The Costa Tropical, known for its lush avocado orchards, faces a significant threat from the ambrosia beetle (Euwallacea fornicatus). Recently detected on three farms in Motril, the insect has prompted the Spanish Ministry of Agriculture to declare its presence, along with the fungus it carries, a pest.
What is the ambrosia beetle?
The ambrosia beetle is a small wood-boring insect measuring just 2-3 millimetres. Native to Southeast Asia, it has spread globally, becoming a significant pest in regions where it has no natural predators.
Unlike many insects, the ambrosia beetle does not feed directly on the tree’s wood. Instead, it introduces a symbiotic fungus (Fusarium euwallaceae) into the tree as it bores tunnels into the trunk or branches. The beetle and its larvae feed on this fungus, but the fungus infects and disrupts the tree’s vascular system, leading to branch dieback and, in severe cases, the death of the tree.
The pest is particularly destructive to crops such as avocados, mangoes, and other subtropical fruit trees. It has caused extensive damage in the Americas, including in California and Central America, where avocado cultivation has been severely impacted.
Affected areas in Motril
As reported by Granada Hoy, three plots in Motril and two adjacent farms (one undeveloped) have been officially marked as contaminated. A one-kilometre buffer zone has been established around these sites to monitor and contain the pest. This zone will be updated as authorities gather more data.
The beetle’s impact extends beyond avocados, posing risks to other crops like mangoes and cherimoyas. Local farmers are now awaiting decisions on compensation for necessary measures, including tree pruning and removal.
Tracing the infestation
The source of the ambrosia beetle’s arrival remains unclear. Motril’s mayor, Luisa García Chamorro, highlighted the beetle’s history of causing severe damage to avocado cultivation in the Americas, raising concerns about how it reached Spain.
Since its initial detection in October 2023, officials have placed 20 traps across Motril and five in surrounding forested areas. To date, 18 infected trees have been removed in efforts to curb the beetle’s spread.
Mandatory measures to protect crops
To tackle the infestation, the Ministry of Agriculture has introduced a series of mandatory measures for affected farms:
- Monthly inspections: Farm owners must inspect for signs of the beetle and report findings to authorities.
- Access for authorities: Farmers must allow official access for further inspections and interventions.
- Immediate pruning: Infected primary branches close to the trunk or root collar must be pruned, and wounds sealed with healing paste.
- Tree removal: Trees confirmed or suspected to host the beetle must be cleared and destroyed within 20 days. Plant material must be shredded or otherwise destroyed immediately.
Preventing further spread
To isolate the pest, infected trees must be immediately quarantined. Additional restrictions include:
- Prohibiting the sharing of vehicles, crates, and fruit containers between farms.
- Ensuring thorough cleaning of tools, equipment, and other materials used in farming operations.
Broader implications for the Costa Tropical
The ambrosia beetle’s arrival could have devastating economic and environmental consequences for the Costa Tropical. Avocado farming is a cornerstone of the region’s agricultural industry, and the potential spread of the pest threatens other key crops, including mangoes and cherimoyas.
Farmers and authorities face an urgent challenge to contain the infestation and protect the region’s agricultural future. Further updates on contamination zones and pest control measures are expected as the situation develops.