming to replant 122,000 hectares by 2028, backed by investments nearing 1.4 billion dirhams. Nonetheless, developing a plant resilient to pest attacks does not diminish the need to explore methods for directly combating the pest itself, particularly given the limitations associated with chemical pesticides and their environmental impact.
As a result, scientists are concurrently investigating more targeted biological control methods. The new study places the bacteria associated with the pest among these possibilities, having demonstrated that its composition varies across different regions and is linked to environmental factors. In the case of Al Hoceima, while a higher diversity of bacterial species does not imply that the insects there are more dangerous than those in Marrakech, it does afford researchers a broader spectrum of potential interactions between the pest and the microbes cohabiting with it.
The crucial test in the upcoming phase will be to ascertain whether disrupting any of these relationships genuinely affects the insect's ability to survive or reproduce. If experiments validate this, Morocco could introduce an additional method of combating the scale insect, targeting one of its biological needs rather than solely relying on pesticide interventions.
As reported by tanja24.com.
